Method for preparing alloy nano rare-earth oxide doping molybdenum-silicium-boron alloy

Abstract

The invention discloses a method for preparing a molybdenum-silicon-boron alloy doped with a nano rare earth oxide, which comprises the steps that: rare earth ammonium dimolybdate is taken as raw material, molybdenum alloy powder containing the rare earth oxide is obtained by adopting methods of roasting and hydrogen reduction, silicon powder and boron powder are added into the molybdenum alloy powder, ball grinding processing is carried out, and then hot pressed sintering is carried out in a vacuum hot pressed sintering furnace so as to lead the densification of the powder, wherein, the sintering temperature is 1600 to 1800 DEG C, the sintering pressure is 45 to 55MPa and the sintering time is 5 to 10 hours. The preparing method is simple and practicable, the size of the rare earth oxideparticles in the prepared molybdenum-silicon-boron alloy is tiny, the average particle size is smaller than 100nm, and the prepared molybdenum-silicon-boron alloy has the advantage of high strength.

Description

A kind of preparation method of nano rare earth oxide doped molybdenum-silicon-boron alloy technical field The invention belongs to the technical field of powder metallurgy, and in particular relates to a preparation method of a molybdenum-silicon-boron alloy doped with nanometer rare earth oxides. Background technique In recent years, with the rapid development of the aerospace and national defense industries, higher and more stringent requirements have been put forward for the high-temperature mechanical properties and oxidation resistance of high-temperature structural materials. The limitation (the maximum service temperature cannot exceed 1100 ℃) has become a bottleneck restricting the development of related industries. Therefore, scientists from various countries have accelerated the research progress on the next generation of high-temperature structural materials. The current research results show that the molybdenum-silicon-boron alloy composed of three phases of M...

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Problems solved by technology

The molybdenum-silicon-boron alloy composed of three phases of Mo, Mo3Si and Mo5SiB2 endows the alloy with good high temperature oxidation resistance due to the existence of the Mo5SiB2 phase. Although the existence of the Mo phase can ensure that the alloy has good toughness, but Since Mo does not have the property of crystallographic phase transition due to changing temperature, but has the intrinsic characteristics of ductile-brittle transition and low-temperature brittleness inherent in body-centered cubic metals, how to further improve and enhance the toughness of molybdenum-silicon-boron alloys to Improving its machinability becomes the key to develop molybdenum-silicon-boron alloy deep-processing products and expand its application field! At the same time, the problem of insufficient strength of Mo metal itself also restricts the expansion of the high-temperature application field of molybdenum-silicon-boron alloys to a certain extent.