Pb-FREE COPPER-BASED SINTERED SLIDING MATERIAL

Abstract

[Task] The adhesion resistance of Cu—Bi based or Cu—Sn—Bi based alloy is lower than that of Cu—Sn—Pb based alloy, and also since conformability of the former alloy is low. Therefore, when Bi of the former alloy adheres onto an opposite shaft, seizure of the former alloy is likely to occur as compared with the case of the latter Cu—Sn—Pb based alloy. In is alloyed in the Bi phase of the Cu—Sn—Bi—In based copper alloy. The In-alloyed Bi phase has a considerably low melting point and therefore the sliding properties deteriorate. [Means for Solving] A Pb-free copper-based sintered sliding material has a composition that 0.5 to 15.0 mass % Bi and 0.3 to 15.0 mass % In, with the balance being Cu and inevitable impurities. With regard to the existence of Cu, Bi, and In, the material consists of a Cu matrix containing In, a Bi phase, and an In concentrated region in said Cu matrix at a boundary of said Bi phase.

1 . A Pb-free copper-based sintered sliding material containing 0.5 to 15.0 mass % Bi and 0.3 to 15.0 mass % In, with the balance being Cu and inevitable impurities, characterized by the existence of Cu, Bi, and In in the material as follows, namely, a Cu matrix containing In, a Bi phase, and an In concentrated region in said Cu matrix at a boundary of said Bi phase. 
   
   
       2 . A Pb-free copper-based sintered sliding material according to  claim 1 , characterized in that said material further contains 0.5 to 15.0 mass % Sn, and the total content of In+Sn is 1.0 to 15.0 mass %. 
   
   
       3 . A Pb-free copper-based sintered sliding material according to  claim 1  or  2 , characterized in that said material further contains 0.5 mass % or less P and 0.1 to 5.0 mass % Ni. 
   
   
       4 . A Pb-free copper-based sintered sliding material according to  claim 1 , characterized in that hard particles of an iron-based-compound, such as Fe 2 P, Fe 3 P, FeB, Fe 2 B, and Fe 3 B, is contained in an amount of 0.1 to 10.0 mass % relative to 100 mass % of said iron-based sintered sliding material. 
   
   
       5 . A Pb-free copper-based sintered sliding material according to  claim 1 , characterized in that a solid lubricant is contained in an amount of 5.0 mass % or less relative to 100 mass % of said iron-base sintered sliding material.