球磨WC-8Co粉末的放电等离子烧结

对WC-8Co粉末不同球磨时间后进行放电等离子烧结,研究了球磨时间及烧结温度对WC-8Co硬质合金微观结构及性能的影响。结果表明:球磨时间延长,粉末颗粒变细,晶格畸变增加,衍射峰强度降低,并随时间延长,团聚现象严重;采用放电等离子烧结,在1 200℃时,可以得到接近全致密的烧结样品,烧结温度低于传统方法的烧结温度;球磨时间在2 h以下时,样品的致密度、硬度和断裂韧性达到最佳,晶粒较小且分布均匀;延长球磨时间,性能显著下降且出现较多粗晶、空洞、Co池等缺陷。

Spark Plasma Sintering of Milled WC-8Co Powder

WC-8Co powders with different milling time were sintered by spark plasma sintering at the different temperature.The influence of the milled time and sintering temperature on the microstructure and mechanical properties of hard alloy were investigated.The results showed that when the milling time was prolonged,the powder particles became smaller,the lattice distortion of WC grain increased,and the diffraction peak intensity decreased.Meanwhile,the longer milling time was,the more the aggregated powders were.The sintered samples can be close to full density using spark plasma sintering at 1 200 ℃,which was lower than the sintering temperature of traditional method.When the milling time was 2 h,the density,hardness and fracture toughness of the sintered samples were best,and the grain was smaller and evenly distributed.When the milling time was 4 h,the properties deteriorated rapidly,and the microstructure existed more coarse grains,pores,Co pools and other defects.