Hardness of the solder alloy Cu-In-Sb in dependence of the molar ratio of the components

Abstract

An increasing concern for environmental protection led to the establishment of strict provisions regarding the use of alloys that could have a detrimental effect on the environment, which resulted in reduction of use lead solder materials. Copper-based alloys in particular represent a possible replacement for standard not-lead solder.  Alloys on the basis of copper, indium, and antimony are important in production of new solder materials. Thus, it is desirable the knowledge about different ratios of mentioned elements in these alloys, related to their influence on the mechanical properties of alloy, for the development of new high quality solder materials. In this paper, the hardness of ternary system Cu-In-Sb was investigated, for three vertical cross sections with molar ratio: Sb:Cu = 1, Cu:In =  1, Sb:In = 1. Highest hardness has been found with 0,30 mol fraction of copper in Cu-InSb  vertical cross section. Hardness continually decreases with the increas of molar percent of antimony. Indium has shown the least variation and influence on the hardness of these alloys. The most variation in hardness was during the change of the molar fraction of copper, which indicates that the copper is the most important element for the hardness of this system.