U.S. patent application number 15/232601 was filed with the patent office on 2017-02-09 for hard coating film having anti-adhesion property to soft metal.
This patent application is currently assigned to KABUSHIKI KAISHA KOBE SEIKO SHO (KOBE STEEL, LTD.). The applicant listed for this patent is KABUSHIKI KAISHA KOBE SEIKO SHO (KOBE STEEL, LTD.). Invention is credited to Kenji YAMAMOTO.
Application Number | 20170036258 15/232601 |
Document ID | / |
Family ID | 51261936 |
Filed Date | 2017-02-09 |
United States Patent
Application |
20170036258 |
Kind Code |
A1 |
YAMAMOTO; Kenji |
February 9, 2017 |
HARD COATING FILM HAVING ANTI-ADHESION PROPERTY TO SOFT METAL
Abstract
The invention provides a hard coating film insusceptible to
adhesion to a soft metal, the hard coating film being suitable for
use as a coating on the surface of, for example, a die in contact
with the soft metal. Further, the hard coating film includes a
metal element containing at least two species of elements selected
from the group consisting of Ti, Al, and Cr, and a non-metal
element containing O (oxygen) only, or O and at least one species
selected from the group consisting of C and N. A proportion
accounting for the O in the total non-metal element is not less
than 0.2, in atom ratio.
Inventors: |
YAMAMOTO; Kenji; (Kobe-shi,
JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
KABUSHIKI KAISHA KOBE SEIKO SHO (KOBE STEEL, LTD.) |
Kobe-shi |
|
JP |
|
|
Assignee: |
KABUSHIKI KAISHA KOBE SEIKO SHO
(KOBE STEEL, LTD.)
Kobe-shi
JP
|
Family ID: |
51261936 |
Appl. No.: |
15/232601 |
Filed: |
August 9, 2016 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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14760533 |
Jul 13, 2015 |
9410235 |
|
|
PCT/JP2013/084853 |
Dec 26, 2013 |
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15232601 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
C23C 14/325 20130101;
C23C 14/0036 20130101; C23C 14/35 20130101; C23C 14/08 20130101;
B41J 2/11 20130101; C09D 1/00 20130101; B21D 37/01 20130101; C23C
14/0676 20130101; B21D 22/208 20130101; B21D 28/00 20130101; C23C
14/028 20130101; C23C 14/3414 20130101 |
International
Class: |
B21D 37/01 20060101
B21D037/01; C23C 14/06 20060101 C23C014/06; C23C 14/00 20060101
C23C014/00; B21D 28/00 20060101 B21D028/00; C23C 14/35 20060101
C23C014/35; C23C 14/32 20060101 C23C014/32; B21D 22/20 20060101
B21D022/20; C23C 14/02 20060101 C23C014/02; C23C 14/34 20060101
C23C014/34 |
Foreign Application Data
Date |
Code |
Application Number |
Jan 29, 2013 |
JP |
2013-014676 |
Claims
1. A hard coating, comprising: at least two metal elements selected
from the group consisting of Ti, Al, and Cr; and a non-metal
element comprising O (oxygen) only, or comprising O and at least
one element selected from the group consisting of C and N, relative
to the non-metal element in total, an atomic ratio of O is not less
than 0.2.
2. The hard coating film according to claim 1, having a surface
with an arithmetic-mean roughness of 0.01 .mu.m or more and 3 .mu.m
or less.
3. (canceled)
4. The hard coating film according to claim 1, wherein the metal
elements comprises Ti, Cr, and Al, and relative to the metal
elements in total, Ti, Cr, and Al have the following atomic ratios,
respectively: Ti: 0.10 or more and 0.40 or less; Cr: 0.10 or more
and 0.40 or less; and Al: 0.40 or more and 0.70 or less.
5. The hard coating film according to claim 1, wherein the metal
elements comprise Ti, Cr, Al, and Si, and relative to the metal
elements in total, Ti, Cr, Al, and Si have the following atomic
ratios, respectively: Ti: 0.10 or more and 0.40 or less; Cr: 0.10
or more and 0.40 or less; Al: 0.40 or more and 0.70 or less; and
Si: 0.010 or more and 0.10 or less.
6. The hard coating film according to claim 1, wherein a part of
the metal elements is replaced with at least one species of metal
element selected from the group consisting of a group 4 elements, a
group 5 elements, a group 6 element, Si, Y, and B, and relative to
the metal elements in total, an atomic ratio of the part replaced
is up to 0.2.
7. A die, having a surface coated with the hard coating film
according to claim 1.
8. A method for making a hot-working workpiece, the method
comprising: employing the die according to claim 7 in making the
hot-working workpiece, composed of at least one species of soft
metal selected from the group consisting of Zn, Sn, Al, and Mg.
9. A method for making a hot-working Zn-coated steel sheet, the
method comprising: employing the die according to claim 7 in making
the hot-working Zn-coated steel sheet.
10-12. (canceled)
13. A die, having a surface coated with the hard coating film
according to claim 2.
14. (canceled)
15. The hard coating film according to claim 1, which has a
thickness of 0.5 .mu.m to 10 .mu.m.
16. The hard coating film according to claim 1, which has a
thickness of 0.5 .mu.m to 5 .mu.m.
17. The hard coating film according to claim 1, wherein the metal
elements comprise Ti, Cr and Al.
18. The hard coating film according to claim 1, wherein the metal
elements comprise Ti, Cr, Al and Si.
19. The hard coating film according to claim 1, having a surface
with an arithmetic-mean roughness of 0.1 .mu.m or more and 2.5
.mu.m or less.
20. The hard coating film according to claim 1, having a surface
with an arithmetic-mean roughness of 0.5 .mu.m or more and 2 .mu.m
or less.
21. The hard coating film according to claim 1, wherein the
non-metal element comprises O only.
22. The hard coating film according to claim 1, wherein the
non-metal element comprises O and at least one element selected
from the group consisting of C and N.
23. The hard coating film according to claim 1, wherein relative to
the non-metal element in total, the atomic ratio of O is not less
than 0.5.
24. The hard coating film according to claim 1, wherein relative to
the non-metal element in total, the atomic ratio of O is not less
than 0.7.
Description
TECHNICAL FIELD
[0001] The invention relates to a hard coating film having
anti-adhesion property to a soft metal.
BACKGROUND ART
[0002] In the case of processing or sliding against a steel sheet
with the surface thereof being made of a soft metal such as Zn,
etc., that is, for example, a Zn-coated steel sheet, a problem can
occur in that the soft metal adheres to the surface of a member
(for example, a die, etc.) in contact with the soft metal to be
further deposited on the surface of the member, thereby impairing
the surface quality of a workpiece.
[0003] More specifically, there exists, for example, the following
problem with a hot pressing method, as hot forming. The hot
pressing (also called as "die-quench") method represents a
technique whereby, upon a steel sheet (blank) being heated to a
temperature (normally, 800 to 900.degree. C.) in an austenite
region to be quenched in a water-cooled die, the steel sheet is
formed into the desired shape of a part. Process-steps from the
heating of a steel sheet up to press working are carried out in the
atmosphere from the view point of a cost, and therefore, for the
purpose of controlling scale-formation due to oxidation of a steel
sheet, a plated steel sheet with a plating layer composed of,
primarily Al or Zn, formed on the surface thereof, is used for the
steel sheet. However, in the case of using the plated steel sheet,
that is, the zinc (Zn)-coated steel sheet in particular, Zn is
adhered to a die for pressing along with an increase in the number
of shots, thereby reaching a stage in which the die undergoes a
change in shape in extreme cases, whereupon there arises a problem
with a product shape, and the surface quality of a steel sheet as
formed.
[0004] In general, a die for use in the hot pressing, and so forth
is formed after coating the surface of the die with a ceramic film
of TiN, etc., as countermeasures against abrasion wear. Even in
this case, however, anti-adhesion property to the soft metal is far
from sufficient.
SUMMARY OF INVENTION
Technical Problem
[0005] The present invention has been developed by taking note of
the circumstances described as above, and it is therefore an object
of the invention to provide a hard coating film insusceptible to
adhesion to the soft metal, and a die serving as a
hard-coating-film coating-member, in particular.
[0006] There is described below the case where the surface of a
jig-tool (a die, in particular) is coated with the hard coating
film according to the invention to serve as the hard-coating-film
coating-member, by way of example, however, the hard coating film
according to the invention may be formed on the surface of a
slidable member, and so forth, as described later on.
Solution to Problem
[0007] According to the present invention which solves the above
problem, there is provided a hard coating film having anti-adhesion
property to a soft metal, including a metal element containing at
least two species of elements selected from the group consisting of
Ti, Al, and Cr, and a non-metal element made of O (oxygen) only, or
O and at least one species selected from the group consisting of C
and N. A proportion accounting for the O in the total non-metal
element is not less than 0.2, in atom ratio.
[0008] According to another hard coating film of the present
invention having anti-adhesion property to a soft metal may have
arithmetic-mean roughness (Ra) of a surface thereof at 0.01 .mu.m
or more and 3 .mu.m or less.
[0009] As preferable embodiments of the present invention, there is
provided the hard coating film, satisfying the arithmetic-mean
roughness (Ra) of a surface thereof, at 0.01 .mu.m or more and 3
.mu.m or less, and including a metal element containing at least
two species of elements selected from the group consisting of Ti,
Al, and Cr; and a non-metal element composed of O (oxygen) only, or
O and at least one species selected from the group consisting of C
and N, a proportion accounting for the O in the total non-metal
element being not less than 0.2 in atom ratio.
[0010] The hard coating film may include [0011] (a) the metal
element composed of Ti, Cr, and Al, proportions (atomic ratios)
accounting for the respective metal elements in the total metal
element being in a range of Ti: 0.10 or more and 0.40 or less, Cr:
0.10 or more and 0.40 or less, and Al: 0.40 or more and 0.70 or
less, and [0012] (b) the metal element composed of Ti, Cr, Al, and
Si, proportions (atomic ratios) accounting for the respective metal
elements in the total metal element being in a range of Ti: 0.10 or
more and 0.40 or less, Cr: 0.10 or more and 0.40 or less, Al: 0.40
or more and 0.70 or less, and Si: 0.010 or more and 0.10 or
less.
[0013] A part of the metal elements may be replaced with at least
one species of metal element selected from the group consisting of
the group 4 elements, the group 5 elements, and the group 6
elements, according to the periodic table, Si, Y, and B, up to 0.2,
as the upper limit of the proportion (atom ratio) accounting for
the part of the metal elements in the total metal element.
[0014] The resent invention includes a die, the surface thereof
being coated with the hard coating film.
[0015] If the die is used for the hot-working of a workpiece (for
hot working of a Zn-coated steel sheet, in particular), composed of
at least one species of soft metal selected from the group
consisting of Zn, Sn, Al, and Mg, the advantageous effects of the
present invention is sufficiently exhibited.
Advantageous Effects of Invention
[0016] The hard coating film according to the present invention is
excellent in anti-adhesion property to a soft metal (hereinafter
referred to simply as "anti-adhesion property" on occasion).
Accordingly, if the hard coating film according to the present
invention is formed on the surface of a die.cndot.jig (hereinafter
generically called "jig-tool") for use in, for example, plastic
processing, and cutting process, or cutting work, etc., it is
possible to control adhesion of the soft metal, on the surface of
the jig-tool, occurring at a time when the jig-tool comes into
contact with a workpiece made up of the soft metal. Even in the
case where the processing described as above is hot working (hot
pressing which is hot forming, in particular), it is possible to
control the adhesion of the soft metal, on the surface of the
jig-tool. As a result, the jig-tool can be stably and repeatedly
used over the long term.
DESCRIPTION OF EMBODIMENTS
[0017] The inventors have repeatedly continued strenuous studies in
order to solve the problem described as above. As a result, the
inventors have found that in order to enhance anti-adhesion
property of the jig-tool against a soft metal, it is effective to
form a hard coating film on the top surface of the jig-tool, the
hard coating film whose insulating properties are enhanced by
causing O (oxygen) to be contained therein.
[0018] In order to cause the hard coating film to exhibit excellent
anti-adhesion property, a proportion accounting for the O in the
total non-metal element making up the hard coating film need be not
less than 0.2, in atom ratio. The proportion (atom ratio) of the O
is preferably not less than 0.5, and more preferably not less than
0.7. There is no particular upper limit to the proportion of the 0,
and the non-metal elements may be oxygen only (in other words, the
proportion accounting for the O in the total non-metal element may
be 1 in terms of the atom ratio).
[0019] The non-metal element is composed of the O (oxygen) only, or
O and at least one species selected from the group consisting of C
and N. If the O, together with the at least one species selected
from the group consisting of C and N is contained as the non-metal
element, the hardness of the hard coating film can be further
increased. The proportion (atom ratio, or the total atom ratio if
both C and N are contained) accounting for the at least one species
in the total non-metal element can be not less than 0.10 (further,
not less than 0.20). Furthermore, the upper limit of the atom ratio
of the at least one species selected from the group consisting of C
and N will be at 0.8 on the basis of the proportion of the O.
[0020] The hard coating film according to the present invention
contains at least two species of elements selected from the group
consisting of Ti, and Cr, as metal elements. Further, a part of the
metal elements may be replaced with at least one species of metal
element (hereinafter, referred to as "X-group element" on occasion)
selected from the group consisting of the group 4 elements, the
group 5 elements, and the group 6 elements, according to the
periodic table, Si, Y, and B, up to 0.2, as the upper limit of the
proportion (atom ratio indicating a single quantity in the case of
a single element, while indicating the total quantity in the case
of plural elements) accounting for the part of the metal elements
in the total metal element. If the X-group element is contained, an
X-group element quantity can be, for example, not less than 0.01.
The anti-adhesion property will not deteriorate due to displacement
described as above.
[0021] With the hard coating film according to the present
invention, a contact (slidable) target thereof is mainly a soft
metal, such as Zn, and Sn, etc., however, in the case where the
contact (slidable) target is the Zn-coated steel sheet, a portion
of the steel sheet, without zinc-plating being formed, (that is,
the steel sheet) can occasionally end up in serving as the slidable
target. Furthermore, in the case of hot working, there occurs
contact with the steel sheet heated to a high temperature.
Accordingly, heat resistance/oxidation resistance, as well, are
required of the hard coating film. From the viewpoint of imparting
these properties (the oxidation resistance, in particular) to the
hard coating film, the metal elements of the hard coating film
preferably contain TiAl, CrAl, TiCrAl, or these metal elements with
Si additionally contained therein, more preferably the metal
elements containing TiCrAl or TiCrAlSi.
[0022] In the case of the metal elements containing TiCrAl, the
proportions (the atomic ratios) accounting for the respective metal
elements in the total metal element are preferably in a range of
Ti: 0.10 or more and 0.40 or less, Cr: 0.10 or more and 0.40 or
less, and Al: 0.40 or more and 0.70 or less. Further, in the case
of the metal element being TiCrAlSi, the proportions (the atomic
ratios) accounting for the respective metal elements in the total
metal element are preferably in a range of Ti: 0.10 or more and
0.40 or less, Cr: 0.10 or more and 0.40 or less, Al: 0.40 or more
and 0.70 or less, and Si: 0.010 or more and 0.10 or less.
[0023] Further, the inventors have found that formation of the hard
coating film having a surface whose arithmetic mean roughness (Ra)
satisfies a range of from 0.01 .mu.m up to 3 m, on the top surface
of the jig-tool in contact with the soft metal, is also effective
in enhancement of the anti-adhesion property of the jig-tool
against the soft metal.
[0024] To go into details, the inventors have found that, if, upon
the soft metal coming into contact with the top surface of the
jig-tool, a contact area therebetween is large, adhesion is
susceptible to occur, whereas if the hard coating film opposed to
the top surface of the jig-tool has a suitable roughness in a range
described as above, adhesion is insusceptible to occur. If the Ra
is less than 0.01 .mu.m, the soft metal comes into contact with the
hard coating film across the surface thereof, thereby causing the
contact area to be increased, so that the adhesion is susceptible
to occur. Accordingly, the Ra is set to 0.01 .mu.m or more. The Ra
is more preferably 0.10 .mu.m or more, still more preferably 0.5
.mu.m or more, yet more preferably 1.0 .mu.m or more, and most
preferably 1.5 .mu.m or more. On the other hand, if the Ra exceeds
3 .mu.m, projections on the surface of the hard coating film, that
is, projections on the surface of the jig-tool will be too high,
whereupon a rough surface texture of the jig-tool is printed in the
soft metal as the contact target to thereby increase the surface
roughness of the soft metal. For this reason, this is not
recommendable. Accordingly the Ra is set to 3 .mu.m or less. The Ra
is preferably 2.5 .mu.m or less, and more preferably 2 .mu.m or
less.
[0025] The Ra is measured by a method described in a working
example described later on in the present description.
[0026] For a method of forming the hard coating film according to
the present invention, vapor phase coating methods, such as an ion
plating method (for example, the AIP method: Arc Ion Plating
method, etc.), a sputtering method can be used. In order to obtain
the hard coating film having the Ra described as above, it is
recommendable to adjust the surface roughness of a substrate before
formation of the hard coating film to subsequently form the hard
coating film as smooth as possible on the surface of the substrate,
as described later on, thereby reproducing a surface-texture of the
substrate so as to be faithful to a surface texture of the hard
coating film. In order to form the hard coating film as smooth as
possible, a filtered arc ion plating method, or the sputtering
method is preferably used among the vapor phase coating methods.
With the use of the sputtering method, in particular (further, a
UBMS (Unbalanced Magnetron Sputtering) method, in particular), the
hard coating film more excellent in anti-adhesion property can be
formed because a particle acting as the starting point of a
pin-hole does not occur in theory. For a deposition condition in
forming the film by use of the respective methods described as
above, it need only be sufficient to adopt a general condition. In
forming the hard coating film according to the present invention by
use of any of those methods, the target made of the metal element
(including the X-group element, as necessary) of the hard coating
film is used, while using an atmospheric gas including an oxygen
gas, a nitrogen gas as necessary a hydrocarbon gas, such as
methane, etc., and Ar gas, etc.
[0027] Further, in the case of the filtered arc ion plating method,
the deposition condition includes, for example, a substrate
temperature: 300 to 700.degree. C., a bias voltage: -30 to -70V (by
minus notation of a bias voltage is meant a substrate at a minus
potential against the earth potential and the same applies
hereinafter), and a total gas-pressure: 1 to 5 Pa. In the case of
the sputtering method, a deposition condition includes, for
example, a substrate temperature: 300 to 700.degree. C., an input
electric-power: for example, 3 kW (in the case of a target diameter
being at 6 inches), and the total gas-pressure: for example, 0.6
Pa.
[0028] In order to obtain the hard coating film having the (Ra), it
is recommendable to adjust the surface roughness of the substrate
before the formation of the hard coating film, as described in the
foregoing. The roughness of a substrate surface before coating with
the hard coating film is not necessarily required to fall within
the range of the Ra of the hard coating film. There is cited a
method whereby the substrate surface is worked on by use of, for
example, shot blasting, and so forth, to thereby cause the Ra of
the substrate surface to fall within a range of, for example, Ra
1.5 .mu.m.+-.20%, subsequently forming the hard coating film on the
substrate surface. In order to remove a sharp angle having occurred
by application of the shot blasting, it is recommendable to further
apply polishing by use of, for example, projection polishing,
within a range where the shape of the substrate surface is not
caused to undergo a large change. Further, in order to remove the
particle, and so forth, attached to the surface of the hard coating
film, it is recommendable to apply for example, the projection
polishing after the formation of the hard coating film.
[0029] The present invention includes a die, in particular, as
well, serving as a hard-coating-film coating-member with the hard
coating film being coated on the surface (the top surface)
thereof.
[0030] If the hard-coating-film coating-member (the die, in
particular, and a hot-press die, in more particular) is used in the
case of applying the hot working (hot pressing using the Zn-coated
steel sheet susceptible to adhesion, for use as a workpiece, in
particular) to a workpiece (a workpiece for forming), at least the
surface thereof being composed of a soft metal (Zn, etc.), this
will enable the advantageous effects of the present invention to be
sufficiently exhibited.
[0031] A metal and an alloy, made of at least one species of
element selected from the group consisting of Zn, Sn, Al, and Mg,
is cited as the soft metal.
[0032] The "workpiece (workpiece for forming), at least the surface
thereof being made of the soft metal (Zn, etc.)" includes a
pure-aluminum material, an aluminum-based alloy-material, a pure-Sn
material, an Sn-based alloy-material, a pure-Zn material, a
Zn-based alloy-material, and an Mg-based alloy-material, etc.,
besides a metal sheet (for example, a steel sheet) provided with a
plating layer of the at least one species of element selected from
the group consisting of Zn, Sn, Al, and Mg. If the Zn-coated steel
sheet (including a hot-dip galvanizing-coated steel sheet (GI), a
hot-dip galvannealing-coated steel sheet (GA), and an
electrogalvanizing steel sheet (EG)), in particular, is used as the
workpiece (the workpiece for forming) described as above, the
advantageous effects of the present invention are sufficiently
exhibited.
[0033] A method for processing a workpiece, other than the plated
steel sheet, includes, for example, forging of an Al-based metal,
Al die-casting, Zn die-casting, Mg die-casting, and so forth.
[0034] The hard coating film according to the present invention can
be applied to a die used in forging, and extrusion, etc., the
jig-tool (including a cutting tool, such as a tip, a drill, an end
mill, etc., and a blanking punch, etc.), and a slidable member of
automobile part as well as machine parts, etc., serving as the
hard-coating-film coating-member, respectively, besides the
hot-press die described as above.
[0035] If at least a portion of the hard-coating-film
coating-member (the die, in particular), in contact with the soft
metal, is coated with the hard coating film according to the
present invention, this will be sufficient whatever coating on a
portion of the hard coating film, out of contact with the soft
metal, may be.
[0036] A film thickness of the hard coating film according to the
present invention is preferably not less than 0.5 .mu.m. This is
because coating will be insufficient if the film thickness is less
than 0.5 .mu.m, so that the substrate will be exposed on occasion.
The film thickness is more preferably not less than 1 .mu.m. On the
other hand, if the film thickness of the hard coating film is
excessively large, peel off is susceptible to occur, so that the
film thickness of the hard coating film is preferably not more than
10 .mu.m. The film thickness is more preferably not more than 5
.mu.m.
[0037] It need only be sufficient to have the hard-coating-film
coating-member (the die, in particular), the top surface thereof
being made up of the hard coating film specified by the present
invention, and a hard coating film other than the hard coating film
specified by the present invention, and an intermediate layer, such
as CrN, and TiN, etc., may be formed between the hard coating film
on the top surface and the substrate.
[0038] This application claims a Convention Priority on Japanese
Patent Application No. 2013-014676, submitted for application on
Jan. 29, 2013, which is incorporated herein by reference. The whole
contents of Japanese Patent Application No. 2013-014676, submitted
for application on Jan. 29, 2013, are incorporated herein by
reference.
WORKING EXAMPLES
[0039] Referring to working examples, the present invention is more
specifically described hereunder, however, it is to be understood
that the present invention is obviously not limited thereto. It
should be understood that the present invention can be practiced by
addition of various modifications as appropriate in the light of
teachings described in the foregoing and later on, and any of the
modifications is to be included in the technical scope of the
present invention.
Working Example 1
[0040] In the case of Working Example 1, a (TiCrAlSi) film, and an
(ON) film (the compositions of the respective films, in atom ratio,
are (Ti: 0.20, Cr: 0.20, Al: 0.55, and Si: 0.05) and (O: 0.80, N:
0.20)) were used, and surface roughness was varied, thereby having
reviewed the effect of the surface roughness, exerted on
anti-adhesion property.
[0041] There was prepared an SKD61 die (substrate), which is a
steel material of an alloy tool steel according to JIS standard,
for use in evaluation of surface roughness, and evaluation of
anti-adhesion property.
[0042] Mirror polishing or the shot blasting was applied to the
substrate, as shown in Table 1, prior to formation of a coating,
having thereby adjusted roughness of the substrate to a value close
to the Ra shown in Table 1. Subsequently, the coating about 3 .mu.m
was formed by use of the filtered arc ion plating method (denoted
as "filtered AIP" in Table 1), or the unbalanced magnetron
sputtering method (denoted as "UBMS" in Table 1).
[0043] In the case of the filtered arc ion plating method (the
filtered AIP), a deposition condition included a substrate
temperature: 400.degree. C., a total gas-pressure: 2 Pa, and a bias
voltage: -70V. Further, in the case of the unbalanced magnetron
sputtering method (the UBMS), a deposition condition included a
substrate temperature: 400.degree. C., a total gas-pressure: 0.6
Pa, and an input electric-power: 3 kW (in the case of a target
diameter being at 6 inches). With either of those methods, a
TiCrAlSi target, the composition (in atom ratio) thereof being (Ti:
0.20, Cr: 0.20, Al: 0.55, and Si: 0.05) was used, as the target.
Further, for an atmospheric gas at the time of forming the film, a
mixed gas of oxygen+nitrogen was used in the case of the filtered
AIP, while a mixed gas of argon+oxygen+nitrogen was used in the
case of the UBMS. Furthermore, samples (Sample No. 1, and Sample
No. 2), without the coating formed therein, were also prepared as
Comparative Samples.
[0044] Then, the polishing of a coating surface was executed by use
of a projection-type polishing machine (Aero lap (registered
trademark) manufactured by Yamashita Works Co., Ltd.) after the
formation of the film, thereby having produced samples whose Ra
values shown in Table 1 were found various. In the present working
example, execution time of the shot blasting as a method for
adjusting a substrate surface, and the size of a projection
particle used in the shot blasting, as shown in Table 1, were
varied, thereby having produced samples whose Ra values differ from
each other although the component composition of the coating as
well as the method for forming the film were not varied.
TABLE-US-00001 TABLE 1 Pretreatment of Film-forming Adhesion No.
substrate-surface Coating* method Post treatment Ra (.mu.m) amount
1 Mirror polishing None None -- 0.005 5 2 Shot blasting (#80) None
None -- 1.5 4 3 Mirror polishing TiCrAlSi(ON) Filtered AIP Yes 0.01
3 4 Shot blasting (#200) TiCrAlSi(ON) Filtered AIP Yes 0.076 3 5
Shot blasting (#200) TiCrAlSi(ON) Filtered AIP Yes 0.132 2 6 Shot
blasting (#100) TiCrAlSi(ON) Filtered AIP Yes 0.18 2 7 Shot
blasting (#80) TiCrAlSi(ON) Filtered AIP Yes 0.7 1 8 Shot blasting
(#80) TiCrAlSi(ON) Filtered AIP Yes 1.5 0 9 Shot blasting (#30)
TiCrAlSi(ON) UBMS Yes 1.7 0 10 Shot blasting (#30) TiCrAlSi(ON)
Filtered AIP Yes 2.5 0 11 Shot blasting (#30) TiCrAlSi(ON) Filtered
AIP Yes 3 2 12 Shot blasting (#30) TiCrAlSi(ON) Filtered AIP Yes 4
4 *TiCrAlSi(ON) = (Ti0.20Cr0.20Al0.55Si0.05)(O0.80N0.20) (A
numerical value indicates an atom ratio.)
[0045] Using these samples, evaluation of the surface texture of a
coating (Ra), and evaluation of anti-adhesion property were
executed as follows.
[0046] Measurement of Surface Roughness (Ra)
[0047] The Ra of each of the samples was measured by a method
provided in JIS B0601, shown in Table 2 (a cutoff value and an
evaluation length, at the time of finding Ra, are shown) with the
use of a contact-finger type surface-roughness tester.
TABLE-US-00002 TABLE 2 Evaluation Ra range Cutoff value length
(.mu.m) .lamda..sub.c l.sub.n in excess of or less (mm) (mm)
(0.006) 0.02 0.08 0.4 0.02 0.1 0.25 1.25 0.1 2.0 0.8 4 2.0 10.0 2.5
12.5 10.0 80.0 8 40 Shown inside ( ) is a reference value.
[0048] A measurement described as above was conducted at five
optional spots on the surface of the coating, thereby having
adopted an average value of respective values obtained by the
measurements. Further, the sample No. 1, and the sample No. 2 each
being the example in which the coating was not formed, Ra in Table
1 indicates the results of each measurement on the surface
roughness of the substrate simply for the purposes of
reference.
(Evaluation of Anti-Adhesion Property to Soft Metal)
[0049] Zn was selected as a representative of the soft metal, while
the hot-dip galvannealing-coated steel sheet (GA) (Zn-coated steel
sheet) was prepared as a sheet material (blank). Then, bending, by
use of a bending die with--without the coating, was applied to the
Zn-coated steel sheet heated to the following temperature under the
following deposition condition, having thereby looked into a
Zn-adhesion state on the surface of the bending die after
processing
(Deposition Condition)
[0050] sheet material (blank): a hot-dip galvannealing-coated (GA)
steel sheet (tensile strength: 590 MPa, sheet thickness: 1.4 mm),
bending die material: SKD61 which is the steel material of the
alloy tool steel according to JIS standard+the respective coatings
shown in Table 1, thrust load: 1 t heating temperature: 760.degree.
C.
[0051] Subsequently, the Zn-adhesion state was classified into six
stages as shown in the following evaluation criterions, thereby
having evaluated Zn-adhesion state such that the stage 3 or lower
was excellent in anti-adhesion property.
(Evaluation Criterions)
[0052] A proportion (%) of a Zn-adhesion area on the surface of the
bending die, in contact with the sheet material, was found, thereby
having made evaluations in 0 through 5 stages as follows:
[0053] 5: in excess of 60%
[0054] 4: in excess of 30%, 60% or less
[0055] 3: in excess of 20%, 30% or less
[0056] 2: in excess of 10%, to 20% or less
[0057] 1: in excess of 5%, to 10% or less
[0058] 0: 5% or less
[0059] These results are shown in Table 1.
[0060] The following is evident from Table 1. Because Sample No. 1
has no coating on the surface of the die, and the surface was
smooth, an adhesion amount of the soft metal was considerably
increased. Further, Sample No. 2 has no coating on the surface of
the die either, however, because the surface roughness of the die
is controlled by virtue of the shot blasting in this case, an
adhesion amount of the soft metal was found less than that in the
case of the die whose surface was subjected to the mirror
polishing.
[0061] Sample No. 12 has a coating formed on the surface of the
die, but Ra on the surface of the coating is excessively large in
value, and therefore, an adhesion amount of the soft metal was
increased.
[0062] In each of Samples Nos. 3 through 11, a hard coating film,
Ra thereof being within a prescribed range of the present
invention, was formed to serve as a coating, and it is evident that
an adhesion amount of a soft metal can be sufficiently controlled
by use of a die with the hard coating film formed on the surface
thereof.
[0063] Furthermore, Ra on the surface of a coating, in the
respective cases of Sample No. 3 and Sample No. 4, was smaller in
value than that in the respective cases of Samples Nos. 5 through
11, while an adhesion amount of a soft metal in the former cases
was found greater in value than that in the latter cases although
an adhesion amount of a soft metal was within tolerance.
Working Example 2
[0064] In Working Example 2, there were formed various coatings
having surface roughness that is substantially fixed, and the
component compositions differing from each other, thereby having
reviewed the effect of the component composition of a film, exerted
on the anti-adhesion property.
[0065] To describe in detail, shot blasting with the use of a
bending die as a substrate was applied prior to formation of a
coating on the surface of the substrate, and subsequently, coatings
of various component-compositions shown in Table 3 were formed by
use of a film-forming method shown in Table 3, and the polishing of
a coating surface was carried out in the same way as in the case of
Working Example 1, thereby rendering surface roughness with respect
to any of samples to be substantially fixed (Ra: 1.5 to 1.7
.mu.m).
[0066] For the formation of the coatings described as above,
respective targets made of metal elements contained in the
respective coatings shown in Table 3 were used. Further, in the
case of Sample Nos. 1 through 4, an atmospheric gas at the time of
forming the film was a pure nitrogen gas, while, in the cases of
Sample Nos. 5 through 9, Sample Nos. 11 through 13, and Sample Nos.
15 through 19, respectively, the atmospheric gas at the time of
forming the film was a mixed gas of oxygen+(at least one species
selected from the group consisting of nitrogen and methane). In the
cases of Sample No. 10, and No. 14, respectively, the atmospheric
gas at the time of forming the film was a pure oxygen-gas. Other
aspects of a sample-preparation condition, including the deposition
condition, were the same as in the case of Working Example 1.
[0067] The evaluation of anti-adhesion property, using the samples
obtained, was conducted in the same way as in the case of Working
Example 1. The results of the evaluation are shown in Table 3.
TABLE-US-00003 TABLE 3 Film-forming Adhesion No. Coating* method
amount 1 TiN Filtered AIP 3 2 CrN Filtered AIP 3 3 (Ti0.50Al0.50)N
Filtered AIP 3 4 (Ti0.20Cr0.20Al0.55Si0.05)N Filtered AIP 3 5
(Ti0.20Cr0.20Al0.55Si0.05)(O0.10N0.90) Filtered AIP 3 6
(Ti0.20Cr0.20Al0.55Si0.05)(O0.20N0.80) Filtered AIP 2 7
(Ti0.20Cr0.20Al0.55Si0.05)(O0.35N0.65) Filtered AIP 1 8
(Ti0.20Cr0.20Al0.55Si0.05)(O0.50N0.50) Filtered AIP 1 9
(Ti0.20Cr0.20Al0.55Si0.05)(O0.70N0.30) Filtered AIP 0 10
(Ti0.20Cr0.20Al0.55Si0.05)O Filtered AIP 0 11
(Ti0.40Al0.60)(O0.90N0.10) Filtered AIP 2 12
(Al0.50Cr0.40Si0.10)(O0.85N0.15) Filtered AIP 1 13
(Ti0.25Cr0.10Al0.65)(O0.90N0.10) Filtered AIP 1 14 (Ti0.50Cr0.50)O
Filtered AIP 3 15 (Ti0.20Cr0.20Al0.55Si0.03Y0.02)(O0.80N0.20)
Filtered AIP 0 16 (Al0.50Cr0.40W0.10)(O0.90N0.10) Filtered AIP 2 17
(Ti0.20Cr0.20Al0.55Si0.05)(O0.50N0.30C0.20) Filtered AIP 1 18
(Ti0.20Cr0.20Al0.55Si0.05)(O0.50N0.10C0.40) Filtered AIP 1 19
(Ti0.20Cr0.20Al0.55Si0.05)(O0.50C0.50) Filtered AIP 1 *A numerical
value indicates an atom ratio. Further, each Ra value on the
surface of the coating was within a range of 1.5 to 1.7 .mu.m.
[0068] The following is evident from Table 3. Sample Nos. 1 through
5 each are a sample in which the surface roughness as prescribed is
satisfied. Because these samples either contain no oxygen (O), or
is short in oxygen, an adhesion amount of a soft metal was on a
slightly higher side.
[0069] In the case of each of Sample Nos. 6 through 19, the hard
coating film according to the present invention, satisfying both
the surface roughness as prescribed and the component composition
as prescribed, was formed so as to serve as the coating, so that if
a die with the hard coating film formed on the surface thereof is
used, it is evident that the adhesion amount of the soft metal can
be sufficiently controlled. In the case of Sample Nos. 5 through 9,
metal elements making up the hard coating film, in the respective
samples, are identical to each other, while a ratio of non-metal
element O to N is varied and it is evident that as a proportion
accounting for an oxygen quantity in the non-metal element in the
hard coating film becomes greater, so the adhesion amount of the
soft metal tends to be smaller.
* * * * *