U.S. patent application number 13/709521 was filed with the patent office on 2013-06-13 for metalworking fluid composition and method for its use in the machining of compacted graphite iron.
This patent application is currently assigned to QUAKER CHEMICAL CORPORATION. The applicant listed for this patent is Quaker Chemical Corporation. Invention is credited to Robert D. Evans, Steven R. Thomas, Kuan Zhong.
Application Number | 20130150271 13/709521 |
Document ID | / |
Family ID | 48572536 |
Filed Date | 2013-06-13 |
United States Patent
Application |
20130150271 |
Kind Code |
A1 |
Evans; Robert D. ; et
al. |
June 13, 2013 |
METALWORKING FLUID COMPOSITION AND METHOD FOR ITS USE IN THE
MACHINING OF COMPACTED GRAPHITE IRON
Abstract
Compositions and methods for reducing toolwear during
iron-machining, including applying a composition comprising water;
a lubricant ester; and a sulfur-containing lubricant additive.
Inventors: |
Evans; Robert D.;
(Warminster, PA) ; Zhong; Kuan; (Wayne, PA)
; Thomas; Steven R.; (Plymouth Meeting, PA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Quaker Chemical Corporation; |
Conshohocken |
PA |
US |
|
|
Assignee: |
QUAKER CHEMICAL CORPORATION
Conshohocken
PA
|
Family ID: |
48572536 |
Appl. No.: |
13/709521 |
Filed: |
December 10, 2012 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
61568979 |
Dec 9, 2011 |
|
|
|
Current U.S.
Class: |
508/195 ;
508/501 |
Current CPC
Class: |
C10M 2209/105 20130101;
C10M 2215/04 20130101; C10M 2203/1006 20130101; C10M 2207/28
20130101; C10M 2209/104 20130101; C10M 2219/08 20130101; C10M
2209/1095 20130101; C10M 2207/283 20130101; C10M 2209/1045
20130101; C10M 2209/109 20130101; C10M 2209/107 20130101; C10M
2227/061 20130101; C10M 2207/2835 20130101; C10M 2209/102 20130101;
C10M 2201/087 20130101; C10M 2209/1075 20130101; C10M 2209/1055
20130101; C10N 2030/06 20130101; C10M 2219/024 20130101; C10M
2207/401 20130101; C10M 2215/042 20130101; C10M 2227/06 20130101;
C10N 2040/246 20200501; C10M 2207/2805 20130101; C10M 173/00
20130101; C10M 2219/022 20130101; C10M 2227/063 20130101; C10M
2207/125 20130101; C10M 2219/082 20130101; C10M 2207/126 20130101;
C10M 2203/1025 20130101; C10M 2203/1065 20130101; C10M 2207/40
20130101; C10M 2209/1023 20130101; C10M 169/048 20130101; C10M
2209/104 20130101; C10M 2209/105 20130101; C10M 2209/109 20130101;
C10M 2209/1045 20130101; C10M 2209/1055 20130101; C10M 2209/1095
20130101; C10M 2209/105 20130101; C10M 2209/109 20130101; C10M
2209/1055 20130101; C10M 2209/1095 20130101; C10M 2209/104
20130101; C10M 2209/109 20130101; C10M 2209/1045 20130101; C10M
2209/1095 20130101 |
Class at
Publication: |
508/195 ;
508/501 |
International
Class: |
C10M 169/04 20060101
C10M169/04 |
Claims
1. An iron-machining composition comprising (a) water; (b) a
sulfur-containing lubricant additive; and (c) optionally containing
a lubricant ester in an amount of about 0 wt % to about 50 wt % of
the iron-machining composition.
2. The composition of claim 1, wherein the lubricant ester
comprises about 0.05 wt % to about 50 wt % of the iron-machining
composition.
3. The composition of claim 1, wherein the lubricant ester
comprises a polyol ester selected from those of C.sub.12 toC.sub.18
fatty acid esters of 2,2 dimethyl-1,3-propanediol, 2-propanol,
1,1,1, tris(hydroxymethyl)propane, 2-hydroxy-1,3-propanediol,
2,2-bis(hydroxymethyl)-1,3-propanediol, and 1,2,3-propanetriol.
4. The composition of claim 1, wherein the lubricant ester
comprises a glycerol-based ester.
5. The composition of claim 4, wherein the lubricant ester
comprises a glycerol ester of C.sub.12 to C.sub.18 saturated and
unsaturated fatty acids.
6. The composition of claim 5, wherein the ester is derived from
vegetable oils and animal fats.
7. The composition of claim 5, wherein the ester is synthetically
produced via the reaction of fatty acids with glycerol.
8. The composition of claim 1, wherein the lubricant ester
comprises a polyol ester produced by the initial reaction of the
polyol with ethylene oxide and/or propylene oxide followed by
subsequent esterification, to yield a polyoxyalkylated polyol
ester.
9. The composition of claim 1, wherein the lubricant ester
comprises a oligomeric or polymeric ester produced by the
condensation of hydroxyl-functionalized fatty acids, such as
ricinoleic acid.
10. The composition of claim 1, wherein the lubricant ester
comprises C.sub.18 fatty acid esters of 2,2
dimethyl-1,3-propanediol, 2-propanol, 1,1,1,
tris(hydroxymethyl)propane, 2-hydroxy-1,3-propanediol,
2,2-bis(hydroxymethyl)-1,3-propanedioI, 1,2,3-propanetriol, or
combinations thereof.
11. The composition of claim 1, wherein the lubricant ester is
present in an amount of less than about 50 wt % of the
iron-machining composition.
12. The composition of claim 1 wherein the sulfur-containing
lubricant additive is selected from the group consisting of
sulfurized alpha olefins, di-branched alkyl tri and polysulfides,
sulfur containing carboxylic acids, complex sulfurized esters,
and/or dialkyl polysufides.
13. The composition of claim 1, wherein the sulfur-containing
lubricant additive comprises a dialkyl polysufide selected from
those having a formula:
CH.sub.3--C(R.sub.1)(R.sub.2)--(CH.sub.2)n-).sub.x-S.sub.m whereby
R.sub.1.dbd.H or CH.sub.3, R.sub.2.dbd.H or CH.sub.3, n=8-20,
x=1-2, and m=2-7.
14. The composition of claim 1, wherein the sulfur-containing
lubricant additive is present in an amount of about 0.5 wt % to
about 7 wt %.
15. The composition of claim 1, further comprising fatty acids
selected from those containing saturated and unsaturated chains of
between 12 and 22 carbons, in an amount of about 0 wt % to about 12
wt %.
16. The composition of claim 1, further comprising about 3 wt % to
about 15 wt % of a mixture of amine compounds having a formula
R.sub.1(R.sub.2)--N--R, whereby R.sub.1.dbd.H, CH.sub.3 or
--CH.sub.2CH.sub.2OH, R.sub.2.dbd.H, CH3-(CH2).sub.n, whereby
n=0-22, --CH.sub.2CH.sub.2OH, or cyclic C.sub.6H.sub.11, and
R.sub.3.dbd.--(CH.sub.2CH.sub.2O).sub.m--H whereby m=1-12,
CH.sub.3--(CH.sub.2).sub.xO-- whereby x=0-8, or cyclic
C.sub.6H.sub.11.
17. The composition of claim 16, wherein the amine comprises
ethanolamine, triethanolamine, 2-amino-2-methyl propanol,
dicyclohexylamine, diglycolamine, or combinations thereof.
18. The composition of claim 1, further comprising about 0 wt % to
about 15 wt % of an amine-boric acid comprising alkanolamine borate
esters, amine polyborate, amine salts of boric acid, and
combinations thereof.
19. The composition of claim 1, further comprising about 0 wt % to
about 40 wt % of a mineral oil, the mineral oil comprising a
paraffinic oil, naphthenic oil, or mixtures thereof, with an
ambient pressure viscosity of between about 15 cSt and about 30 cSt
at 40 degrees centigrade.
20. The composition of claim 1, further comprising about 4 wt % to
about 10 wt % of a mixture of nonionic and anionic emulsifiers.
21. A method of machining iron, comprising applying the fluid
composition of claim 1 to the iron during machining.
22. A method of machining iron, comprising applying the fluid
composition of claim 1 in the form of a water dilution, to the iron
during machining.
23. A method according to claim 22, whereby the fluid composition
of claim 1 is diluted in water to a concentration of between 2% by
wt. to 50% by weight prior to use in machining of iron.
24. A method according to claim 22, whereby the fluid composition
of claim 1 is diluted in water to a concentration of between 2% by
wt. to 15% by weight prior to use in machining of iron
25. A method of reducing tool wear during machining of iron,
comprising applying the fluid composition of claim 1 at to the iron
during machining.
26. A method of claim 25 wherein reduced tool wear during machining
of iron is achieved by use of the fluid composition diluted in
water to a concentration of between 2% by wt to 50% by wt.
27. A method of claim 25 wherein reduced tool wear during machining
of iron, is achieved by use of the fluid composition diluted in
water to a concentration of between 2% by wt to 15% by wt.
28. The method of claim 25, wherein the tool wear is reduced by
about 5% to about 90% as compared to conventional lubricant
fluids.
29. The method of claim 21, wherein the iron comprises compacted
graphite iron.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority benefit from U.S.
Provisional Patent Application No. 61/568,979, filed on Dec. 9,
2011, which is incorporated by reference in its entirety.
BACKGROUND
[0002] Cast irons may be used in the production of many industrial
components. Certain types of cast irons such as compacted graphite
iron may be difficult to machine; the metal cutting and grinding
often necessary in the fabrication of industrial components may
present challenges and difficulties resulting in, for example,
rapid and accelerated rates of tool wear, as well as in reduced
quality of the part produced.
[0003] With much effort currently underway in industry to replace
standard gray cast irons with compacted graphite iron to produce
lighter and higher strength parts, it is useful to describe the
differences both structurally and compositionally which give rise
to the differences in the material properties and machinability of
these two metals. Gray cast iron has traditionally been used for
the production of engine blocks, cylinder heads, as well as various
other automotive components. The graphite in gray cast iron has a
flake-like structure. The predominance of interconnecting graphite
flakes gives rise to a high level of discontinuities and stress
concentration effects in the matrix and subsequently gives rise to
the properties characteristic of gray irons such as good thermal
conductivity, damping capacity, and good machinability properties.
Thus gray cast iron is easily machined at low production costs,
(higher metal removal rates with long tool life). Different from
gray cast iron, compacted graphite iron has a graphite structure
much like that of coral. Such a graphite structure produces lower
levels of discontinuities and stress concentration effects within
the metal, giving rise to higher strength and toughness properties,
as well as lower machinability.
[0004] In addition to graphite structure differences, there are
significant compositional differences between gray cast iron and
compacted graphite iron which also are largely responsible for the
differences in the machinability of these two metals. The presence
of sulfur in gray cast iron is considered to be a critical factor
associated with the high machinability of this metal.
[0005] Due to these two factors (graphite morphology and sulfur
concentration) the machinability of compacted graphite iron is
considerably lower, and tool wear is considerably higher than that
experienced in gray cast iron machining. Previously reported
studies, show that tool life for milling and drilling operations of
compacted graphite iron can be one half, while tool life in
compacted graphite iron boring operations have been seen to be just
one-tenth of that obtained in comparable machining operations with
gray cast iron. Thus it has been clear that there has existed a
need for technology advances enabling for improved and more
economical machining of compacted graphite iron. Research and
development in areas of tool engineering, optimization of machining
conditions, compacted graphite iron composition, as well as
metalworking fluid composition. The current invention describes new
fluid compositions and methods of use which can provide enhanced
tool life and part quality in the machining of common grades of
compacted graphite iron.
SUMMARY OF THE INVENTION
[0006] According to some embodiments of the present invention, an
iron-machining composition includes water; a lubricant ester; and a
sulfur-containing lubricant additive. In some embodiments, a
lubricant ester or combination of lubricant esters is present in an
amount of about 1 wt % to about 50 wt %, and may include a polyol
ester; a glycerol-based ester; and/or an ester selected from those
of C.sub.12 toC.sub.18 fatty acid esters of 2,2
dimethyl-1,3-propanediol, 2-propanol, 1,1,1,
tris(hydroxymethyl)propane, 2-hydroxy-1,3-propanediol,
2,2-bis(hydroxymethyl)-1,3-propanediol, and 1,2,3-propanetriol.
Suitable esters also may include those produced by the initial
reaction of the polyol with ethylene oxide and/or propylene oxide
followed by subsequent esterification, to yield a polyoxyalkylated
polyol ester. Suitable esters also include those produced by the
condensation of hydroxyl-functionalized fatty acids, such as
ricinoleic acid, to yield oligomeric and polymeric esters.
[0007] In some embodiments, a sulfur-containing lubricant additive
is present in an amount of about 0.1 wt % to about 20 wt % and may
include sulfurized alpha olefins, di-branched alkyl tri and
polysulfides, sulfur containing carboxylic acids, complex
sulfurized esters, and/or a dialkyl polysufide selected from those
having a formula:
CH.sub.3--C(R.sub.1)(R.sub.2)--(CH.sub.2)n-).sub.x-S.sub.m, whereby
R.sub.1.dbd.H or CH.sub.3, R.sub.2.dbd.H or CH.sub.3, n=8-20,
x=1-2, and m=2-7.
[0008] In some embodiments, an iron-machining composition includes
fatty acids such as those containing saturated and unsaturated
chains of between 12 and 22 carbons, in an amount of about 0 wt %
to about 12 wt %.
[0009] In some embodiments, an iron-machining composition includes
about 0 wt % to about 10 wt % of a mixture of amine compounds
having a formula R.sub.1(R.sub.2)--N--R.sub.3, whereby
R.sub.1.dbd.H, CH.sub.3 or --CH.sub.2CH.sub.2OH, R.sub.2.dbd.H,
CH3-(CH2).sub.n, whereby n=0-22, --CH.sub.2CH.sub.2OH, or cyclic
C.sub.6H.sub.11, and R.sub.3.dbd.--(CH.sub.2CH.sub.2O).sub.m--H
whereby m=1-12, CH3-(CH2).sub.xO-- whereby x=0-8, or cyclic
C.sub.6H.sub.11.
[0010] In some embodiments, an iron-machining composition includes
about 0 wt % to about 30 wt % of a boric acid-amine adduct whereby
the boric acid amine adduct may be comprised of a mixture of one or
more structures including the amine salts of boric acid, boric
acid-alkonaolamine esters including cyclic boroxine esters, and
polyborate amine salts.
[0011] In some embodiments, an iron-machining composition includes
about 0 wt % to about 50 wt % of a mineral oil. Suitable mineral
oils may be pure or a mixture of mineral oils such as naphthenic
and paraffinic oils of between about 15 cSt and about 30 cSt at 40
degrees centigrade.
[0012] In some embodiments, an iron-machining composition includes
about 4 wt % to about 10 wt % of a mixture of nonionic and anionic
emulsifiers.
[0013] According to some embodiments, a method of machining iron
includes applying a fluid composition of the present invention
(referred to as fluid concentrate) as a water dilution whereby
prior to use in machining, the composition of the present invention
is first diluted with water to give between 1% to 100%
concentration of the fluid concentrate. In some embodiments, such
application may reduce tool wear during machining of iron such as
by about 5% to about 90% as compared to conventional lubricant
fluids. In some embodiments, the machined iron is compacted
graphite iron.
DESCRIPTION OF THE DRAWINGS
[0014] FIG. 1 shows axial forces measured during drilling;
[0015] FIG. 2 shows torque measured during drilling;
[0016] FIG. 3 illustrates tool wear after drilling;
[0017] FIG. 4 shows tool wear with various machining fluids;
[0018] FIG. 5 shows cutting forces with various machining
fluids;
[0019] FIG. 6 shows tool wear obtained on drills; and
[0020] FIG. 7 shows the surface finish measured over one hundred
thirty holes reamed.
DETAILED DESCRIPTION OF THE INVENTION
[0021] Compositions and methods of some embodiments of the present
invention relate to metalworking fluid compositions and methods for
their use in the machining of metal, such as iron. In some
embodiments, compositions and methods of the present invention
relate to machining compacted graphite iron (also referred to as
"CGI" or "vermicular iron"). In some embodiments, fluid
compositions and methods of application of the present invention
which, when used in the metal cutting and grinding processes
performed on iron such as compacted graphite iron, may
significantly extend the lifetime of the tools used by effectively
reducing wear, and may improve the quality of the part produced. In
some embodiments, fluid compositions of the present invention
include at least an ester lubricant in combination with a
sulfur-containing lubricant additive.
[0022] Ester Lubricant
[0023] In some embodiments, fluid compositions of the present
invention include one or more ester lubricants. Suitable ester
lubricants may include polyol and natural carboxylic esters such as
long chain (C.sub.12-C.sub.22) carboxylic esters of branched
chained or cyclic mono, di and polybasic alcohols. Suitable ester
lubricants may also include alkoxylated polyol esters such as long
chain (C.sub.12-C.sub.22) carboxylic esters of branched chained or
cyclic mono, di and polybasic alcohols whereby the polybasic
alcohol is alkoxylated prior to formation of the carboxylic ester.
Suitable esters may also include those produced by the condensation
of hydroxyl-functionalized fatty acids, such as ricinoleic acid, to
yield oligomeric and polymeric esters. In some embodiments,
suitable ester lubricants include esters containing a carboxylic
acid moiety selected from carboxylic acids with saturated and
unsaturated alkyl chains of between 12 to 22 carbons in length,
whereby fatty acid(s) are reacted with a mono or polyfunctional
alcohol selected from but not limited to 2,2
dimethyl-1,3-propanediol, 2-propanol, 1,1,1,
tris(hydroxymethyl)propane, 2-hydroxy-1,3-propanediol,
2,2-bis(hydroxymethyl)-1,3-propanediol, and 1,2,3-propanetriol, to
form the ester useful within the current invention.
[0024] In some embodiments, a fluid composition contains an ester
lubricant in an amount of about 1 wt % to about 50 wt % of the
fluid composition; about 2 wt % to about 40 wt % of the fluid
composition; about 3 wt % to about 35 wt % of the fluid
composition; about 4 wt % to about 30 wt % of the fluid
composition; about 5 wt % to about 25 wt % of the fluid
composition; about 6 wt % to about 20 wt % of the fluid
composition; about 6 wt % to about 15 wt % of the fluid
composition; about 7 wt % to about 10 wt % of the fluid
composition; about 1 wt % of the fluid composition; about 2 wt % of
the fluid composition; about 4 wt % of the fluid composition; about
6 wt % of the fluid composition; about 8 wt % of the fluid
composition; about 10 wt % of the fluid composition; about 12 wt %
of the fluid composition; about 14 wt % of the fluid composition;
about 16 wt % of the fluid composition; about 18 wt % of the fluid
composition; about 20 wt % of the fluid composition; about 22 wt %
of the fluid composition; about 24 wt % of the fluid composition;
about 26 wt % of the fluid composition; about 28 wt % of the fluid
composition; about 30 wt % of the fluid composition; about 32 wt %
of the fluid composition; about 34 wt % of the fluid composition;
about 36 wt % of the fluid composition; about 38 wt % of the fluid
composition; about 40 wt % of the fluid composition; about 42 wt %
of the fluid composition; about 44 wt % of the fluid composition;
about 46 wt % of the fluid composition; about 48 wt % of the fluid
composition; and about 50 wt % of the fluid composition.
[0025] Sulfur-Containing Lubricant Additives
[0026] In some embodiments, a fluid composition of the present
invention includes one or more sulfur-containing lubricant
additives. Suitable sulfur-containing additives may include
sulfurized alpha olefins, di-branched alkyl tri and polysulfides,
sulfur containing carboxylic acids, complex sulfurized esters,
and/or dialkyl polysufides.
[0027] In some embodiments, suitable sulfur-containing compound
include structures as shown in Formula 1:
CH.sub.3--C(R.sub.1)(R.sub.2)--(CH.sub.2)n-).sub.x-S.sub.m Formula
1: [0028] whereby R.sub.1.dbd.H or CH.sub.3, R.sub.2.dbd.H or
CH.sub.3, n=8-20, x=1-2, and m=2-7.
[0029] In some embodiments, a fluid composition include a
sulfur-containing lubricant additive in an amount of about 0.1 wt %
to about 20 wt % of the fluid composition; about 0.2 wt % to about
18 wt % of the fluid composition; about 0.3 wt % to about 16 wt %
of the fluid composition; about 0.4 wt % to about 14 wt % of the
fluid composition; about 0.5 wt % to about 12 wt % of the fluid
composition; about 0.6 wt % to about 10 wt % of the fluid
composition; about 0.7 wt % to about 10 wt % of the fluid
composition; about 0.8 wt % to about 9 wt % of the fluid
composition; about 0.9 wt % to about 8 wt % of the fluid
composition; about 1 wt % to about 7 wt % of the fluid composition;
about 7 wt % of the fluid composition; about 0.1 wt % of the fluid
composition; about 0.2 wt % of the fluid composition; about 0.4 wt
% of the fluid composition; about 0.5 wt % of the fluid
composition; about 0.6 wt % of the fluid composition; about 0.8 wt
% of the fluid composition; about 1 wt % of the fluid composition;
about 2 wt % of the fluid composition; about 3 wt % of the fluid
composition; about 4 wt % of the fluid composition; about 5 wt % of
the fluid composition; about 6 wt % of the fluid composition; about
7 wt % of the fluid composition; about 8 wt % of the fluid
composition; about 9 wt % of the fluid composition; about 10 wt %
of the fluid composition; about 12 wt % of the fluid composition;
about 14 wt % of the fluid composition; about 16 wt % of the fluid
composition; about 18 wt % of the fluid composition; or about 20 wt
% of the fluid composition.
[0030] In addition to the above two components of the metalworking
fluid, the composition of this invention may also contain other
compounds commonly used in many metal cutting lubricant fluids.
Such compounds and concentration of such compounds are described
below.
[0031] Fatty Acids
[0032] In some embodiments, a fluid composition of the present
invention includes fatty acids. Suitable fatty acids may include
but are not limited to those of between 12 and 22 carbons in chain
length incorporated into the formula as a single fatty acid type or
as a combination of two or more fatty acids.
[0033] In some embodiments, a fluid composition of the present
invention includes fatty acids in an amount of about 0 wt % to
about 30 wt % of the fluid composition; about 0.1 wt % to about 30
wt % of the fluid composition; about 0.5 wt % to about 25 wt % of
the fluid composition; about 1 wt % to about 20 wt % of the fluid
composition; about 2 wt % to about 17 wt % of the fluid
composition; about 3 wt % to about 15 wt % of the fluid
composition; about 0.1 wt % of the fluid composition; about 0.5 wt
% of the fluid composition; about 1 wt % of the fluid composition;
about 2 wt % of the fluid composition; about 3 wt % of the fluid
composition; about 4 wt % of the fluid composition; about 5 wt % of
the fluid composition; about 6 wt % of the fluid composition; about
7 wt % of the fluid composition; about 8 wt % of the fluid
composition; about 9 wt % of the fluid composition; about 10 wt %
of the fluid composition; about 11 wt % of the fluid composition;
about 12 wt % of the fluid composition; about 13 wt % of the fluid
composition; about 14 wt % of the fluid composition; about 15 wt %
of the fluid composition; about 17 wt % of the fluid composition;
about 20 wt % of the fluid composition; about 22 wt % of the fluid
composition; about 25 wt % of the fluid composition; about 27 wt %
of the fluid composition; or about 30 wt % of the fluid
composition.
[0034] Amines
[0035] In some embodiments, a fluid composition of the present
invention includes an amine or mixture of amine compounds. Suitable
amines may include but are not limited to those having a formula
R.sub.1(R.sub.2)--N--R.sub.3, whereby R.sub.1.dbd.H, CH.sub.3 or
--CH.sub.2CH.sub.2OH, R.sub.2.dbd.H, CH3-(CH2).sub.n, whereby
n=0-22, --CH.sub.2CH.sub.2OH, or cyclic C.sub.6H.sub.11, and
R.sub.3.dbd.--(CH.sub.2CH.sub.2O).sub.m--H whereby m=1-12,
CH.sub.3--(CH.sub.2).sub.xO-- whereby x=0-8, or cyclic
C.sub.6H.sub.11. Such amines include ethanolamine, triethanolamine,
2-amino-2-methyl propanol, dicyclohexylamine, and
diglycolamine.
[0036] In certain embodiments, a fluid composition of the present
invention includes an amine or mixture of amines in an amount of
about 0 wt % to about 30 wt % of the fluid composition; about 0.1
wt % to about 30 wt % of the fluid composition; about 0.5 wt % to
about 25 wt % of the fluid composition; about 1 wt % to about 20 wt
% of the fluid composition; about 2 wt % to about 17 wt % of the
fluid composition; about 3 wt % to about 15 wt % of the fluid
composition; about 0.1 wt % of the fluid composition; about 0.5 wt
% of the fluid composition; about 1 wt % of the fluid composition;
about 2 wt % of the fluid composition; about 3 wt % of the fluid
composition; about 4 wt % of the fluid composition; about 5 wt % of
the fluid composition; about 6 wt % of the fluid composition; about
7 wt % of the fluid composition; about 8 wt % of the fluid
composition; about 9 wt % of the fluid composition; about 10 wt %
of the fluid composition; about 11 wt % of the fluid composition;
about 12 wt % of the fluid composition; about 13 wt % of the fluid
composition; about 14 wt % of the fluid composition; about 15 wt %
of the fluid composition; about 17 wt % of the fluid composition;
about 20 wt % of the fluid composition; about 22 wt % of the fluid
composition; about 25 wt % of the fluid composition; about 27 wt %
of the fluid composition; or about 30 wt % of the fluid
composition.
[0037] Amine-Boric Acid Adducts
[0038] In some embodiments, a fluid composition of the present
invention includes a boric acid-amine adduct whereby the boric acid
amine adduct may be comprised of a mixture of one or more
structures which include the amine salts of boric acid, boric
acid-alkonaolamine esters including cyclic boroxine esters, as well
as polyborate amine salts. Suitable adducts can be prepared by the
reaction of boric acid with a single or mixtures of amines selected
from but not limited to monoethanolamine, triethanolamine,
2-amino-2-methyl propanol, dicyclohexylamine, and diglycolamine,
reacted at either stoichiometric quantities or with slight excess
of the amine component.
[0039] In certain embodiments, a fluid composition of the present
invention includes an amine boric acid adduct in an amount of about
0.1 wt % to about 30 wt % of the fluid composition; about 1 wt % to
about 25 wt % of the fluid composition; about 2 wt % to about 20 wt
% of the fluid composition; about 3 wt % to about 17 wt % of the
fluid composition; about 5 wt % to about 15 wt % of the fluid
composition; about 0.1 wt % of the fluid composition; about 0.5 wt
% of the fluid composition; about 1 wt % of the fluid composition;
about 2 wt % of the fluid composition; about 3 wt % of the fluid
composition; about 4 wt % of the fluid composition; about 5 wt % of
the fluid composition; about 6 wt % of the fluid composition; about
7 wt % of the fluid composition; about 8 wt % of the fluid
composition; about 9 wt % of the fluid composition; about 10 wt %
of the fluid composition; about 11 wt % of the fluid composition;
about 12 wt % of the fluid composition; about 13 wt % of the fluid
composition; about 14 wt % of the fluid composition; about 15 wt %
of the fluid composition; about 17 wt % of the fluid composition;
about 20 wt % of the fluid composition; about 22 wt % of the fluid
composition; about 25 wt % of the fluid composition; about 27 wt %
of the fluid composition; or about 30 wt % of the fluid
composition.
[0040] Amine Salt of Dicarboxylic Acid
[0041] In some embodiments, a fluid composition of the present
invention includes an amine salt of a short chain dicarboxylic
acid. Suitable amine salts of short chain dicarboxylic acids
include but are not limited to those whereby the amine diacid acid
salt is comprised of a single or mixture of amines selected from
monoethanolamine, triethanolamine, 2-amino-2-methyl propanol,
dicyclohexylamine, and diglycolamine, reacted with a short chain
dicarboxylic acid selected from those containing between 4-12
carbon atoms.
[0042] In certain embodiments of the present invention, a fluid
composition includes one or more amine salts of a short chain
dicarboxylic acid in an amount of about 0.1 wt % to about 20 wt %
of the fluid composition; about 0.5 wt % to about 15 wt % of the
fluid composition; about 1 wt % to about 10 wt % of the fluid
composition; about 1.5 wt % to about 9 wt % of the fluid
composition; about 2 wt % to about 8 wt % of the fluid composition;
about 0.1 wt % of the fluid composition; about 0.5 wt % of the
fluid composition; about 1 wt % of the fluid composition; about 1.5
wt % of the fluid composition; about 2 wt % of the fluid
composition; about 3 wt % of the fluid composition; about 4 wt % of
the fluid composition; about 5 wt % of the fluid composition; about
6 wt % of the fluid composition; about 7 wt % of the fluid
composition; about 8 wt % of the fluid composition; about 9 wt % of
the fluid composition; about 10 wt % of the fluid composition;
about 12 wt % of the fluid composition; about 14 wt % of the fluid
composition; about 16 wt % of the fluid composition; about 18 wt %
of the fluid composition; or about 20 wt % of the fluid
composition.
[0043] Mineral Oil
[0044] In some embodiments, a fluid composition of the present
invention includes a mineral oil. Suitable mineral oils may be pure
or a mixture of mineral oils such as naphthenic and paraffinic
oils. In some embodiments, a suitable mineral oil or mineral oil
blend may have a final viscosity of about 5 cSt to about 35 cSt at
40 degrees centigrade; about 10 cSt to about 30 cSt at 40 degrees
centrigrade; about 15 cSt to about 25 cSt at 40 degrees
centrigrade; about 5 cSt at 40 degree centigrade; about 10 cSt at
40 degree centigrade; about 15 cSt at 40 degree centigrade; about
20 cSt at 40 degree centigrade; about 25 cSt at 40 degree
centigrade; about 30 cSt at 40 degree centigrade; or about 35 cSt
at 40 degree centigrade.
[0045] In certain embodiments, a fluid composition of the present
invention includes a mineral oil or mineral oil blend in an amount
of about 0 wt % to about 75 wt % of the fluid composition; about
0.1 wt % to about 75 wt % of the fluid composition; about 0.1 wt %
to about 70 wt % of the fluid composition; about 0.1 wt % to about
65 wt % of the fluid composition; about 0.1 wt % to about 60 wt %
of the fluid composition; about 0.1 wt % to about 55 wt % of the
fluid composition; about 1 wt % to about 50 wt % of the fluid
composition; about 2 wt % to about 45 wt % of the fluid
composition; about 5 wt % to about 40 wt % of the fluid
composition; about 10 wt % to about 35 wt % of the fluid
composition; about 15 wt % to about 30 wt % of the fluid
composition; about 20 wt % to about 25 wt % of the fluid
composition; about 0.1 wt % of the fluid composition; about 0.5 wt
% of the fluid composition; about 1 wt % of the fluid composition;
about 2 wt % of the fluid composition; about 5 wt % of the fluid
composition; about 10 wt % of the fluid composition; about 15 wt %
of the fluid composition; about 20 wt % of the fluid composition;
about 25 wt % of the fluid composition; about 30 wt % of the fluid
composition; about 35 wt % of the fluid composition; about 40 wt %
of the fluid composition; about 45 wt % of the fluid composition;
about 50 wt % of the fluid composition; about 55 wt % of the fluid
composition; about 60 wt % of the fluid composition; about 65 wt %
of the fluid composition; about 70 wt % of the fluid composition;
or about 75 wt % of the fluid composition.
[0046] Emulsifiers
[0047] In some embodiments, a fluid composition of the present
invention includes one or more emulsifiers. Suitable emulsifiers
may include but are not limited to a mixture of nonionic and
anionic emulsifiers selected from those commonly known in the art
and typically used in water based metalworking fluids. In some
embodiments, suitable emulsifiers include alkaline metal salts of
alkylaryl, alkyl and aryl sulfonic acids; alkoxylated long chain
alcohols of between C.sub.12-C.sub.22 in length;
polyooxyethylene/polyoxypropylene copolymers; and ethoxylated alkyl
phenols.
[0048] In some embodiments, a fluid composition of the present
invention includes one or more emulsifiers in an amount of about
0.1 wt % to about 20 wt % of the fluid composition; about 0.5 wt %
to about 18 wt % of the fluid composition; about 1 wt % to about 16
wt % of the fluid composition; about 2 wt % to about 14 wt % of the
fluid composition; about 2 wt % to about 12 wt % of the fluid
composition; about 3 wt % to about 11 wt % of the fluid
composition; about 4 wt % to about 10 wt % of the fluid
composition; about 0.1 wt % of the fluid composition; about 0.5 wt
% of the fluid composition; about 1 wt % of the fluid composition;
about 2 wt % of the fluid composition; about 3 wt % of the fluid
composition; about 4 wt % of the fluid composition; about 5 wt % of
the fluid composition; about 6 wt % of the fluid composition; about
7 wt % of the fluid composition; about 8 wt % of the fluid
composition; about 9 wt % of the fluid composition; about 10 wt %
of the fluid composition; about 11 wt % of the fluid composition;
about 12 wt % of the fluid composition; about 13 wt % of the fluid
composition; about 14 wt % of the fluid composition; about 15 wt %
of the fluid composition; about 16 wt % of the fluid composition;
about 17 wt % of the fluid composition; about 18 wt % of the fluid
composition; about 19 wt % of the fluid composition; or about 20 wt
% of the fluid composition.
[0049] Composition
[0050] A metalworking fluid composition described according to the
present invention and suitable for use in the machining of iron
such as compacted graphite iron consists of:
[0051] a) about 5 wt % to about 40 wt % of a lubricant ester or
combination of lubricant esters selected from synthetic polyol
fatty acid esters such as trimethyolpropane trioleate,
pentaerythritol tetradodecanoate, neopentylglycol dioleate, and
isopropyl oleate as well as those produced by the initial reaction
of the polyol with ethylene oxide and/or propylene oxide followed
by subsequent esterification, to yield a polyoxyalkylated polyol
ester. As well as those produced by the condensation of
hydroxyl-functionalized fatty acids, such as ricinoleic acid, to
yield oligomeric and polymeric esters.
[0052] b) about 1 wt % to about 10 wt % of a sulfur-containing
compound selected from di-branched alkyl polysulfides, sulfurized
alpha olefins and complex sulfurized fatty acids and fatty acid
esters;
[0053] c) about 0 wt % to about 12 wt % fatty acids selected from
those of between 12 and 22 carbons in chain length which can be
incorporated into the fluid as a single fatty acid or as a
combination of two or more fatty acids;
[0054] d) about 3 wt % to about 15 wt % of an amine or mixture of
amine compounds, selected from but not limited to those to those
having a formula R.sub.1(R.sub.2)--N--R.sub.3, whereby
R.sub.1.dbd.H, CH.sub.3 or CH.sub.2CH.sub.2OH, R.sub.2.dbd.H,
CH3-(CH2).sub.n, whereby n=0-22, --CH.sub.2CH.sub.2OH, or cyclic
C.sub.6H.sub.11, and R.sub.3.dbd.--(CH.sub.2CH.sub.2O).sub.m--H
whereby m=1-12, CH.sub.3--(CH.sub.2).sub.xO-- whereby x=0-8, or
cyclic C.sub.6H.sub.11. Such amines include ethanolamine,
triethanolamine, 2-amino-2-methyl propanol, dicyclohexylamine, and
diglycolamine.
[0055] e) about 0 wt % to about 15 wt % of a boric acid-amine
adduct whereby the boric acid amine adduct may be comprised of a
mixture of one or more structures which include the amine salts of
boric acid, boric acid-alkonaolamine esters including cyclic
boroxine esters, as well as polyborate amine salts.
[0056] e) about 0 wt % to about 40 wt % of a paraffinic or
naphthenic based mineral oil with an ambient temperature viscosity
of between about 4 cSt to about 28 cSt.
[0057] Such fluid compositions, when blended in an amount of about
2 wt % to about 15 wt % in water, and utilized in the machining of
iron such as compacted graphite iron, produce a significant
decrease in the rate of tool wear which occurs as well as a
noticeable enhancement in the quality of the part machined.
[0058] In another embodiment of the current invention, a fluid
useful for the improved machining of iron such as compacted
graphite iron includes:
[0059] a) about 5 wt % to about 15 wt % of a lubricant ester or
combination of lubricant esters selected from those of C.sub.18
fatty acid esters of 2,2 dimethyl-1,3-propanediol, 2-propanol,
1,1,1, tris(hydroxymethyl)propane, 2-hydroxy-1,3-propanediol,
2,2-bis(hydroxymethyl)-1,3-propanediol, and 1,2,3-propanetriol;
[0060] b) about 2 wt % to about 5 wt % of a dialkyl polysufide
selected from those according to Formula 1 whereby
R.sub.1.dbd.CH.sub.3, R.sub.2.dbd.CH.sub.3, n=8-10 and m=3-5;
[0061] c) about 6 wt % to about 12 wt % fatty acids selected from
those containing saturated and unsaturated chains of between 16 and
22 carbons;
[0062] d) about 3 wt % to about 10 wt % of a mixture of amine
compounds, such as those described by Formula 2:
R.sub.1(R.sub.2)--N--R Formula 2:
[0063] whereby R.sub.1.dbd.H or --CH.sub.2CH.sub.2OH,
R.sub.2.dbd.H, or --CH.sub.2CH.sub.2OH, or cyclic C.sub.6H.sub.11,
and R.sub.3.dbd. or --CH.sub.2CH.sub.2OH, or cyclic
C.sub.6H.sub.11;
[0064] e) about 10 wt % to about 14 wt % of an amine-boric acid
adduct according to the structure shown in Formula 3:
B(O.sup.- HN.sup.+(CH.sub.2CH.sub.2OH).sub.n).sub.m Formula 3:
[0065] whereby n=m=3;
[0066] f) about 30 wt % to about 40 wt % of a naphthenic-based
mineral oil with an ambient pressure viscosity of between about 15
cSt and about 30 cSt at 40 degrees centigrade; and
[0067] g) about 4 wt % to about 10 wt % of a mixture of nonionic
and anionic emulsifiers selected from those commonly known in the
art and typically used in water based metalworking fluids.
[0068] Such fluid compositions, when blended in an amount of about
3 wt % to about 15% in water, and utilized in the machining of iron
such as compacted graphite iron, produce a noticeable decrease in
the rate of tool wear which occurs as well as a noticeable
enhancement in the quality of the part machined. Results of
machining tests described below show the utility and advancement
realized with such compositions in the machining of iron such as
compacted graphite iron.
[0069] In some embodiments, fluid compositions of the present
invention may be blended with water to prepare a dilution. In some
embodiments, fluid compositions of the present invention may be
blended in water in an amount of about 1 wt % to about 50 wt % of
the dilution; about 2 wt % to about 25 wt % of the dilution; about
3 wt % to about 20 wt % of the dilution; about 3 wt % to about 17
wt % of the dilution; about 4 wt % to about 15 wt % of the
dilution; about 1 wt % of the dilution; about 2 wt % of the
dilution; about 3 wt % of the dilution; about 4 wt % of the
dilution; about 5 wt % of the dilution; about 6 wt % of the
dilution; about 7 wt % of the dilution; about 8 wt % of the
dilution; about 9 wt % of the dilution; about 10 wt % of the
dilution; about 11 wt % of the dilution; about 12 wt % of the
dilution; about 13 wt % of the dilution; about 14 wt % of the
dilution; about 15 wt % of the dilution; about 17 wt % of the
dilution; about 20 wt % of the dilution; about 25 wt % of the
dilution; or about 30 wt % of the dilution.
[0070] In some embodiments, use of fluid compositions according to
embodiments of the present invention during machining iron such as
compacted graphite iron results in a reduction in tool wear as
compared to conventional fluids of about 5% to about 95%; about 10%
to about 90%; about 15% to about 85%; about 20% to about 80%; about
25% to about 75%; about 30% to about 70%; about 35% to about 65%;
about 40% to about 60%; about 5%; about 10%; about 15%; about 20%;
about 25%; about 30%; about 35%; about 40%; about 45%; about 50%;
about 55%; about 60%; about 65%; about 70%; about 75%; about 80%;
about 85%; about 90%; or about 95%.
EXAMPLES
[0071] To assess the performance of a preferred composition as
described according to the present invention, drilling of Grade 450
compacted graphite iron was performed. Drilling is a process
whereby holes are produced in the workpiece metal, and in such,
greater amounts of metal are removed, which typically requires
greater cutting forces and gives rise to more severe mechanical and
thermal conditions in the process. Assessment of fluid performance
is made by measurement of the cutting forces and tool wear
occurring during the drilling operation.
Example 1
[0072] In this example, a standard conventional ferrous machining
fluid was assessed relative to a fluid described according to
embodiments of the current invention.
[0073] Fluid A, useful for the improved machining of compacted
graphite iron, was prepared according to embodiments of the present
invention having:
[0074] a) about 5 wt % to about 10 wt % ester lubricant;
[0075] b) about 3 wt % to about 7 wt % of a sulfur additive;
[0076] c) 8 wt % to about 16 wt % mineral oil; and
[0077] d) the balance having amines, boric acid, fatty acids, and
emulsifiers.
[0078] Fluid A was tested at a concentration of 8%. The machining
conditions are as follows:
TABLE-US-00001 CGI Drilling Workpiece Grade 450 CGI Tool Gehring #
5514 0.25'' dia. Firex coated solid carbide Speed 3000 RPM (196
SFM) Feed 10.4 IPM (.00346 ipr) Depth 1.25'' through hole Fluid 8%
in 130 ppm water Measured Parameters Cutting Forces Tool Wear CGI
Drilling
[0079] The axial machining forces and torque (tangential forces)
measured during drilling provide a useful indication of the
friction in the cutting zone and the lubrication provided by the
metalworking fluid. The change in the forces measured as drilling
continues may provide a useful indirect measure of the change or
deterioration in the condition of the tool, typically arising from
tool wear and/or metal adhesion on the cutting edge. As seen in the
results obtained and plotted in FIGS. 1 and 2, use of Fluid A
(embodiment of current invention) enables for the machining of
compacted graphite iron at considerably lower cutting forces and
change in forces relative to that which occurs when the
conventional ferrous machining fluid (Fluid B) is used.
[0080] In assessing the impact on the tool wear which occurs, it
can be seen that the flank wear formed on the drill used during
machining with the conventional ferrous machining fluid (Fluid B)
resulted in about 69.2% greater wear on the flank face of the
tool's cutting edge, relative to that obtained when using the fluid
composition described in the current invention (Fluid A). Thus from
both the cutting forces measured and the tool wear measured, the
benefit and utility offered by the composition described in the
current invention, is clearly seen in the drilling operation
conducted.
Example 2
[0081] Fluid D, useful for the improved machining of compacted
graphite iron, was prepared according to embodiments of the present
invention having:
[0082] a) about 22 wt % to about 28 wt % of a lubricant ester
selected from either the C.sub.18 fatty acid ester of 2,2
dimethyl-1,3-propanediol, 2-propanol, 1,1,1,
tris(hydroxymethyl)propane, or 1,2,3-propanetriol;
[0083] b) about 2 wt % to about 5 wt % of a dialkyl polysufide
selected from those according to Formula 1 whereby
R.sub.1.dbd.CH.sub.3, R.sub.2.dbd.CH.sub.3, n=8-10 and m=3-5;
[0084] c) about 3 wt % to about 6 wt % fatty acids comprised of
those which include saturated alkyl chains of between 10 to 16
carbons along with longer chain length carboxylic acids comprised
of saturated and unsaturated alkyl chains of between 18 to 22
carbon atoms in length.
[0085] d) about 3 wt % to about 8 wt % of a mixture of amine
compounds, consisting of those described by Formula 2, whereby
R.sub.1.dbd.H or --CH.sub.3, R.sub.2.dbd.--CH.sub.2CH.sub.2OH, or
cyclic C.sub.6H.sub.11, and R.sub.3.dbd.--CH.sub.2CH.sub.2OH, or
cyclic C.sub.6H.sub.11;
[0086] e) about 35 wt % to about 45 wt % of a naphthenic-based
mineral oil with an ambient pressure viscosity of between about 15
cSt to about 30 cSt at 40 degrees centigrade; and
[0087] f) about 4 wt % to about 10 wt % of a mixture of nonionic
and anionic emulsifiers selected from those commonly known in the
art and typically used in water-based metalworking fluids.
[0088] Such fluid compositions, when in an amount of about 4 wt %
to 15 wt % in water, and utilized in the machining of iron such as
compacted graphite iron, produce a noticeable decrease in the rate
of tool wear which occurs as well as a noticeable enhancement in
the quality of the part machined. Fluid D was tested in drilling
tests along with two currently used compacted graphite iron
machining fluids which are based on conventional ferrous machining
fluid compositions. These two fluids designated Fluid C and Fluid
E, both represent the state of the art technology available for
compacted graphite iron machining prior to that of the current
fluid compositions described in this invention. Also included in
this testing and comparison is Fluid A.
[0089] The results of tool wear measured during compacted graphite
iron drilling using the four fluids is shown below in FIGS. 3 and
4. The results demonstrate that Fluid A and Fluid D clearly yield a
significant reduction in tool wear, and thus extend the useful
duration of the tooling. The results show that Fluid A and Fluid D
result in a range of tool wear reduction between about 22% to about
46% representing significant benefit with regard to the machining
operations and the cost associated with the process.
Example 3
[0090] Fluid F, useful for the improved machining of compacted
graphite iron, was prepared according to embodiments of the present
invention having:
[0091] a) about 12 wt % to about 18 wt % of a lubricant ester or
combination of lubricant esters selected from those of C.sub.18
fatty acid esters of 2,2 dimethyl-1,3-propanediol, 2-propanol,
1,1,1, tris(hydroxymethyl)propane, 2-hydroxy-1,3-propanediol,
2,2-bis(hydroxymethyl)-1,3-propanediol, and 1,2,3-propanetriol. b)
between 2 and 5% of a dialkyl polysufide selected from those
according to Formula 1 whereby R.sub.1.dbd.CH.sub.3,
R.sub.2.dbd.CH.sub.3, n=8-10 and m=5-8;
[0092] c) about 1 wt % to about 7 wt % fatty acids selected from
those containing saturated and unsaturated chains of between 16 and
22 carbons;
[0093] d) about 8 wt % to about 14 wt % of a mixture of amine
compounds, consisting of those described by Formula 2 whereby
R.sub.1.dbd.H or --CH.sub.2CH.sub.2OH, R.sub.2.dbd.H, or
--CH.sub.2CH.sub.2OH, and R.sub.3.dbd.--CH.sub.2CH.sub.2OH, or
--C.sub.3H.sub.6OH;
[0094] e) about 5 wt % to about 9 wt % of an amine salt of boric
acid according to the structure shown in Formula 3:
B(O.sup.- HN.sup.+(CH.sub.2CH.sub.2OH).sub.n).sub.m Formula 3:
[0095] whereby n=m=3;
[0096] f) about 40 wt % to about 55 wt % of a naphthenic-based
mineral oil with an ambient pressure viscosity of between 15-30 cSt
at 40 degrees centigrade; and
[0097] g) about 4 wt % to about 15 wt % of a mixture of nonionic
and anionic emulsifiers selected from those commonly known in the
art and typically used in water based metalworking fluids.
[0098] Such fluid compositions, when blended in an amount of about
4 wt % to about 15 wt % in water, and utilized in the machining of
iron such as compacted graphite iron, produce a noticeable decrease
in the rate of tool wear which occurs as well as a noticeable
enhancement in the quality of the part machined.
[0099] Fluid F was tested in the drilling and reaming of Grade 450
CGI at a concentration of 8%. This fluid composition was tested
along with and compared to the performance of a conventional
machining fluid utilized for cast iron machining (including CGI),
Fluid G. Fluid G is similar to Fluid F in composition but does not
contain the sulfur based additive.
[0100] Along with CGI, these two fluids were also tested in the
drilling and reaming of a common Class 40 gray cast iron. This
testing was performed not only to demonstrate the utility of the
fluid compositions described in this invention, but also the
inherent difficulty associated with the machining of CGI relative
to gray cast iron.
[0101] The torque (tangential forces) measured during drilling
provides a useful indication of the friction in the cutting zone
and the lubrication provided by the metalworking fluid. The change
in the torque measured as drilling continues reflects the changes
(wear) occurring on the tools cutting edge as drilling continues.
In examining the results shown in FIG. 5, the lower machinability
and greater challenge inherent in the machining of compacted
graphite iron relative to a standard Class 40 gray cast iron is
clearly seen.
[0102] The results also demonstrate that the use of a fluid
according to embodiments of the present invention (Fluid F)
provides significant enhancement in the machining process with much
reduced cutting forces. This effectiveness of the preferred
composition is also seen in the tool wear measured following
drilling. FIG. 6 shows the tool wear obtained on the drills used.
As seen and consistent with the cutting forces measured, while
significantly higher wear occurs in compacted graphite iron
machining relative to gray cast iron machining, the use of Fluid F
enables for the effective reduction of wear on the tool cutting
edge.
[0103] Although a reaming operation, which is performed at lower
cutting speeds with less metal removal is considered to be a less
severe operation to that of drilling, there may still be
significant performance improvement obtained through use of a fluid
composition according to embodiments of the present invention.
Following drilling, the holes were reamed using a six fluted solid
carbide reamer. The surface finish measured over the one hundred
thirty holes reamed are shown in FIG. 7. It is seen that with use
of the conventional ferrous machining fluid (Fluid G) rougher
reamed hole surfaces are obtained very quickly, the use of Fluid F
yields a significant improvement in the reamed hole surface
roughness obtained.
Example 4
[0104] Boring of engine cylinders is one of the more critical
operations in engine production, requiring high quality surfaces to
be produced at relatively high cutting speeds. It is at such
elevated cutting speeds (250-700 m/min), consistent with those used
in many current high speed transfer lines, where the machinability
differences between compacted graphite iron and conventional gray
cast irons may be most pronounced. Previous studies have reported
insert wear rates to be 20-30 times greater in the continuous
cutting of compacted graphite iron relative to that obtained in the
machining of gray cast iron under equivalent conditions.
[0105] In this example, a standard conventional ferrous machining
fluid (Fluid B) along with a fluid described according to
embodiments of the current invention were assessed in a turning
operation utilized to simulate the continuous cutting conditions
which occur during engine cylinder boring. Fluid A, useful for the
improved machining of compacted graphite iron, was prepared
according to embodiments of the present invention having:
[0106] a) about 5 wt % to about 10 wt % ester lubricant;
[0107] b) about 3 wt % to about 7 wt % of a sulfur additive;
[0108] c) 8 wt % to about 16 wt % mineral oil; and
[0109] d) the balance having amines, boric acid, fatty acids, and
emulsifiers.
[0110] Fluid A was tested at a concentration of 9%. The machining
conditions are as follows: [0111] Carbide Grade KC-9120 cutting
insert with 5.degree. radial and 5.degree. axial angle [0112]
Speed=250 m/min, f=0.3 mm-rev, Ap=0.2 mm
Measured Parameter--Insert Wear
[0113] In assessing the impact on the tool wear which occurs, using
the conventional ferrous machining fluid (Fluid B), machining
continued for 10.75 Km of cutting distance before severe wear and
failure of the tool was reached. Using the fluid composition
described in the current invention (Fluid A), using identical
machining conditions, machining continued for 14 Km of cutting
distance before insert failure was reached. Thus under the high
speed cutting conditions a 30% reduction in insert wear was
obtained using the fluid described in the current invention.
* * * * *