A kind of preparation method of agglomerated sintering type thermal spraying tungsten powder

Abstract

The invention discloses a manufacture method for glomerate sintered-type thermal spraying tungsten powder. The manufacture method comprises the following steps: firstly, tungsten powder with the Fisher particle size of 0.8-30 mu m is selected as a raw material; then poval, polyethylene glycol and polyvinyl pyrrolidone are weighed and uniformly mixed with deionized water to prepare a moulding agent solution; the deionized water, the tungsten powder and the moulding agent solution are placed in a ball mill for ball milling activation according to a mass ratio of (10-20%):1:(3-10%); after the mixture is ball milled uniformly, tungsten powder suspension slurry is prepared; the prepared tungsten powder suspension slurry is placed into a spray drying tower; spray drying granulation is adopted to obtain tungsten powder particles; the manufactured tungsten powder particles are placed in a vacuum sintering integral furnace for sequentially performing degreasing and sintering; and then the sintered tungsten powder is ball milled and separated to obtain the product. The tungsten powder manufactured with the manufacture method is controllable in particle size distribution, high in sphericity degree, good in fluidity, low in impurity content, good in abrasion resistance, low in manufacture cost and applicable to industrial production.

Description

technical field [0001] The invention relates to the technical field of surface engineering and remanufacturing, in particular to a preparation method of agglomerated and sintered thermal spray tungsten powder. Background technique [0002] Thermal spraying technology is a rapidly developing surface strengthening technology. It uses special equipment to heat metal or non-metallic materials to a molten or semi-melted state by using a heat source, and sprays it onto the surface of the workpiece with a high-speed airflow to form a coating to improve the wear resistance and corrosion resistance of the workpiece. [0003] Tungsten has the advantages of high melting point, excellent high temperature strength, good corrosion resistance, good thermal conductivity, small thermal expansion coefficient, high elastic modulus and strong ability to absorb rays, and is widely used in aviation, aerospace, military industry and electronics industry. Among them, thermal spraying tungsten powd...

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Problems solved by technology

It has been reported that ammonium paratungstate reduction was used to prepare ultra-coarse spherical tungsten powder, although the coarse-crystalline ammonium paratungstate powder was obtained by adding alkali metal salt to ammonium tungstate, and then the coarse-grained tungsten powder was prepared (Xin Yanjun, Guo Zhimeng, Luo Ji, Wang Ruixin, Fang Zhecheng. Ammonium paratungstate reduction to prepare ultra-coarse spherical tungsten powder), the product has less impurity content and high purity, but its parameters are not easy to control, the particle size range is difficult to control and adjust, and its fluidity is poor, so it is not suitable for industrial production of thermal spraying tungsten powder

[0005] Some scholars have studied the shaping treatment of granular tungsten oxide, after sieving treatment, reducing the shaped tungsten oxide powder in a reducing atmosphere, and obtaining nearly spherical tungsten powder particles after cooling (Jia Chengchang, Wang Congcong, Liang Dong, Gao Peng, Cui Zhaowen, Chang Yuhong. A method for preparing nearly spherical tungsten powder. CN201310042633.4), but the prepared tungsten powder is spherical in shape and has a single particle size range

[0006] There is also the use of plasma spheroidization technology to prepare spherical tungsten powder for thermal spraying. In this method, ordinary tungsten powder is added to the plasma jet to melt the surface or the whole of the tungsten powder particles to form molten droplets. The molten droplets shrink into a spherical shape due to surface tension, and then pass through Rapid cooling to obtain spherical tungsten powder, although this method can prepare thermal sprayed tungsten powder with high particle surface finish, increased density, reduced brittleness and good fluidity (Hou Yubo, Zeng Keli, Yu Yueguang, Ren Guangjing, Xu Genguo , Ma Jianghong. Plasma spheroidized tungsten powder. Nonferrous Metals, 2008.60(1):41,43) (Guo Shuangquan, Ge Changchun, Feng Yunbiao, Zhou Zhangjian. Process research on preparation of spherical tungsten powder for thermal spraying by low-cost plasma spheroidization technology. Powder metallurgy Industry, 2010.20(3):1,4), but the equipment of this method is expensive, the energy consumption is high, the preparation cost is high, and the tungsten powder is oxidized during the spheroidization process, so it is difficult to realize industrial production and application

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