U.S. patent application number 09/891033 was filed with the patent office on 2002-12-26 for geometrically articulated amorphous metal alloys, processes for their production and articles formed therefrom.
Invention is credited to Decristofaro, Nicholas J., Liebermann, Howard H., Orloff, Glennis J..
Application Number | 20020195178 09/891033 |
Document ID | / |
Family ID | 25397514 |
Filed Date | 2002-12-26 |
United States Patent
Application |
20020195178 |
Kind Code |
A1 |
Liebermann, Howard H. ; et
al. |
December 26, 2002 |
Geometrically articulated amorphous metal alloys, processes for
their production and articles formed therefrom
Abstract
The invention relates to a geometrically articulated amorphous
metal alloy articles and processes for their production.
Inventors: |
Liebermann, Howard H.;
(Succasunna, NJ) ; Decristofaro, Nicholas J.;
(Chatham, NJ) ; Orloff, Glennis J.; (Woodbridge,
CT) |
Correspondence
Address: |
Roger H Criss
Honeywell International Incorporated Law Dept.
101 Columbia Road
Morristown
NJ
07962
US
|
Family ID: |
25397514 |
Appl. No.: |
09/891033 |
Filed: |
June 25, 2001 |
Current U.S.
Class: |
148/561 ;
148/403 |
Current CPC
Class: |
C22C 45/04 20130101;
B21D 26/14 20130101; H01F 1/153 20130101; H01F 1/15341
20130101 |
Class at
Publication: |
148/561 ;
148/403 |
International
Class: |
C22C 045/00 |
Claims
What is claimed is:
1. An amorphous metal alloy article having an articulated
topographical definition.
2. An amorphous metal alloy article according to claim 1 which
comprises a plurality of articulated topographical definitions.
3. An amorphous metal alloy article according to claim 1 which
comprises a plurality of geometrically repeating articulated
topographical definitions.
4. An amorphous metal alloy article having an articulated
topographical definition wherein the amorphous metal alloy has a
composition which may be represented by the
formula:M.sub.kY.sub.pwherein: M is a metal selected from one or
more of the group consisting of Fe, Ni, Co, V and Cr; Y represents
one or more elements from the group consisting of P, B and C; k
represents atomic percent, and has a value of from about 70-85; p
represents atomic percent, and has a value of about 15-30;
5. An amorphous metal alloy article having an articulated
topographical definition wherein the amorphous metal alloy has a
composition which may be represented by the
formula:M.sub.aY.sub.bZ.sub.cwherein: M is a metal selected from
one or more of the group consisting of Fe, Ni, Co, V and Cr; Y
represents one or more elements from the group consisting of P, B
and C; Z is one or more elements selected from the group Al, Si,
Sn, Ge, In, Sb or Be; a represents atomic percent and has a value
of from about 60-90; b represents atomic percent and has a value of
from about 10-30; c represents atomic percent and has a value of
from about 0.1-15; and a+b+c=100.
6. An abrasive article which comprises the amorphous metal alloy
article having an articulated topographical definition according to
claim 1.
7. An abrasive article which comprises the amorphous metal alloy
article having a plurality of an articulated topographical
definition according to claim 2.
8. A cutting article which comprises the amorphous metal alloy
article having an articulated topographical definition according to
claim 1.
9. A cutting article which comprises the amorphous metal alloy
article having a plurality of an articulated topographical
definition according to claim 2.
10. A amorphous metal alloy article having an articulated
topographical definition according to claim 2.
11. An article which comprises a plurality of self-nesting
amorphous metal alloy articles.
12. A wound transformer core according to claim 2.
13. A stacked transformer core according to claim 2.
14. A process for the manufacture of an amorphous metal alloy
article having an articulated topographical definition which
comprises the steps of: heating the amorphous metal alloy article
to an elevated temperature and subsequently stamping or otherwise
deforming the heated amorphous metal alloy article in a die.
15. The process according to claim 14 wherein the die is
preheated.
16. The process according to claim 14 wherein the die is a roller
die or a stamping die.
17. The process according to claim 14 wherein at last part of the
articulated topographical definitions are selectively
crystallized.
18. The process according to claim 14 wherein at last part of the
articulated topographical definitions are ground to remove a part
of the articulated topographical definitions.
19. The process according to claim 14 wherein an abrasive material
is adhered to at least the articulated topographical definitions of
the amorphous metal alloy article.
Description
BACKGROUND OF THE INVENTION
[0001] The present invention relates to the amorphous metal alloys
having an articulated three-dimensional ("3-D") geometric texture
therein, as well as a process for producing the same.
[0002] Amorphous metal alloys (also often referred to as "amorphous
metal alloys", "glassy metals" or "metallic glasses") typically
lack any substantial long range atomic order. These amorphous metal
alloys are characterized by X-ray diffraction patterns consisting
of diffuse (broad) intensity maxima, qualitatively similar to the
diffraction patterns observed for liquids or for inorganic oxide
glasses. However, upon heating to a sufficiently high temperature,
they begin to crystallize with the evolution of the heat of
crystallization; correspondingly, the X-ray diffraction pattern
thereby begins to change from that observed for amorphous to that
observed for crystalline materials. Consequently, amorphous metal
alloys are in a metastable state. This special metastable amorphous
state of the alloys confers unique mechanical and physical
properties to the alloy.
[0003] Amorphous metal alloys generally possess physical properties
such as hardness and strength exceeding those of their crystalline
counterparts. Since amorphous metal alloys, unlike crystalline
alloys, have no long-range order in their atomic structure, the
directionality of physical and magnetic properties normally
associated with a crystalline periodic (crystalline) atomic
structure is absent. Also, unlike conventional alloys, amorphous
metal alloys are extremely homogeneous, being devoid of
compositional heterogeneity, inclusions, and various other
microstructural defects, making them less subject to the
deleterious effects of these potential stress concentrators.
[0004] Amorphous metal alloys can be made by various techniques.
Electroplating, vapor deposition, and sputtering are all methods by
which material is deposited on an atom-by-atom basis. Under
appropriate conditions, the atoms are "frozen" in-situ on contact
with a substrate surface and normally cannot diffuse into the lower
energy atomic configurations associated with that of a stable,
periodic crystalline lattice. The resulting metastable structure
can be a non-crystalline (glassy) one. Such process methods,
however, are not economically feasible for producing large
commercial quantities of amorphous metal alloys.
[0005] Another method for producing amorphous metal alloys is by
rapidly cooling from the melt. Two major conditions apply in
achieving a glassy structure by this method. First the composition
selected should have a high glass transition temperature, T.sub.g,
and a low melting temperature, T.sub.m. The glass transition
temperature is that above which substantial atomic motion begins to
occur. The melting temperature is that above which there is
complete liquefication of a material. Specifically, the
T.sub.g/T.sub.m ratio should be as large as possible. Second, the
liquid should be cooled as rapidly as possible from a temperature
above T.sub.m to a temperature below T.sub.g. In practice, it is
generally found that the cooling rate for a melt-quenching method
must be great enough (approximately 1 million degrees/second) to
circumvent crystallization which would otherwise occur. Even at the
high cooling rates typically used, only alloys with certain
compositions can be melt-quenched into amorphous metal alloys. One
class of such amorphous metal alloys consists of "glass-forming"
metalloid atoms, eg. phosphorus, boron, silicon, and carbon as
required alloy additions, usually in the 10 to 25 atomic percent
range, in combination with late transition metal elements such as
iron, nickel, cobalt, and chromium. Another class of metallic
glasses consists of a mixture of early and late transition
atoms.
[0006] When subjected to sufficiently high mechanical stress,
amorphous metal alloys undergo heterogeneous plastic deformation
through the formation of highly localized shear bands, at
temperatures well below the glass transition temperature, T.sub.g.
This type of heterogeneous plastic deformation is similar to that
of conventional crystalline alloys. At such low temperatures,
amorphous metal alloys exhibit high strength and high modulus, and
exhibit a fracture stress that is only marginally greater than the
yield stress. This results in only a small amount of extension on
tension before failure. In contrast, the mode of plastic
deformation near and above T.sub.g is one in which the macroscopic
strain in the specimen results from homogeneous deformation by
viscous-like flow throughout the entire sample volume.
[0007] Discussions of the deformation behavior of amorphous metal
alloys as a function of temperature appears not infrequently in the
technical literature, e.g., Japanese Patent No. 53-57170 of May 24,
1978 to Masumoto. In this patent, Masumoto describes the
temperature regime in which increased "fabricability" occurs.
Masumoto also proposes that a forming process such as rolling,
punching, pressing, pulling out, and bending will be viable in that
temperature regime. Patterson et al. in Rapidly Quenched Metals
III, vol.2 (1978) describes the ability to hot form amorphous metal
alloy ribbon into a cup like shape when deformed at elevated
temperature. The authors teach an appreciation for the trade-off
between hot forming temperature and time, and the risk of amorphous
metal alloy crystallization when process temperature is too
high.
DESCRIPTION OF THE DRAWINGS
[0008] FIG. 1 is a graph which shows the time-temperature
dependence for complete stress relaxation in an
Fe.sub.80B.sub.11Si.sub.9 amorphous metal alloy.
[0009] FIG. 2a is a top view of an amorphous metal alloy strip
having a geometrically repeating articulated topographical
definition.
[0010] FIG. 2b is a side view of the amorphous metal alloy strip
according to FIG. 2a.
[0011] FIG. 3a is a depiction of a further amorphous metal alloy
strip having a second articulated topographical definition, which
is not geometrically repeating.
[0012] FIG. 3b is a side view of the amorphous metal alloy strip
according to FIG 3a.
[0013] FIG. 4 is a depiction of an embodiment of a cutting article
produced from an amorphous metal alloy strip having a geometrically
repeating articulated topographical definition.
SUMMARY OF THE INVENTION
[0014] In one aspect the present invention there are provided
amorphous metal alloy articles having an articulated topographical
definition.
[0015] In another aspect of the invention there are provided
methods for the production of amorphous metal alloy articles having
an articulated topographical definition.
[0016] In a still further aspect of the invention there are
provided abrasive articles formed utilizing amorphous metal alloy
articles having articulated topographical definitions.
[0017] In a yet further aspect of the invention there are provided
methods for the production of abrasive articles formed of amorphous
metal alloy articles having an articulated topographical
definition.
[0018] In a further aspect of the invention there are provided
shaving articles formed utilizing amorphous metal alloy articles
having articulated topographical definitions, as well as methods
for their production.
[0019] In another aspect of the invention there are provided
self-nesting amorphous metal alloy articles having an articulated
topographical definition.
[0020] In a yet further aspect of the invention there are provided
methods for the production of self-nesting amorphous metal alloy
articles having an articulated topographical definition.
[0021] These and other aspects of the invention will become more
apparent from the following detailed description of the
invention.
DETAILED DESCRIPTION AND DESCRIPTION OF PREFERRED EMBODIMENTS
[0022] The present invention provides novel amorphous metal alloy
articles having an articulated topographical definition as well as
processes for their production. Such articulated topographical
definitions are created by the application of selected forces to a
generally planar ("2-dimensonal") amorphous metal foil or ribbon in
order to introduce permanent deformations therein so to produce a
non-planar ("3-dimensional") amorphous metal foil or ribbon which
includes a geometric pattern, texture, profile or other feature,
collectively referred to as "articulated topographical
definitions". With respect to such articulated topographical
definitions, it is required only that there be introduced permanent
deformations which will distort or distend the generally planar
amorphous metal foil or ribbon, as is usually applied in an "as
cast" form, so to provide a permanent non-planar three-dimensional
profile. Such may be likened to indentations. At the very minimum,
a single articulated topographical definition may be provided but
more advantageously a plurality of geometrically repeating
articulated topographical definitions. Such geometrically repeating
articulated topographical definitions can be any shape or
configuration which provide a regularly repeating pattern of
articulated topographical definitions and ideally are those which
show an interlock between their individual patterns. For example,
pyramidal shapes, square shapes, circular shapes, and hexagonal
shapes can all be used without limitation. Ideally, those which
provide close packing at their base portions, especially hexagonal
shape, pyramidal shape, square shapes, rectangular shapes,
triangular shapes, etc. are to be generally preferred as the
maximum amount of peaks per unit surface area of the articles can
be produced.
[0023] Successful practice of the present invention relies upon the
exploitation of stress relaxation characteristics of the amorphous
metal alloy. Stress relaxation in amorphous metal alloys is
intimately linked to atomic structure relaxation, in which the
"free volume" which is quenched-in during production is gradually
dissipated while a test piece undergoes a shape change, such as the
development of geometrically articulated including patterns,
textures or other definitions. The greater the free volume content
of an amorphous metal alloy, the greater its ability to take on
geometric definition during processing. FIG. 1 shows the
time-temperature dependence of stress relaxation for an amorphous
metal alloy having nominal composition Fe.sub.80B.sub.11Si.sub.-
9.
[0024] It is to be understood that any amorphous metal alloy
composition which may be provided with at least one but preferably
a plurality of articulated topographical definitions may be
practiced and is considered to be within the scope of the present
inventive teaching. By way of non-limiting example, the
compositions of amorphous metal alloys which may be subjected to
the process according to the invention include those which are
primarily composed of Fe, Ni, Cr, Co and V, to which optionally,
but in some cases desirably are added small amounts, i.e., from 0.1
to 15 atomic percent, but preferably from 0.5 to 6 atomic percent
of certain elements such as Al, Si, Sn, Sb, Ge, In, or Be.
Frequently the addition of these latter recited elements in the
amounts discussed improved the glass forming characteristics of the
amorphous metal alloys, viz., the amorphous state is more readily
obtained and is often more thermally stable. Particularly useful
amorphous metal alloys are those which may be represented by either
the formula:
M.sub.kY.sub.p
[0025] wherein:
[0026] M is a metal selected from one or more of the group
consisting of Fe, Ni, Co, V and Cr;
[0027] Y represents one or more elements from the group consisting
of P, B and C;
[0028] k represents atomic percent, and has a value of from about
70-85;
[0029] p represents atomic percent, and has a value of about 15-30;
as well as by the formula:
M.sub.aY.sub.bZ.sub.c
[0030] wherein:
[0031] M, Y are as defined above,
[0032] Z is one or more elements selected from the group Al, Si,
Sn, Ge, In, Sb or Be;
[0033] a represents atomic percent and has a value of from about
60-90;
[0034] b represents atomic percent and has a value of from about
10-30;
[0035] c represents atomic percent and has a value of from about
0.1-15;
[0036] and, a+b+c=100.
[0037] It is to be understood however that these exemplary
amorphous metal alloy compositions are provided by way of
illustration and not by way of limitation as it is contemplated
that virtually all compositions of amorphous metal alloys which may
successfully be formed according to the inventive process taught
herein may enjoy the benefits of the invention.
[0038] Turning to FIGS. 2a and 2b, there are depicted one example
of an amorphous metal foil strip or tape (20) having a plurality of
geometrically repeating articulated topographical definitions (24),
where each of the articulated topographical definitions has a
hexagonal base (26) and which tapers to a plateau (28) at the peak
of each articulated topographical definitions (24). As a review of
this Figure will reveal, close packing of the individual
articulated topographical definitions are possible due to the
interlocking nature of the bases of each. As can be seen, the
hexagonal geometry of these bases provides such close packing.
[0039] With reference to FIGS. 2a and 2b, it is also to be
understood that it is clear that each of the articulated
topographical definitions according to the invention also have
geometric dimensions which are to be considered. For example, each
articulated topographical definition has a base dimension, which
includes a base area (21) within the plane of the amorphous metal
foil strip or tape (20). Naturally, it is to be understood that
where a maximum number of articulated topographical definitions are
to be introduced to an amorphous metal ribbon, that the respective
size of each single articulated topographical definition, and their
base areas should be small. The converse is also true. For example,
with reference to the generally hexagonal articulated topographical
definitions shown on FIGS. 2a and 2b three generally hexagonal
articulated topographical definitions are present per row. This is
depicted on FIG. 2a with regard to reference lines "a" and "b" each
of which bisects the three generally hexagonal articulated
topographical definitions, three (a', a", a'") on reference line
"a" and three (b', b", b'") on reference line "b". A denser packing
of articulated topographical definitions could easily have been
introduced into the amorphous metal ribbon by providing generally
hexagonal articulated topographical definitions having smaller
individual base areas. It is also contemplated that articulated
topographical definitions of different shapes and configurations
could be used as well, and that such articulated topographical
definitions need not have abutting bases as the layout of generally
hexagonal articulated topographical definitions shown in FIG.
2a.
[0040] FIGS. 3a and 3b illustrate an alternative embodiment of an
amorphous metal alloy ribbon (30) which has introduced therein a
series of individual articulated topographical definitions (34)
which are not closely packed, but which form individual discrete
articulated topographical definitions. As can be seen from FIG. 3a,
each of these individual articulated topographical definitions (34)
are randomly positioned within the amorphous metal alloy strip
depicted, and indeed, these articulated topographical definitions
are of different sizes. Namely, while each of the depicted
articulated topographical definitions is an equilateral triangle in
its base, and tapers to a point (38) (intended to be extending
outward of the paper, and depicted by a point), the non-packed
arrangement of these articulated topographical definitions, as well
as their different dimensions illustrates the concept that various
configurations for articulated topographical definitions can be
used and still enjoy the benefits of the invention. Specifically,
FIG. 3 also illustrates the concept that articulated topographical
definitions of different geometries and/or relative dimensions,
including differing heights, can also be provided to a single
amorphous metal alloy foil according to the present inventive
principles.
[0041] Throughout the description of the various embodiments of the
invention, it is to be understood that the geometrical form
described with reference to each of the figures is intended by way
of illustration and not by way of limitation. These articulated
topographical definitions can be of any form including polygonal or
irregular polygonal forms. Thus, it is to be understood that
different articulated topographical definitions other than those
described with reference to a particular figure of example may be
substituted for the particular articulated topographical
definitions discussed or depicted herein.
[0042] The articulated topographical definitions are conveniently
provided to the amorphous metal alloy by use of a mechanical means
such as a roller die or a stamping die. What is referred to as a
roller die is generally intended to mean two rollers having upon
their surfaces a series of mating configurations which are intended
to impart upon a body, such as an amorphous metal alloy strip or
foil passing between the nip of these roller dies a series of
articulated topographical definitions. Similarly, by a stamping die
is meant a pair of dies having a mating surfaces, which are also
intended to impart articulated topographical definitions to a
material, particularly the amorphous metal foils or strips
described herein which are placed in between these two dies. Both
embodiments of dies, either the roller or stamping die can be used
for the compression of the amorphous metal alloy for the strips
take place in order to impart permanent deformation to the planar,
two-dimensional foil or strip so as to impart permanent, non-planar
three-dimensional profiles.
[0043] With regard to the appropriate operating conditions in order
to provide such permanent articulated topographical definition, it
would be recognized that the specific conditions will in great
degree be dependent upon the thickness, as well as the chemical
nature of the amorphous metal alloy being treated. Ideally, it is
intended that the selection of an appropriate deformation
temperature is to be based on the considerations of minimizing or
eliminating crystallization during the stamping step, and ideally
also based on the considerations of minimizing or eliminating
embrittlement of the amorphous metal foil during this stamping
step. As such, these specific conditions can be determined by
routine trial steps which can be carried out by the skilled
practitioner, and specific embodiments based on a specific
amorphous metal alloy are described in more detail below. It is
believed that based upon the specific examples, one of appropriate
skill in the art may determine the appropriate stamping conditions
without the exercise of undue experimentation.
[0044] The present invention can be practiced in any number of
variations. The most direct means is to heat the amorphous metal
alloy foil or strip to an elevated temperature and subsequently
stamp or otherwise deform said amorphous metal alloy foil or strip
utilizing an appropriate die. Alternately, the amorphous metal
alloy foil or strip may be provided to a preheated die which is at
a sufficiently elevated temperature such that during the stamping
process the amorphous metal alloy body will be rapidly heated to an
appropriate temperature. In a still further variation, both the
amorphous metal alloy foil or strip and the stamping die(s) are
heated to an elevated temperature prior to or during the stamping
process.
[0045] With regard to the temperature at which the stamping process
occurs, the applicant has discovered that while a higher elevated
temperature typically results in a shorter residence time in the
die, or alternately less pressure required of the die such is not
particularly to be desired where there is a significant risk of
crystallization and/or of embrittlement of the amorphous metal
alloy foil or strip. Rather, it is beneficial to increase the
residence time of the metal alloy foil or strip in the die while
concurrently reducing the temperature of the stamping operation so
that the risk or degree of crystallization is minimized. Such
increased residence time also addresses the limitations of thermal
diffusivity and ensures that the temperature throughout the
thickness of the amorphous metal alloy foil or strip is
substantially uniform.
[0046] The invention also provides abrasive articles formed of
amorphous metal alloy articles having articulated topographical
definitions, as well as process for making the same. According to
this embodiment, articulated topographical definitions are provided
to an amorphous metal alloy or strip as described previously, and
subsequently the alloys or strips are further treated to impart
abrasive characteristics thereto.
[0047] In one aspect, an abrasive medium such as any number of
organic oxides or carbides are provided to at least one surface,
and desirably to the region of the peaks of the articulated
topographical definitions in the alloys or strips. In this manner,
the amorphous metal alloy or strip which is known to be
particularly hard provides a very useful substrate upon which the
abrasive materials are applied. In an alternative, subsequent to
the provision of the articulated topographical definitions to the
amorphous metal alloy or strip portions of the amorphous metal
alloy or strips and, in particular, portions of the articulated
topographical definition at or near the peak of said articulated
topographical definitions are partially crystallized. Such
selective crystallization would be expected to cause precipitation
of very hard intermetallic phases of the composition of the
amorphous metal alloy. Such hard intermetallic phases are very
effective as an abrasive medium and are also very effective in
providing cutting edges to articles formed of amorphous metal
alloys. This selective crystallization can take place by any of a
number of means, and according to one particular method, it is
contemplated that the use of a laser whose tight focus beam can be
directed at or in the region of the peaks of the articulated
topographical definitions can be used to provide such selective
crystallization. Alternatively or in conjunction with the selective
crystallization of the tips of the articulated definitions in the
amorphous metal alloys of the present invention, hard abrasive
particles may be adhered or otherwise associated with the
articulated amorphous metal alloy articles. Such adhesion or
association may for example be achieved by adhesive bonding, plasma
spraying, impact welding as well as other techniques know to the
art but not elucidated here. Other methods not described herein,
but which are believed to be useful in providing such selective
crystallization are also contemplated to be useful and within the
scope of the present invention.
[0048] In a yet further embodiment, an abrasive article according
to the invention is produced by providing cutting edges to the
articulated topographical definitions of the amorphous metal alloy
strips produced according to the method described generally above.
According to this further embodiment, portions of the articulated
topographical definitions, and especially the peaks of the
articulated topographical definitions are removed subsequent to
their formation. These are literally "lopped off" exposing sharp
cutting edges of the individual articulated topographical
definitions. Such an operation can be done, for example, by
grinding of portions of the articulated topographical definitions,
or by any other mechanical operation, as well as by non-mechanical
operations. It is only required that a portion of the articulated
portions of the amorphous metal alloys be provided with a cutting
edge. In a conventional a grinding operation, sharpening of the
individual cutting edges of the articulated topographical
definitions is also simultaneously achieved and thus, is amongst
the preferred methods of production. Such an embodiment is
illustrated in FIG. 4 which depicts in side view a cutting article
according to the invention which includes an amorphous metal alloy
strip (40) having a plurality of frustoconical articulated
topographical definitions extending outwardly from a top face. The
cutting edge (48) of each of these frustoconical articulated
topographical definitions (44) is formed by grinding the peaks of
articulated topographical definitions having a conical form so to
remove the peaks thereof, resulting in the these frustoconical
articulated topographical definitions (44). According to this
particular embodiment, such a cutting article provides several
unexpected and significant technical advantages over other cutting
devices generally known in the art. The high hardness of the
amorphous metal alloys are expected to provide longer lasting keen
cutting edges which provide a longer service life to a cutting
article made therefrom. Further, where the articulated
topographical definitions have their peaks "lopped off" such as in
a grinding operation, the resulting cutting edges are
non-directional, that is to say that unlike a straight edge cutting
article (such as a straight knife blade), cutting occurs upon any
directional movement of the cutting articles described according to
the present invention. Thus, orientation of cutting direction
relative to a work piece is not a concern as in any direction, the
cutting tool disposes a sharp edge for cutting.
[0049] It is to be understood that other configurations are also
considered to fall within the scope of such cutting articles
according to the invention including geometrically articulated
amorphous metal alloys having circular, rounded, slotted,
geometric, such as square or rectangular, and irregularly shaped
features as well as any combination of these features which can be
formed. The contour of the cutting edge formed from geometrically
articulated amorphous metal alloys are also readily adjustable. The
cutting edges can be straight, beveled or shaped.
[0050] It is contemplated that other techniques than those
discussed previously, and in particular techniques which do not
utilize a grinding step may also be used in the manufacture of such
cutting tools as well. Such techniques include, by way of
non-limiting example, formed by one or more of the known processes
of electrochemical machining (ECM), electrical discharge machining
(EDM), electrolytic machining, laser-beam machining (LBM),
electron-beam machining (EBM), photochemical machining (PCM), or
ultrasonic machining (USM). Edge formation may be followed with
supplemental metallic or non-metallic coatings and procedures
standard in the art such as coating with polytetrafluoroethylene
(Teflon) or other lubricious materials, followed by heat
treatments. EDM process involves the use of an EDM tool which is
fed into the area to be cut. A dielectric fluid is placed into the
area to be cut and rapid, repetitive spark discharges are fed
between the tool and the articulated amorphous metal alloy to
remove conductive material and consequently produce an aperture.
Multiple tools may be employed to produce the multiple desired
apertures. The EDM process is especially useful in situations where
the cutting will be irregular and is capable of producing up to
about 200 simultaneous holes. The ECM process cuts the articulated
amorphous metal alloys via anodic dissolution in a rapidly flowing
electrolyte between the steel and the shaped electrode. As with
EDM, ECM may be employed to simultaneously produce multiple
apertures and is capable of producing up to about 100 simultaneous
holes.
[0051] Additionally, it is also contemplated that wherein the
amorphous metal cutting article is mounted upon a suitable
substrate, ideally one which is non-solid but which provides a more
rigid support framework (such as a grid, peripheral or edge frame,
etc.) than the articulated amorphous metal itself. Ideally, in use
any material removed during a cutting operation falls through the
interior of each of the individual articulated topographical
definitions and can be readily removed away from the surface or
object being cut. This is significant, as this ensures that the
cutting articles made according to the invention are non-clogging,
thus further extending the useful service life of said cutting
article. By way of non-limiting example cutting devices include
razors for use in personal care products i.e., shaving razors.
Further cutting devices include other tools such as planes, files,
rasps, Surform.RTM.-type tools, sanding and abrasive tools,
grinding wheels wherein a strip of the geometrically articulated
amorphous metal alloys are mounted on the periphery of a wheel, as
well as other tools not particularly elucidated here.
[0052] The structure and design of the cutting edge aperture in
such cutting articles is essentially unlimited using
non-traditional machining techniques. Circular, rounded, slotted,
geometric, such as square or rectangular, and irregularly shaped
features as well as any combination of these features can be formed
and contoured. The contour of the cutting edge is also readily
adjustable. The edge can be straight, beveled or shaped. Both
lateral and longitudinal structures are readily formed using
electrochemical machining, electrical discharge machining,
electrolytic machining, laser-beam machining, electron beam
machining, photochemical machining, ultrasonic machining, and other
alternative machining techniques in a single step, in contrast to
traditional grinding techniques which require extensive part
manipulation and may not even be capable of producing these
features. Various techniques may be utilized including known art
grinding operations including those discussed in U.S. Pat. No.
5,604,983 to Simms et al, U.S. Pat. No. 5,490,329 and to Chylinski,
U.S. Pat. No. 4,483,068. Particularly useful and preferred
techniques which are useful include those which do not require a
grinding operation in order to produce a sharpened edge including
the methods described in U.S. Pat. No. 5,983,756 to Orloff, the
contents of which are ire incorporated herein by reference.
[0053] In another aspect of the invention there are provided
self-nesting articles formed of amorphous metal alloy articles
having an articulated topographical definition, as well as methods
for making the same.
[0054] A particularly advantageous feature attained by the
introduction of these articulated topographical definitions to an
amorphous metal foil or tape is that this facilitates the oriented
stacking of multiple foils or strips. Such is particularly useful
in the fabrication of any of a variety of devices which require
built-up layers or stacks of amorphous metal foils. For example, in
the construction of transformers wherein a large number, typically
in the excess of several hundreds of amorphous metal foils are
required in order to produce a round core, it has frequently been
problematic in the actual handling steps required to the
manufacture of this core. The smooth, slippery surface of the
amorphous metal foils typically require the utilization of a frame,
jig, or other holding means (including epoxy glues, and the like)
in order to maintain the desired geometric configuration of these
layers of amorphous metal foils or strips. Utilizing, however, the
articulated topographical definitions which are introduced to the
foil or strips, much of these technical problems associated with
fabrication are eliminated. This is due to the fact that wherein a
regularly repeating pattern is introduced, these provide nesting
between the various layers. This nesting provides physical
retention and interlocking between the individual layers, and
removes or diminishes the necessity for any holding means,
particularly chemical holding means such as glues, epoxies or the
like. Such interlocking between successive layers also provides for
enhanced degree of rigidly in the finely assembled construction or
assembly.
[0055] While described with reference to wound cores, such as used
in transformers, it is also contemplated that the beneficial
features of stacked and interlocking amorphous metal foils or
strips can be utilized in stacked cores which are also known in the
transformer art.
[0056] The benefits of the invention described herein may also be
enjoyed in a wide variety of other applications, although these
applications are not necessarily elucidated here.
EXAMPLES
Example 1
[0057] Input stock for development of the present invention was
made by planar flow casting 25.4 mm wide
Ni.sub.68Cr.sub.7Fe.sub.3B.sub.14Si.sub.- 8 amorphous metal alloy
ribbon. One cast was used to make ribbon having thickness 40 .mu.m
while another cast was used to make ribbon of thickness 90 .mu.m.
An Instron.RTM. tensile testing unit was equipped with an oven to
enable high temperature testing/operations. Both load and
temperature were computer controlled, following instructions
programmed. A male/female axially loaded die assembly was
constructed and used to attempt making articulated pyramidal
impressions in pieces of the each of the ribbon types using various
process parameters.
[0058] Crystallization temperature for the
Ni.sub.68Cr.sub.7Fe.sub.3B.sub.- 14Si.sub.8 amorphous metal alloy
is 470.degree. C., as determined by differential scanning
calorimetry. Process temperatures between 325.degree. C. and
500.degree. C. were investigated. Process loads ranged from 2.22 to
6.67 kN, while process times were varied between 15 and 60 seconds.
Process temperature was found to be the single most important
variable in terms of enabling 3-D geometric feature formation at
all. Process force was demonstrated to be the second most important
variable, functioning primarily to define details of 3-D geometric
feature articulation. It was found that process time is not an
important variable for the range of process variables used.
[0059] The onset of 3-D geometric feature articulation occurs at
higher temperature/force/time for thicker ribbon than for thinner
ribbon. For example, this onset occurred when exceeding 400.degree.
C., 3.56 kN, 15 seconds for the 40 .mu.m thick ribbon in comparison
with having to exceed 400.degree. C., 6.67 kN, 15 seconds for the
90 .mu.m thick ribbon. Noticeable ribbon brittleness and warping
were observed when processing at 500.degree. C., even though 3-D
geometric feature articulation was very good.
Example 2
[0060] A 15 cm length of 40 .mu.m thick
Ni.sub.68Cr.sub.7Fe.sub.3B.sub.14S- i.sub.8 amorphous metal alloy
strip was compressed using 1.78 kN force for 30 seconds in a die
situated in an oven at 325.degree. C. The resultant 3-D geometric
pattern was ill-defined and, in fact, barely visible.
Example 3
[0061] A 15 cm length of 40 .mu.m thick
Ni.sub.68Cr.sub.7Fe.sub.3B.sub.14S- i.sub.8 amorphous metal alloy
strip was compressed using 3.56 kN force for 60 seconds in a die
situated in an oven at 400.degree. C. The resultant 3-D geometric
pattern was very well articulated in every detail of the die.
Example 4
[0062] A 15 cm length of 90 .mu.m thick
Ni.sub.68Cr.sub.7Fe.sub.3B.sub.14S- i.sub.8 amorphous metal alloy
strip was compressed using 3.56 kN force for 60 seconds in a die
situated in an oven at 375.degree. C. The resultant 3-D geometric
pattern was not well defined.
Example 5
[0063] A 15 cm length of 90 .mu.m thick
Ni.sub.68Cr.sub.7Fe.sub.3B.sub.14S- i.sub.8 amorphous metal alloy
strip was compressed using 6.67 kN force for 15 seconds in a die
situated in an oven at 425.degree. C. The resultant 3-D geometric
pattern was very well articulated in every detail of the die.
[0064] While the invention is susceptible of various modifications
and alternative forms, it is to be understood that specific
embodiments thereof have been shown by way of example in the
drawings which are not intended to limit the invention to the
particular forms disclosed; on the contrary the intention is to
cover all modifications, equivalents and alternatives falling
within the scope and spirit of the invention as expressed in the
appended claims.
* * * * *