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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%Cr_3C_2-0.5%TaC试样于1 450℃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。
The WC powders with the similar size of Fsss prepared by the two processes were respectively used as raw materials. WC-10% Co-0.3% Cr 3 C 2-0.5% TaC samples were sintered at 1450 ℃ with different ball milling time. Structure and conventional performance. The results show that WC powders with narrow particle size distribution and no WC agglomerates are used as raw materials. After 10 h milling, ultrafine cemented carbide with uniform microstructure can be obtained. WC powder as a raw material requires 50 h ball milling in order to obtain ultra-fine carbide with a uniform microstructure. The WC agglomerated particles, which are not broken during ball milling, grow into WC grain aggregates or coarse WC grains during sintering, Will reduce the bending strength of the alloy; the particle size of the original powder has little effect on the coercivity, density and hardness of the ultrafine cemented carbide.