摘要
The morphologies and formation process of Ni-pool defects in WC?8Ni cemented carbides were studied. The SEM images show that Ni-pool generally has two kinds of morphologies: “island” in isolation and “ring” around a new phase. In the obtained samples with “ring-like Ni-pool”, WC, Ni and Ni2W4C (η phase) phases were detected in XRD patterns. Combined with SEM, EDX and XRD results, it is found that the phase in the center of the “ring-like Ni-pool” is Ni2W4C (η phase) and the main chemical components of Ni-pool are Ni, W and C. In addition, the relationships among large size Ni (agglomerated) particles, volatile impurities, pores and carbon content vs forming process of the Ni-pool defects for WC?8Ni cemented carbides are also presented and discussed.
研究WC-8Ni合金中Ni池缺陷的形貌与形成过程。SEM观察结果显示,合金中Ni池的形貌主要有两种,"孤岛状"和"环装"。XRD检测结果表明,在"环装"Ni池缺陷中,存在WC、Ni和Ni_2W_4C(η相)3种物相。综合SEM、EDX及XRD结果分析发现,"环装"Ni池缺陷中心为Ni_2W_4C相,而Ni池的主要成分为Ni、W和C。另外,对Ni池缺陷的形成与团聚大尺寸Ni颗粒、可挥发性杂质、孔隙及碳量之间的关系进行讨论。
