Production of surface-coated tungsten carbide-base sintered hard alloy

Abstract

Abstract PURPOSE:To strengthen the adhesion of a hard coating layer to a substrate surface by etching the substrate surface with an acid to remove the binding layer forming component on the surface prior to the formation of the hard coating layer on the surface of a substrate of a WC-base sintered hard alloy under specified conditions. CONSTITUTION:WC is used as the essential component, and >=1 kind among iron-group metals are incorporated as a binding phase forming component to form a WC-base sintered hard alloy. The WC-base sintered hard alloy is used as the substrate, and a hard coating layer consisting of the single layer of one kind among the carbides of groups 4a, 5a, and 6a metals of the periodic table, the nitrides of groups 4a and 5a metals, the oxides of group 4a metals, the solid soln. of >=2 kinds of the metals, and Al2O3 or the plural layers of >=2 kinds is formed on the surface by chemical vapor deposition. At this time, the substrate surface is etched by an acid (nitric acid soln.) to remove the binding phase forming component on the substrate surface part prior to the formation of the hard coating layer. Consequently, the peeling of the hard coating layer off the substrate is prevented.

Inventors

• 👤 Hironori Yoshimura
• 👤 吉村　寛範
• 👤 Giichi Okada
• 👤 義一 岡田
• 👤 Akira Osada
• 👤 晃 長田

Bibliographic Details