Abstract Herein disclosed is an improved wear-resistant metal object and a method for the manufacture thereof. The metal object is formed by spraying fine particles of a nickel-chrome based self-fluxing alloy onto a surface of a base metal for forming a coating of the alloy on at least a portion of the surface of the base metal. The coating is usually fused so as to have the particles of the selffluxing alloy interlocked with each other and strongly bonded to the base metal. Where desired, the resultant object is subjected to a soft-nitriding process for forming a nitrided hardened layer on the resultant object. The metal object thus produced has an increased resistance to wear and abrasion and is adapted for use in operations in which sliding movements occur in severe conditions as in the case of an apex seal of a Wankel rotary engine.
A wear-resistant apex seal of a Wankel type rotary engine as claimed in claim 1, in which said coating is about 0.3 to 1.0 mm thick.
Claim 2
Dependent Claim
36 words
A wear-resistant apex seal of a Wankel type rotary engine as claimed in claim 1, wherein the nitrided layer is formed on the entire surfaces of said coating and any uncoated area of said base metal.
Claim 3
Independent Claim
147 words
A method for producing a wear-resistant apex seal of a Wankel type rotary engine, comprising the steps of spraying an atomized self-fluxing alloy comprising a base alloy selected from the group consisting of nickel based alloy, nickel-chrome based alloy, and cobalt-chrome-molybdenum-iron based alloy and at least one self-fluxing component selected from the group consisting of boron and silicon on at least a portion of a base metal selected from a group consisting of soft steel, structural steel, cast iron, cast steel, copper, a copper alloy and Monel metal for forming a coating thereon, fusing said coating at a temperature ranging from about 1,050*C to about 1,250*C, and subsequently heating said coating at a temperature of about 570*C. in the presence of a bath of molten potassium cyanate for a period of time from about 60 to about 120 minutes for forming an outer layer of metal nitride.
Claim 4
Dependent Claim
18 words
A method as claimed in claim 4, in which said coating is about 0.3 to 1.0 mm thick.
Claim 5
Dependent Claim
17 words
A method as claimed in claim 4, in which said self-fluxing alloy is nickel and chrome based.
Claim 6
Dependent Claim
15 words
A method as claimed in claim 4, in which said self-fluxing alloy is cobalt-chrome-molybdenum-iron based.