High-density iridium alloy billet and preparation method of the high-density iridium alloy billet

Abstract

The invention discloses a high-density iridium alloy billet and a preparation method of the high-density iridium alloy billet. The high-density iridium alloy billet contains 0.1%-0.5% of tungsten by weight, 40ppm-80ppm of thorium, and the balance of iridium and unavoidable impurities. The preparation method includes the steps as follows: according to the requirement for the components of the final iridium alloy billet, conducting high energy activation on tungsten powder, tungsten-thorium alloy powder and iridium powder by adopting a high-energy ball mill, uniformly mixing the tungsten powder, the tungsten-thorium alloy powder and the iridium powder, then placing the mixed powder into a vacuum oven to dry so as to obtain a high-energy activated mixed powder, later pressing and moulding the high-energy activated mixed powder in a mould pressing or cold isostatic pressing way to botain a powder pressed billet, then placing the powder pressed billet in a high-temperature sintering furnace to sinter, and cooling along with the furnace to obtain the high-density iridium alloy billet. In the invention, high-energy ball milling activation and mixing in batches are adopted, thus achieving the uniform distribution of trace thorium in the alloy powder and reducing sintering activation energy; and the high-density iridium alloy billet which meets the requirements of an iridium alloy applying piece and follow-up hot working on the density of the billet is prepared, and the relative density achieves above 95%.

Description

technical field [0001] The invention belongs to the technical field of alloy preparation, and in particular relates to a high-density iridium alloy billet and a preparation method thereof. Background technique [0002] Iridium and its alloys have been highly concerned by researchers at home and abroad. In 2005, "Science" magazine reported the cause and mechanism of brittle cleavage of iridium. The United States, Japan, Russia and other countries are competing to carry out processing such as iridium alloy smelting and hot extrusion. Aspects of preparation research. [0003] Due to its excellent properties such as oxidation resistance, corrosion resistance, and high-temperature strength, iridium alloys have been widely used in advanced engines, thermoelectric batteries for space environments (nuclear fuel sealing materials), supersonic wind tunnel nozzles, and high-temperature temperature measurement protective sleeves. Since the 1960s, the United States has vigorously carrie...

AI Technical Summary

Problems solved by technology

However, because iridium has the characteristics of low activity, high melting point, and rapid thermal hardening, it is difficult to sinter and densify by conventional powder metallurgy. Direct sintering makes it difficult for the blank to reach a density of more than 90%. The density must reach more than 94%, and the conventional powder metallurgy method cannot meet the actual needs