Patent ID: 6316122
Filing Date: 2001-11-13
Classification: B21C,D01F,Y10S,Y10T

Abstract:
A metal fiber comprising titanium or titanium alloy and having an equivalent area diameter d of 5-30 .mu.m and a specific surface area A (m.sup.2 /g) satisfying A.gtoreq.25/d, wherein said metal fiber comprising titanium or titanium alloy has many fine irregularities on its surface, said metal fiber produced by a bundle-drawing method comprising the steps of:covering a bundle of covered filaments, each of said covered filaments consisting of a core wire made of titanium or titanium alloy and a covering layer formed around the core wire, with an outer housing to form a composite wire;subjecting the composite wire to repetition of cold drawing and heat treatment to form a composite filament; andremoving the portions of the composite filament corresponding to the covering layer and the outer housing to obtain a bundle of metal fibers made of titanium or titanium alloy;wherein the material of each of the covering layer and the outer housing is a mild steel containing not more than 0.25%/ by weight of carbon, and wherein the maximum temperature of the composite wire reached in the heat treatment is within a range of 580-650.degree. C.