Sintered alloy article, its production method and a motorized fuel pump comprising a bearing comprised of sintered alloy article

Abstract

A sintered alloy article having superior corrosion resistance while also ensuring product dimensional accuracy is provided. A sintered alloy body is formed by molding and sintering (S 2 ) a raw material powder containing copper, and tin plating (S 4 ) treatment on this sintered alloy body is performed, followed by sizing (S 5 ). When the tin plating layer is compressed during sizing, the tin plating layer is formed to a nearly uniform thickness, pores opened in the outer surface of the sintered alloy body are blocked by the above tin plating, as a result of said tin plating being compressed by the above sizing. Moreover, by combining a copper-based sintered alloy and tin plating, a sintered body is obtained provided with both corrosion resistance to sulfur and its compounds as well as corrosion resistance to formic acid, acetic acid and other organic acids.

1 . A sintered alloy article obtainable by providing a tin plating layer on a sintered alloy body comprised by molding and sintering a raw material powder containing copper, and sizing said sintered alloy body having this tin plating layer.  
     
     
         2 . The sintered alloy article according to  claim 1  wherein, said sintered alloy article is a sliding member.  
     
     
         3 . A production method of a sintered alloy article comprising: forming a sintered alloy body by molding and sintering a raw material powder containing copper, and tin plating this sintered alloy body followed by sizing.  
     
     
         4 . A motorized fuel pump comprising a bearing composed of the sintered alloy article according to  claim 1.