New types of lead-free solders on the base of tin and their properties

Abstract

The aim of the work is an experimental study of binary, ternary and quaternary systems on the base of tin alloys. 22 alloys with different ratios of individual elements Ag, Cu, In, Sb, Bi, and Sn were prepared experimentally. In addition, 6 alloys of lead-free solders produced commercially (Kovohute Pribram nastupnicka, a.s.) were used and the Pb-Sn solder served as a comparative etalon. The following characteristics were studied: temperatures and enthalpies of phase transformations (DTA, TG, DSC) of individual solders at the rates of re-heating and cooling of specimens of about 4 °C min-1, microstructural analysis (optical metallography) and microhardness of specimens, chemical analysis, microanalysis of individual phases in the structure of solders (WDX, EDX), measurement of surface tension and density of solders in dependence on the temperature, test of wettability with or without use of fluxes, measurement of corrosion properties, measurement of electrical resistivity.