Lead-free alloys containing various amounts of zinc (4.5%, 9%, 13%) and constant copper addition (1%) were discussed. The results of
microstructure examinations carried out by light microscopy (qualitative and quantitative) and by SEM were presented. In the light
microscopy, a combinatorial method was used for the quantitative evaluation of microstructure. In general, this method is based on the
phase quanta theory according to which every microstructure can be treated as an arrangement of phases/structural components in the
matrix material. Based on this method, selected geometrical parameters of the alloy microstructure were determined. SEM examinations
were based on chemical analyses carried out in microregions by EDS technique. The aim of the analyses was to identify the intermetallic
phases/compounds occurring in the examined alloys. In fatigue testing, a modified low cycle fatigue test method (MLCF) was used. Its
undeniable advantage is the fact that each time, using one sample only, several mechanical parameters can be estimated. As a result of
structure examinations, the effect of alloying elements on the formation of intermetallic phases and compounds identified in the examined
lead-free alloys was determined. In turn, the results of mechanical tests showed the effect of intermetallic phases identified in the
examined alloys on their fatigue life. Some concepts and advantages of the use of the combinatorial and MLCF methods in materials
research were also presented.