Ni_3Al添加量对WC-Co硬质合金中WC晶粒形状的影响  

Effect of Ni_3Al Addition on WC Grain Shape in WC-Co Cemented Carbide

作　　者：龙坚战[1,2] 张忠健[1,2] 彭文[1,2] 陆必志[1,2] 周华堂[2] 罗海辉[2] 董亮[2] 

机构地区：[1]硬质合金国家重点实验室,湖南株洲412000 [2]株洲硬质合金集团有限公司,湖南株洲412000

出　　处：《硬质合金》2013年第6期308-315,共8页Cemented Carbides

基　　金：国家重点基础研究发展计划(973计划)2012CB723906资助项目

摘　　要：采用粉末冶金制备技术,以粗WC粉末、Co粉和WC+Ni3Al预合金粉末为原料制备出WC-40vol%(Co-Ni3Al)硬质合金。利用扫描电镜和透射电镜研究了不同Ni3Al含量对WC-40vol%(Co-Ni3Al)硬质合金中WC晶粒形状的影响规律。结果表明:W在Co粘结相中的固溶度接近25.4 wt%,而W在Ni3Al粘结相中的固溶度接近9.5 wt%,随着Ni3Al含量的增加,粘结相对W的固溶度减小,合金中的WC晶粒圆钝和细小;WC晶粒表面上出现明显的台阶。相应的,延长烧结时间,WC-Co-Ni3Al硬质合金具有与WC-Co硬质合金相同的WC生长行为,WC-40vol%(Co-Ni3Al)硬质合金中的WC晶粒表面上的台阶处出现明显的刻面。Using coarse WC powder, Co powder and WC＋Ni3Al alloy powder as raw material, WC-40 vol%（Co-Ni3Al） cemented carbide was fabricated by conventiona! powder metallurgy technology. The effect of Ni3A1 content on the WC grain shape in the WC-40 vol% （Co-Ni3Al） cemented carbide was investigated by using scanning electron microscope and transmission electron microscopy. The results show that, the solubility of W in the Co binder phase is close to 25.4 wt%, while that is 9.5 wt% in the Ni3Al binder phase. With the increase of Ni3Al content in WC-40 vol%（Co-Ni3Al） cemented carbide, the WC grains become rounder and finer, which is attributed to the lower solubility of W in binder. The surfaces of WC grains are strongly stepped, consequentially with the increase of sintering time, the steps are strongly micro-faceted. Similar WC grain growth behavior in WC-Co-Ni3Al cemented carbide as that in WC-Co cemented carbide is considered to be responsible for the appearance of the faceted WC shape in WC-40 vol%（Co-Ni3Al） cemented carbide.

关 键 词：WC形状 粉末冶金 NI3AL WC—Co 

分 类 号：TG135.5[一般工业技术—材料科学与工程]