The paper describes investigations of the dependence of resistance and strength properties of Au -Al joints on the kind of additive to gold and the ageing time at 200°C. Gold was doped with Ag, Cu, Pd or Pt additives. The ageing process caused intermetallic compounds formation at the border between Al wire and Au alloy substrate. The effect of intermetallic phases growth was analysed by metallographic and SEM/EDX examinations. The great resistance increase was observed in the case of pure Au or Pt doped substrates. The strongest joints were obtained on Au doped with Cu or Pd while the lowest resistance was reached for Ag doping. Ag, Cu or Pd additive to Au clearly inhibited Au -Al joint failure due to reactions taking place in the phase transformation zone.
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