WC粒度对WC/10Co注射成形工艺的影响

研究了不同粒度的WC粉末对WC/10Co注射成形工艺(PIM)的影响,分析了WC粒度对喂料流变性、注射坯质量、脱脂工艺和烧结工艺的影响机理。结果表明:WC粒度越小,WC/10Co喂料流变性越差,注射坯质量越低,溶剂脱脂速率越高,合金形状偏差越大。超细WC/10Co喂料存在粉末团聚颗粒、粘结剂包裹不充分,其热稳定性低、流动性降低56%,注射坯致密度下降5%;超细WC-10Co合金的线收缩率达到20.80%,尺寸偏差为2.85%,脱脂-真空烧结时易出现脱碳现象。

Effects of WC Particle Size on WC/10Co Injection Molding Process

The effects of different WC particle sizes on WC/10 Co injection molding process(PIM)were investigated.The influence mechanisms of WC particle size on feedstock flowability,molded compact’s quality,degreasing process and sintering process were analyzed.The results show that as the WC particle size decreases,the flowability of WC/10 Co feedstock,the molded compacts’quality and the dimensional accuracy decrease,while only the solvent degreasing rate increases.For the ultrafine WC/10 Co feedstock with powder agglomerated particles and insufficient binder coating,the heat stability is lower and the flowability reduces by 56%,which reduced the density of molded compacts by 5%.As to as-sintered ultrafine WC-10 Co which is prone to be decarburization during degreasing-vacuum sintering,the line shrinkage is 20.80%and the dimensional deviation is 2.85%.