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本文以WC-36%Ni3Al(文中百分含量如无特殊说明,均为体积分数)合金体系为研究对象,采用传统粉末冶金方法制备出WC-36%Ni3Al和WC-36%Co复合材料,用带能谱分析的扫描电子显微镜观察试样腐蚀后的区域,用EDS检测粘结相的化学组成,采用透射电子显微镜在高倍条件下观察WC形貌特征,研究了2种不同粒度WC在Ni3Al液相基体中的晶粒长大行为。结果表明,在碳饱和条件下烧结后,粗细WC晶粒表面都出现了明显的刻面台阶;细粒度WC晶粒的异常长大得到抑制,这与WC在Ni3Al基体中的低溶解度有关。由于WC晶粒的两个惯习面具有不同的表面能,随着烧结时间的延长,粗粒度WC晶粒平均粒径不断增大且发生取向生长而形成了粗大的WC。
The WC-36% Ni3Al and WC-36% Co composites were prepared by conventional powder metallurgy method using WC-36% Ni3Al alloy (volume percentage unless otherwise stated) Scanning electron microscope (EDS) with energy spectrum analysis was used to observe the corrosion area of the sample. The chemical composition of the binder phase was detected by EDS. The morphology of the WC was observed by transmission electron microscope at high magnification. Grain growth in phase matrix. The results show that there is a clear facet step on the surface of coarse and fine WC grains after sintering under carbon saturation condition. The abnormal growth of fine grain WC grains is restrained, which is related to the low solubility of WC in Ni3Al matrix. Due to the different surface energies of the two conventional WC grains, the average grain size of the coarse grain WC grains increases with the sintering time, and the coarse WC grains are formed by the orientation growth.