两相WC-Ni硬质合金的成分和结构

Composition and Microstructure in Two-phase WC-Ni Cemented Carbide

探讨了两相WC-Ni硬质合金的成分与合金密度和比磁饱和间及WC晶粒邻接度与其他显微结构参数间的定量关系。结果表明,单用磁饱和测定值难以确定合金成分,用密度测定值能精确计算确定牌号的两相WC-Ni合金的成分;用WC晶粒邻接度(或γ相平均自由程)、γ相体积分数和WC相平均晶粒尺寸中任意两个参数都能精确表征两相WC-Ni合金的结构特征,由此可定量评价WC晶粒邻接度对力学性能的影响程度;合金的维氏硬度既可用关于WC相和γ相原位硬度的混合物规则也可用与WC晶粒邻接度的正向对应关系或与γ相平均自由程的反向Hall-Petch型关系式精确表征。

The quantitative experimental relationships of the composition parameters with the alloy density and the specific saturation magnetization and the relations of the WC grain contiguity Cwc with other microstructure parameters in alloy were studied. The results show that the alloy composition can＇t be determined by saturation magnetization value alone, but any nominal mark alloy composition can all be accurately defined by the alloy density value. The microstructure of two-phase WC-Ni alloy can be exactly charactered by use of any two parameters among Cwc （or γ-phase free path λ）.γ-phase volume fraction fy and WC-phase average grain size Lwc. So the independent effect of Cwc on mechanical property can be quantitatively evaluated. The average Vickers hardness of the ＇alloy can be calculated both by use of the＂mixture role＇for every phase＇s ＂in situ＂ hardness and by use of the positive correlation with Cwc or the opposite Hall-Petch type correlation with λ.