The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Sep. 07, 1993
Filed:
Feb. 26, 1991
Katsuhisa Maruyama, Tsukuba, JP;
Mitsuo Makino, Tsukuba, JP;
Nobuyuki Kikukawa, Tsukuba, JP;
Minoru Shiraishi, Kawasaki, JP;
Agency of Industrial Science and Technology, Tokyo, JP;
Abstract
An improved method is proposed for providing a coating film of diamond on the surface of, for example, a cutting tool as the substrate by the plasma jet deposition method, in which the deposited diamond film has, different from the cubic crystalline structure formed under conventional conditions, a predominantly hexagonal crystalline structure so as to greatly enhance the advantages obtained by the diamond coating of the tool in respect of the hardness and smoothness of the coated surface. The improvement comprises: using hydrogen alone as the plasma-generating gas; controlling the pressure of the plasma atmosphere not to exceed 300 Torr; keeping the substrate surface at a temperature of 800.degree.-1200.degree. C.; and making a temperature gradient of at least 13,000.degree. C./cm within the boundary layer on the substrate surface.