WC-Co硬质合金的显微结构参数  

Microstructure Parameters of WC-Co Cemented Carbide

作　　者：刘寿荣[1] 

机构地区：[1]天津硬质合金研究所,天津300222

出　　处：《材料热处理学报》2005年第1期62-64,共3页Transactions of Materials and Heat Treatment

摘　　要：通过X射线衍射分析 (XRD) ,扫描电镜 (SEM)体视学测量和磁性与密度测试 ,并依据碳化钨(WC)基合金维氏硬度HV与γ相平均自由程λ间的Hall Petch型关系式和HV的“混合物规则”进行验证 ,探讨了两相WC Co硬质合金显微结构参数间的定量关系。结果表明 ,γ相平均自由程λ与WC晶粒邻接度CWC 间存在反向对应关系 ,与γ相体积分数fγ 和WC平均晶粒尺寸LWC 间存在正向对应关系 :λ =1 0 5× 10 - 5·(1-CWC) 3 7=8 74× 10 - 2 ·(f- 1γ - 1) - 0 79·L0 79WC ,说明fγ 和LWC对λ～CWC关系的影响处在测量误差范围内 ,因而用CWC(或λ)、fγ 和LWC中任意两个参数都能准确表征两相WC Co硬质合金的结构特征 ;合金的比矫顽磁力HSC与γ相平均自由程λ间存在定量关系 :HSC=4 0 5× 10 - 7 λ。讨论了用磁性和密度测定值无损鉴定两相WC Co硬质合金显微结构参数的可行性。The quantitative relationships between microstructure parameters are deduced by means of XRD phase analysis, SEM stereological technique, magnetism and density testing and are verified by use of the Hall-Petch relation of Vickers hardness with the γ-phase free path λ and the mixture rule of hardness for two-phase WC-base cemented carbide. The results show that the relation of the γ-phase free path λ with the WC grain contiguity is in opposite correlation and the relation of λ with the γ-phase volume fraction fλ and the WC average grain size LWC is in positive correlation: λ = 1.05 × 10-5 (1 -CWC)3.7 = 8.74 × 10-2 (fr-1 - 1)-0.79&middotLWC0.79. It shows that the effect of fλ and LWC on the λ - (1 - CWC) relation is within the limits of test error, so the structure of two-phase WC-Co alloy can be exactly charactered by use of any two parameters among λ (or CWC), fλ and LWC. The relationship of λ with the specific coercive force HSC is HSC = 4.05 × 10-7/λ. The feasibility of predicting the microstructure parameters of two-phase WC-Co alloy by specific coercive force HSC and specific saturation magnetization, density values is discussed.

关 键 词：WC-CO硬质合金 显微结构参数 比矫顽磁力HSC 

分 类 号：TB303[一般工业技术—材料科学与工程] TF125.3[冶金工程—粉末冶金]