Method for producing titanium alloy sintered part, and titanium alloy sintered part

Abstract

There is provided a titanium alloy sintered part in which the oxygen content is reduced and the fatigue strength is enhanced, and a method for producing the titanium alloy sintered part. The method for producing a titanium alloy sintered part by a metal injection molding method includes a mixing process of producing a compound of a metal powder and a binder, an injection process of subjecting the compound to injection molding to produce a green part, a degreasing process of degreasing the green part to remove the binder, and a sintering process of sintering the green part from which the binder was removed to obtain a sintered body, and the sintering process is performed at a sintering temperature of 800 to 995° C. for a sintering time of 6 to 200 hours.

1 . A method for producing a titanium alloy sintered part by a metal injection molding method, comprising:
 a mixing process of producing a compound of a metal powder and a binder;   an injection process of subjecting the compound to injection molding to produce a green part;   a degreasing process of degreasing the green part to remove the binder; and   a sintering process of sintering the green part from which the binder is removed to obtain a sintered body,   wherein the sintering process is performed at a sintering temperature of 800 to 995° C. for a sintering time of 6 to 200 hours.   
     
     
         2 . The method for producing a titanium alloy sintered part according to  claim 1 ,
 wherein the sintering process is performed under vacuum, and   in the vacuum, an atmospheric pressure during sintering is 1×10 −3  Pa or less.   
     
     
         3 . The method for producing a titanium alloy sintered part according to  claim 1 ,
 wherein a low-oxygen metal powder is used as the metal powder.   
     
     
         4 . A titanium alloy sintered part, consisting of, in mass %,
 aluminum: 5.50 to 6.50%,   vanadium: 3.50 to 4.50%,   iron: 0.40% or less,   oxygen: 0.2% or less,   carbon: 0.08% or less,   nitrogen: 0.05% or less, and   hydrogen: 0.015% or less,   with the balance being titanium,   and having a relative density of 97.0% or more.   
     
     
         5 . The titanium alloy sintered part according to  claim 4 ,
 wherein a mean grain size is 5.0 to 50.0 μm, and
 a aspect ratio of a crystal structure is 3 or less.