Abrasion resistant coated articles

Details Abrasion resistant coated articles Abrasion resistant coated articles

1994-01-18

2001-05-08

Turner, Archene (Department: 1775)

Stock material or miscellaneous articles

Web or sheet containing structurally defined element or...

Physical dimension specified

C057S307000, C057S309000, 62, 62, 62, 62, C428S701000

Reexamination Certificate

active

06228483

ABSTRACT:

BACKGROUND OF THE INVENTION
The invention relates to abrasion resistant coated articles, for example, cutting tools.
Metal cutting and other wear applications require cutting tools and abrasive materials with particular surface and bulk properties. The tool surface must be chemically inert and resistant to mechanical wear, while the bulk material must be tough and resistant to plastic deformation, as well as to crack generation and propagation. These requirements have been satisfied by substrate and applied coating optimization.
Titanium and its alloys present particular challenges for cutting tool design. Titanium is characterized by a low thermal conductivity, a low specific heat, and a high melting point. These properties result in high cutting temperatures even at moderate cutting speeds. Furthermore, titanium displays high chemical reactivity at these high cutting temperatures. To date, no coated cutting tool has been found to be satisfactory for titanium machining. Currently, the best available tool material for titanium machining is cemented tungsten carbide cobalt (WC—Co), which maintains shape integrity only at extremely low cutting speeds. Cutting tools are needed capable of machining titanium and other hard to machine materials at high speeds and feed rates. The invention described herein was developed to address this need.
SUMMARY OF THE INVENTION
In one aspect, the present invention provides for coated articles for tribological applications including substrates to which hard phase/binder composite coatings have been applied to provide a wear surface. The substrate includes a cemented carbide, cemented nitride, cemented carbonitride, ceramic, or combinations thereof. A coating about 1-50 &mgr;m, preferably about 1-25 &mgr;m, most preferably about 5-15 &mgr;m thick is deposited on the substrate and provides the wear surface. The coating includes a pore-free, dense, hard phase/cobalt binder composite, the hard phase including tungsten carbide, nitride, or carbonitride. The wear surface includes no cubic carbides to a depth at least sufficient to avoid exposure of cubic carbides to a work-piece during use of the article in tribological applications, so that the coated article provides wear-resistance and chemical inertness and possesses good shape retention at high machining speeds.
The hard phase/cobalt composite of the coatings described herein is a material consisting of particles of tungsten carbide, nitride, or carbonitride interconnected in a cobalt binder. The term “cobalt binder” designates a cobalt or cobalt-based alloy by which hard phase particles are cemented together. As used herein, the term “hard phase particles” can refer to any of a variety of shapes, e.g., a particulate, rod, disk, or whisker morphology, or a combination of such shapes. Typical cemented substrates include cemented refractory metal carbides, nitrides, or carbonitrides. Typical ceramic substrates include ceramics based on, e.g., refractory metal carbides, nitrides, or carbonitrides, alumina, silicon nitride, silicon carbide, or zirconia. The cemented carbide, nitride, or carbonitride, or ceramic substrates can include cubic carbide compounds, i.e., carbides having a cubic crystal structure in an amount up to 50 volume percent. Such carbides include carbides of titanium, zirconium, hafnium, vanadium, niobium, tantalum, and molybdenum. Other metal compounds having a cubic crystalline microstructure are similarly reactive, and present a problem when they contact such titanium containing work-pieces at high machining speeds. Such other cubic compounds include, e.g., cubic nitrides and carbonitrides of titanium, tantalum, hafnium, etc. Thus as used herein, the term “cubic carbides” is intended to refer to such other compounds having a cubic crystalline microstructure as well as to the described carbides themselves.
In a narrower aspect, the coated article is a tungsten carbide/cobalt/cubic carbide (WC—Co-&ggr;) substrate coated with tungsten carbide/cobalt (WC—Co). In another narrower aspect, the coated article is a monolithic or composite ceramic material with a sintering aid in an amount between 0 percent and an amount sufficient to densify the ceramic material to a preselected density. The ceramic material may be, for example, a hard refractory carbide, nitride, or carbonitride of titanium, zirconium, hafnium, vanadium, niobium, tantalum, chromium, or molybdenum, or may be based on silicon nitride, silicon carbide, alumina or zirconia.


REFERENCES:
patent: 3909895 (1975-10-01), Abrahamsol et al.
patent: 4150195 (1979-04-01), Tobioka et al.
patent: 4252862 (1981-02-01), Nishida
patent: 4359335 (1982-11-01), Garner
patent: 4406667 (1983-09-01), Sarin et al.
patent: 4406668 (1983-09-01), Sarin et al.
patent: 4406669 (1983-09-01), Sarin et al.
patent: 4406670 (1983-09-01), Sarin et al.
patent: 4409003 (1983-10-01), Sarin et al.
patent: 4409004 (1983-10-01), Sarin et al.
patent: 4416670 (1983-11-01), Sarin et al.
patent: 4421525 (1983-12-01), Sarin et al.
patent: 4424066 (1984-01-01), Sarin et al.
patent: 4426209 (1984-01-01), Sarin et al.
patent: 4431431 (1984-02-01), Sarin et al.
patent: 4435480 (1984-03-01), Mizuhara
patent: 4440547 (1984-04-01), Sarin et al.
patent: 4441894 (1984-04-01), Sarin et al.
patent: 4449989 (1984-05-01), Sarin et al.
patent: 4469489 (1984-09-01), Sarin et al.
patent: 4497874 (1985-02-01), Hale
patent: 4507151 (1985-03-01), Simm et al.
patent: 4526618 (1985-07-01), Keshavan et al.
patent: 4556607 (1985-12-01), Sastri
patent: 4588606 (1986-05-01), Keshavan et al.
patent: 4698266 (1987-10-01), Buljan et al.
patent: 4701384 (1987-10-01), Sarin et al.
patent: 4702970 (1987-10-01), Sarin et al.
patent: 4705124 (1987-11-01), Abrahamson et al.
patent: 4710425 (1987-12-01), Baldoni, II et al.
patent: 4745010 (1988-05-01), Sarin et al.
patent: 4749629 (1988-06-01), Sarin et al.
patent: 4844951 (1989-07-01), Sarin et al.
patent: 0138228 (1985-04-01), None
patent: 0263747 (1988-04-01), None
patent: 0328084 (1989-08-01), None
patent: 2179678 (1987-03-01), None
patent: 48-32734 (1973-05-01), None
patent: 51-66289 (1976-06-01), None
patent: 56-152541 (1981-11-01), None
patent: 58-209554 (1983-12-01), None
“Production and Properties of Wear-Resistant Coatings With the Aid of Plastic-Bonded Hard Metal/Solder Shapes”, Krappitz et al., Conference: Welding and Cutting 1988,Deutscher Verband fur Schweisstechnik, pp. 45-49 (1988). (no month).
“A Unique Alternative to Carbide, Tool Steel and Flame Sprayed Wear Surfaces”, Reeder,Powder Metallurgy International, 19, p. 39 (1987). (no month).
“New Materials in Plant Construction for the Gas and Petroleum Industries” Belousov,Chemical and Petroleum Engineering, 10, p. 230 (1974). (no month).
“Characterisation and Wear Performance of Plasma Sprayed WC-Co Coatings” Ramnath et al.,Materials Science and Technology, 5, p. 382 (1989). (no month).
“A Technical Assessment of High Velocity Oxygen-Fuel Versus High Energy Plasma Tungsten Carbide-Cobalt Coatings for Wear Resistance” Dorfman et al., Conference: Thermal Spraying,The Welding Institute, 2, p. 291 (1989). (no month).
“High Stress Abrasion of Carbidic Hardfacing Alloys”, Leech,Surface Engineering, 5, p. 41 (1989). (no month).
“Cemented Carbide Cutting Tools”, Sarin, Advances in Powder Technology,Materials Science Seminar, Louisville, Kentucky, ed. Gilbert Y. Chin, p. 253 (1981). (no month).
“Tribological Properties of Ion Plated Coatings”, Berger et al., IPAT 89—Ion and Plasma Assisted Techniques—7th International Conference, p. 262 (1989). (no month).
“Application and Manufacture of CVD Hard-Facing Layers for Cutting and Non-Cutting Shaping”, Schintlmeister et al.,Metall., 34, pp. 905-909 (1980). (no month).
“Peculiarities of Wear Behaviour of Coated Cemented Carbides”, Berger et al., Fifth Polish Conf. on Powder Metallurgy (Proc. Conf.) Poznan, Poland, (III) pp. 71-90, (1979). (no month).
“The Results of Roughness and Wear Tests on Wear-Resistant Coatings” Habig et al.,Hart.-Tech. Mitt., 40, pp. 283-295 (1985). (no month).
Barbezat et al “Applying Tungsten Carbide Cobalt Coatings by Hig

Affiliated with

Also associated with

Rating

Abrasion resistant coated articles does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Abrasion resistant coated articles, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Abrasion resistant coated articles will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-2467756