Preparation of nano rare-earth oxide doping molybdenum alloys

Abstract

The invention discloses a method for preparing a nano rare earth oxide doped molybdenum alloy. In the method, by taking rare earth ammonium dimolybdate crystals as raw materials and adopting the roasting and hydrogen reduction method, molybdenum alloy powder is obtained, the powder after reduction is in press-forming by the isostatic cool pressing with a pressure of between 180 and 200 Mpa, the formed blank materials are presintered in a muffle furnace with a temperature of between 1, 100 and 1, 300 DEG C, and sintered in a vacuum intermediate frequency induction sintering furnace at a temperature of between 1, 600 and 1, 900 DEG C for 10 to 24 hours; the materials sintered can be made by the prior mechanical processing methods into materials and products with different shape such as molybdenum alloy bar materials or plate materials, etc. as required. The molybdenum alloy containing nano rare earth oxide, prepared by the method of the invention, has the advantages of high intensity, ductility and toughness and wide application.

Description

technical field [0001] The invention relates to a preparation method of a rare earth oxide doped molybdenum alloy material, in particular to a preparation method of a nanoscale rare earth oxide doped molybdenum alloy material. Background technique [0002] Molybdenum metal materials do not have the property of crystallographic phase transition due to temperature changes, but have the intrinsic characteristics of ductile-brittle transition and low-temperature brittleness inherent in body-centered cubic metals. Therefore, how to further improve the toughness of molybdenum metal materials to improve their machinability has become the key to the development of molybdenum metal deep-processing products and to expand their application fields! In the late 1980s, Japan, Germany, Austria, China and other countries almost simultaneously started the research on molybdenum alloys with rare earth oxide liquid-solid doping (rare earth nitrate solution sprayed in solid molybdenum oxide pow...

AI Technical Summary

Problems solved by technology

However, the current traditional preparation technology of doped molybdenum alloy is difficult to meet this demand.

[0004] Currently, there are three commonly used preparation methods for oxide-doped molybdenum alloys: solid-solid doping method, liquid-solid doping method and liquid-liquid doping method. Among them, the solid-solid doping method has the advantages of simple operation and easy industrialization. The uniformity of the doped rare earth oxide distribution is poor and it is easy to bring in impurity elements, which leads to the failure of the performance of the prepared molybdenum material to meet the ideal requirements.

The liquid-solid doping method is currently widely used in industrial production. Although the uniformity of phase dispersion has been greatly improved, the degree of uniformity is still not ideal, especially the size of rare earth oxides is difficult to control. The refinement of alloy grains is not obvious and it is difficult to avoid the introduction of interstitial impurity elements, so it is difficult to obtain high-performance molybdenum alloy materials

Molybdenum alloy obtained by liquid-liquid doping method has the best effect of uniform distribution of doped second-phase particles. The process is complicated, and the size of the second phase particles in the obtained molybdenum alloy products is difficult to control, which is basically on the order of microns, and it is difficult to obtain evenly distributed nano-scale second phase particles, which limits the preparation of high-performance molybdenum alloy materials. Technological breakthroughs have restricted the development and wide application of high value-added molybdenum alloy deep-processing products that are urgently needed by the market