Precipitation hardening in lead-cadmium-calcium alloys is a two stage process : the first stage is a discontinuous hardening transformation without precipitation, the second stage is a discontinuous lamellar precipitation of Pb_3Ca. In order to increase the mechanical and electrochemical properties of these alloys, we have studied the influence of minor additions of tin on the precipitation hardening behaviour of PbCaCd alloys, as this element is used to improve the electrochemical properties of positive battery grids. The objective was to investigate in a systematic manner the ageing and overageing behaviour of PbCdCaSn alloys in the case of two different structural states: as-cast condition, rehomogenized state.
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