With the rapid development of science and technology, modern industry and some high-end applications have put forward an increasingly urgent demand for new materials with high temperature resistance, oxidation resistance and corrosion resistance. Iridium (Ir) belongs to the pge, melting point 2447 ℃, with a strong corrosion resistance and high thermal stability, rhodium melting point is 1963 ℃, after in the pge iridium, osmium, lattice constant of the two close, can form a solid solution. All over the whole composition range to join in iridium rhodium can greatly improve the high temperature oxidation resistance of iridium, so the iridium rhodium is ideal material under the condition of the ultra high temperature applications. Hot isostatic pressing process is a powder metallurgy new technology developed in recent decades, in the near net shape and hard processing material has the advantages of other processing methods don't have parts with uniform organization resulting from the processing It is widely used in aerospace and other special fields. This paper adopts the first principles method based on density functional theory to study Rh content on the Ir - Rh alloy mechanical properties and combined with the influence of iridium rhodium oxide of the results of Ir - filtered Rh alloy composition. The theoretical calculation results show that strength and hardness of the Ir - Rh alloy increases quickly with the increase of Rh content, after reaching a maximum at Ir - 10 Rh falling fast to Ir - 40 first slowly rising again after a slight decline in Rh. Rh add will cause the embrittlement of iridium rhodium, the brittleness size with the increase of Rh content increased after the first decreases, and reached the highest in Ir - 50 Rh places. High temperature oxidation resistance of iridium rhodium increased with the increase of Rh content Strong, this is because the Rh elements can reduce high temperature alloy oxide volatile, so as to reduce its under the condition of high temperature oxidation weightless, strengthen its high temperature oxidation resistance. Considering theoretical calculation and experimental results, the oxide choose Ir - 20 Rh as hot isostatic pressing technology research of alloy elements.
The design of different blending process and degassing process research blending time, balls, in addition to the temperature effect on the properties of metal powder, finding the best mixed powder and degassing process. By cold isostatic pressing, sintering, hot isostatic pressing process routes of the preparation of iridium rhodium, and under different temperature and pressure of hot isostatic pressing to get the density of the iridium rhodium Degree and microstructure analysis and characterization. In iridium rhodium by blending experiments, found the ball to mix the powder mixture of time required to reach even than the ball by blending time is short, two kinds of process of the mixed powder oxygen content quite and basically the same. The ball of metal powder mixed nitrogen content than the ball mix a little higher, but after degassing process can reduce to less than 0.001%. So the blending process to choose the ball mix 1 oh. After 2 h at 1200 ℃ in addition to gas, then the temperature to 1800 ℃ sintering. With the increase of hot isostatic pressing temperature and pressure, the alloy density will be increased, but because of For the limitation of enveloping materials, the density can only reach 95.7% of the theoretical density after using the highest temperature (1300℃) and the highest pressure (140MPa) thermal isostatic pressure for 2h, and can be increased to the theoretical value by repressing at a higher temperature.
