Preparation method of micro-lanthanum-doped high-temperature molybdenum wire

Abstract

The invention belongs to the technical field of preparation of high-temperature molybdenum wires, and particularly relates to a preparation method of a micro-lanthanum-doped high-temperature molybdenum wire. The preparation method of the micro-lanthanum-doped high-temperature molybdenum wire comprises the following steps: S1, carrying out spray doping on a mixed solution of ammonium molybdate andrare earth lanthanum nitrate according to the ratio of rare earth oxide 0.3-0.5% La2O3 to obtain a mixture A; S2, heating and decomposing the mixture A prepared in S1, and preparing molybdenum powderof uniformly doped rare earth lanthanum oxide meeting certain requirements through a two-stage reduction process; and S3, sequentially carrying out sieving, powder mixing, cold isostatic pressing, presintering and intermediate frequency sintering processes on the molybdenum powder of the uniformly doped rare earth lanthanum oxide prepared in S2 to obtain a billet. The preparation method of the micro-lanthanum-doped high-temperature molybdenum wire has reasonable design, and is economical and energy-saving; the micro-lanthanum-doped high-temperature molybdenum wire with uniform materials and high yield can be obtained by adjusting and improving the process and equipment of the micro-lanthanum-doped high-temperature molybdenum wire, and the high-temperature use performance of the micro-lanthanum-doped high-temperature molybdenum wire is improved effectively.

Description

technical field [0001] The invention relates to the technical field of preparation of high-temperature molybdenum wires, in particular to a preparation method of micro-doped lanthanum high-temperature molybdenum wires. Background technique [0002] Molybdenum and molybdenum alloy wire have the advantages of high melting point, high temperature strength, good electrical and thermal conductivity, low expansion coefficient, good corrosion resistance and chemical stability, so they are used in the electronics industry, chemical industry, metallurgical industry and aerospace industry All have a wide range of applications, mainly used in the electric light source and electric vacuum industry as electric light bulbs, thermal body brackets, electron tube grids, launch tubes, and cathodes of secondary rectifier tubes, and in the machining industry for EDM. At the same time, molybdenum wire is also an excellent high-temperature material, which has been widely used to manufacture vacuu...

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Problems solved by technology

Studies have shown that doping rare earth oxide La in molybdenum 2 o 3 It can improve the microstructure of molybdenum, after molybdenum recrystallization is completed at high temperature, La 2 o 3 Particles have the effect of hindering the transformation of recrystallized grains to equiaxed grains, making them form large and long dovetail-shaped grain structures overlapping each other after recrystallization, and at the same time due to La 2 o 3 It absorbs oxygen in molybdenum, slows down the segregation of oxygen at the grain boundary, and strengthens the grain boundary, thereby improving the room temperature brittleness of molybdenum and reducing the plastic-brittle transition temperature, so the high temperature performance of La-Mo wire is greater. However, the existing process of micro-doped lanthanum high-temperature molybdenum wire is relatively cumbersome, resulting in low production efficiency of micro-doped lanthanum high-temperature molybdenum wire. Therefore, a preparation method for micro-doped lanthanum high-temperature molybdenum wire is proposed.

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