Preparation method of high performance nanometer lanthanide oxide doped molybdenum-silicon-boron alloy

Abstract

The invention provides a preparation method of a high performance nanometer lanthanide oxide doped molybdenum-silicon-boron alloy. The preparation method comprises the following steps: molybdenum powder, silicon powder and boron powder are used as raw materials, different contents of nanometer lanthanide oxide are doped, the materials are mixed evenly through ball milling, prepressing and presintering are performed, the obtained sintered body is smelted in a vacuum arc furnace, the smelting working current is 800-1000A, the obtained alloy ingots are ground and subjected to ball milling to prepare powder, the alloy powder is sieved with a 200-300 mesh Tyler sieve, the obtained alloy powder is sintered in a vacuum hot-pressing sintering furnace at 1500-1700 DEG C and 30-50MPa for 1-3 hours,and the product is cooled to the room temperature along with the furnace after sintering. By adopting the method, the defects such as high sintering temperature, long time, inadequate reaction and more macro-defects, of the traditional powder metallurgy technology for preparing the molybdenum-silicon-boron alloy can be overcome; and the prepared nanometer lanthanide oxide doped molybdenum-silicon-boron alloy is characterized by uniform structure, high density and high strength.

Description

technical field [0001] The invention belongs to the technical field of powder metallurgy, in particular to a method for preparing a high-performance nanometer lanthanum oxide doped molybdenum-silicon-boron alloy. Background technique [0002] 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. The current research results show that molybdenum-silicon-boron alloy has the most potential to replace nickel-based superalloys due to its high melting point, good oxidation resistance and high temperature creep resistance, so molybdenum-silicon-boron alloy has also become the next generation The best candidate for high-temperat...

AI Technical Summary

Problems solved by technology

Due to the irregular shape of the alloy obtained by arc melting, and the serious composition segregation due to the general cooling of water-cooled copper molds, it leads to obvious macroscopic micro-cracks, which limits the application of this method.

The traditional powder metallurgy method also leads to uneven composition and insufficient reaction due to the limitation of its sintering temperature, which affects the mechanical properties and oxidation resistance of the alloy.

Although the plasma activation sintering method (SPS) shortens the sintering time, the engineering application of the material is limited due to the low sintering pressure and the small size of the prepared samples.