Effect of Zr on microstructure and mechanical property of dispersion-strengthened Pt-20Rh

Dispersion-strengthened Pt-20Rh was designed and prepared by powder metallurgy-internal oxidation-sintering. After rolling and annealing, the microstructures, mechanical properties at room temperature and 1000 °C were tested and analysed. Results indicate that the dispersion-strengthened Pt-20Rh alloy consists of Pt and Rh solid solution, Y2O3 and ZrO2. It has a stabilised grain structure at 1000 °C. As the Zr content increases, the strengths at room temperature and high temperature are greatly improved. ZrO2 particles can pin up and block the movement of dislocations, making it possible to enhance the strength. When Zr content is 0.3 wt-%, the room temperature and 1000 °C tensile strengths are up to their maximum, i.e. 555 and 149 MPa, respectively.