Abstract
In our investigation of the AgCu25Zn20Cd20 alloy, cadmium was partly or fully replaced by indium and tin due to its toxicity. The influence of this substitution on the fraction, morphology and distribution of the identified phases has been examined. Beside αAg and αCu the intermetallic phases of β-AgCd(Zn), β-CuSn and δ-CuIn have been established after annealing of the alloys at 500 °C for 300 hours by X-ray phase analysis. The presence of the β-CuSn phase shows the influence of indium on the stability of that phase at lower temperatures. By microanalysis the distribution of metals in the present phases has been qualitatively determined. The influence of indium and tin on the liquidus and solidus temperatures is similar to that of the substitution of cadmium only by indium. Measured hardness of the cast alloys shows the favourable influence of the common substitution with indium and tin in comparison with substitution with one metal only.

Key words
soldering, silver solders, intermetallic compounds, phase diagrams, precious metal, indium, tin

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