M42高速钢粉末球磨工艺优化及其SPS烧结

The ball milling process optimization of M42 high speed steel powder and spark plasma sintering

利用高能球磨法制备了不同粒度的M42高速钢粉末,并对其进行了放电等离子烧结(SPS)。测试了粉末粒度分布,观察了粉末及其烧结试样的形貌,探讨了高能球磨M42高速钢粉体的球磨行为特征及烧结试样的显微组织与性能。结果表明:在球料比7∶1下,随球磨时间增加,粉末细化速率先快后慢,48h后趋于平缓,且粉末的团聚不断加剧;球磨48h的粉末经在温度970℃、压力70MPa下保持10min SPS烧结的M42粉末高速钢相对密度为98.99%,热处理硬度为67.4HRC;随粉末粒度的减小,其碳化物更加细小、均匀,由于粉末的团聚化,其相对密度不断降低,而粒度对硬度的影响不大。

The M42 high speed steel powder with different particle size was fabricated by high energy ball milling,and then sintered by spark plasma sintering（SPS）.The high energy ball milling process and SPS sintering behavior of M42 high speed steel powder were studied according to the observation of grain size and morphology of the powder and sintered specimen.The results show that with the ball milling time increasing,while the ball/powder weight ration7∶1,the average particle size decrease to an extremum after 48h then keep constant,and the reunion of the powder is increasing.Relative density of M42 PM high speed steel prepared from 48h ball milling powder with the SPS sintering process 970 ℃ × 10min×70MPa is 98.99%,and hardness is 67.4HRC after heattreatment.With the particle size decreasing,the carbide of M42 PM high speed steel is even smaller and uniform,relative density continuously decreas,while the parlicle size has little effect on its hardness due to reunion of powder.