Method For Manufacturing Metal Composite Sintered Body

Abstract

A method for manufacturing a metal composite sintered body includes: a molding step of injection-molding a first molded product and a second molded product from a kneaded product of a metal powder and a binder; an assembling step of fitting the first molded product to the second molded product without performing a solvent degreasing treatment to form a composite; and a heating step of subjecting the composite to a thermal degreasing treatment and a sintering treatment, in which the first molded product and the second molded product have fitting portions that fit to each other, at least one of the fitting portion of the first molded product and the fitting portion of the second molded product has a tapered shape, in the assembling step, a maximum meshing when the fitting portions are fitted to each other is 0.002 mm or more and 0.010 mm or less, and a content of the binder in the kneaded product is 2 mass % or more and 20 mass % or less with respect to a total amount of the kneaded product.

What is claimed is: 
     
         1 . A method for manufacturing a metal composite sintered body, comprising:
 a molding step of injection-molding a first molded product and a second molded product from a kneaded product of a metal powder and a binder;   an assembling step of fitting the first molded product to the second molded product without performing a solvent degreasing treatment to form a composite; and   a heating step of subjecting the composite to a thermal degreasing treatment and a sintering treatment, wherein   the first molded product and the second molded product have fitting portions that fit to each other,   at least one of the fitting portion of the first molded product and the fitting portion of the second molded product has a tapered shape,   in the assembling step, a maximum meshing when the fitting portion of the first molded product and the fitting portion of the second molded product are fitted to each other is 0.002 mm or more and 0.010 mm or less, and   a content of the binder in the kneaded product is 2 mass % or more and 20 mass % or less with respect to a total amount of the kneaded product.   
     
     
         2 . The method for manufacturing a metal composite sintered body according to  claim 1 , wherein
 a difference in gradient angles between the fitting portion of the first molded product and the fitting portion of the second molded product is 0.5° or more and 5.0° or less.   
     
     
         3 . The method for manufacturing a metal composite sintered body according to  claim 1 , wherein
 the fitting portion of the first molded product and the fitting portion of the second molded product are each provided with a positioning portion for preventing a deviation during fitting in the assembling step.   
     
     
         4 . The method for manufacturing a metal composite sintered body according to  claim 1 , wherein
 in the thermal degreasing treatment, heating at 400° C. or higher and 550° C. or lower is performed for 30 minutes or longer and 6 hours or shorter.   
     
     
         5 . The method for manufacturing a metal composite sintered body according to  claim 1 , wherein
 in the sintering treatment, heating at 900° C. or higher and 1500° C. or lower is performed for 30 minutes or longer and 8 hours or shorter.