Experimental Study of the Phase Relations in the Ternary Gold-Palladium-Titanium and Gold-Rhodium-Titanium Systems at 1000°C

The isothermal section of the ternary systems gold-palladium-titanium and gold-rhodium-titanium at 1000°C was studied using the diffusion couple technique. These alloying systems are relevant for various technical applications, as functional materials for example high temperature shape memory alloys (HTSMAs), brazing filler metals, luxury items or biomedical implants. The research presents, for the first time, a comprehensive determination of phase relations and tie-triangles in these systems, identifying solid solubility of the various intermetallic compounds (IMC). The binary IMC of gold and palladium with titanium show a large solubility of the third alloying element, where gold and palladium replace each other at fixed titanium content. A complete solid solubility was observed between TiAu 2 and α-Pd 2 Ti. The binary phases with B2 structure form a large single phase field with (β-titanium) that surrounds the phase field of Ti 3 Au. Moreover, this research sets the groundwork for further investigations into these alloys, recommending specific sample compositions for future studies to refine understanding of phase boundary definitions.