Characteristics of splat-cooled Sn- hbox{Bi}_{5} - hbox{Pb}_{bi x} alloys

A Sn-5 , wt.%Bi binary master alloy was prepared by melt spinning. Ternary alloys with different Pb contents ( x = 0 - 2.5,hbox{wt.}% ) were prepared with the same technique. All the alloys were irradiated with 1.2,hbox{MGy} gamma -radiation at room temperature. The internal friction, Q^{-1} , the thermal diffusivity D_{rm th} and the Young's modulus Y obtained by applying the resonance technique were measured at room temperature before and after irradiation. DTA thermograms and X-ray diffraction patterns were obtained for the tested alloys. The results showed a remarkable dependence on both the amounts of the ternary addition and irradiation with gamma -rays. The observed changes in the measured values were attributed to a composition inhomogeneity, caused by the distribution mode of the third element in the matrix and the defects induced by irradiation.