化学共沉淀工艺对镍包覆碳化钨硬质合金粉体包覆质量的影响

Effects of Chemical Co-precipitation Process on Coating Quality of Nickel Coated Tungsten Carbide Cemented Carbide Powder

以碳化钨(WC)粉末和NiCl_(2)·6H_(2)O为原料,将化学共沉淀工艺和高温氢气还原工艺相结合制备了镍包覆WC复合粉体(WC-Ni)。对WC-Ni复合粉末的微观形貌、物相组成进行了表征与分析,研究了化学共沉淀工艺对镍包覆WC粉体包覆质量的影响。结果表明:在适当料液浓度、温度和沉淀剂加入体积流量条件下,通过调节晶粒成核速率、粒子间的碰撞几率和颗粒聚集程度,有利于获得分散均匀、包覆致密的WC-Ni粉末。优化工艺条件为0.4 mol·L^(-1) NiCl_(2)+0.2 mol·L^(-1)(NH_(4))_(2)C_(2)O_(4),反应温度50℃,沉淀剂加入体积流量0.17 mL·s^(-1)。

Using tungsten carbide(WC)powder and NiCl_(2)·6 H_(2)O as raw materials,nickel coated WC composite powder(WC-Ni)was prepared by combining chemical co-precipitation process and high temperature hydrogen reduction process.The micro morphology and phase composition of WC-Ni composite powder were characterized and analyzed.The effect of chemical co-precipitation process on the effect of nickel coated WC powder was studied.The results show that under the conditions of proper liquid concentration,temperature and precipitant addition volume flow,by adjusting the nucleation rate of crystal grains,the collision probability between particles and the degree of particle aggregation,it was beneficial to obtain uniformly dispersed and densely coated WC-Ni powder.The optimized process conditions were 0.4 mol·L^(-1) NiCl_(2)+0.2 mol·L^(-1)(NH_(4))_(2)C_(2)O_(4),the reaction temperature was 50℃,and the addition volume flow of precipitant was 0.17 mL·s_(-1).