分别采用两种工艺制备的Fsss粒度相近的WC粉末为原料,在不同球磨时间下制备WC-10％Co-0.3％Cr3C2-0.5％TaC试样于l 450℃下烧结,对比两种合金的微观结构和常规性能.结果表明:采用粒度分布较窄、不含WC团聚颗粒的WC粉末为原料,经10 h球磨就能得到微观组织结构均匀的超细硬质合金;采用粒度分布较宽、含有大量WC团聚颗粒的WC粉末为原料,需要50 h球磨才能得到微观结构较为均匀的超细硬质合金,球磨时未被破碎的WC团聚颗粒烧结时会长大为WC晶粒团聚体,或者是粗大WC晶粒,会降低合金的抗弯强度值;原始粉末粒度组成对超细硬质合金的矫顽磁力、密度和硬度影响较小.
Using WC powder with similar Fsss particle size prepared by two kinds of processes,WC-10％Co-0.3％ Cr3C2-0.5％ TaC samples were prepared under different milling times and sintered at 1 450 ℃.Microstructures and conventional properties of the two alloys were compared.The results show that ultrafine cemented carbides with uniform microstructure can be obtained by 10 h ball milling using WC powder with narrow particle size distribution and no WC particle aggregates as raw material,but more than 45 h ball milling is needed to obtain ultrafine cemented carbides with relatively uniform microstructure by using WC powder with large particle size distribution and large amount of WC aggregate particles.The unbroken WC agglomerated particles during milling will grow up to WC grain aggregates or coarse grains when sintered,which will reduce the bending strength of the alloy.The particle size composition of original powder has little effect on coercive force,density and hardness of ultrafine cemented carbide.
参考文献
- 下载量()
- 访问量()
- 您的评分：
-
10%
-
20%
-
30%
-
40%
-
50%