WC—Co硬质合金硬度的磁性评估原理

Evaluating Principle for Hardness of WC-Co Alloy by Magnetism

实验结果和理论分析表明 ,基于与合金的显微结构参数和成分的密切对应关系 ,烧结态的两相 WC- Co硬质合金的比矫顽磁力 HSC同γ相平均自由程λγ 和平均硬度 HV间存在确定的对应关系 :HSC=2 .31- 1.5 0 / (1- 192λγ ) ,HV =5 70 4 +2 397/(1- 1.2 3HSC)。根据上述关系式用 HSC测定值能够有效地无损鉴定烧结态两相 WC— Co合金的γ相平均自由程和间接评估平均硬度。导出了一定钴含量 w Co的两相 WC— Co硬质合金的最高抗弯强度σ。TRS所对应的最佳γ相平均自由程λ。γ=3.15× 10 — 7/ (0 .92 0 -w Co)和最佳比矫顽磁力 H。SC=2 .31- 1.5 0 / (1- 0 .10 8/ 0 .892 - w Co)。根据 HSC与 HV和断裂韧性 Kl C及在 λγ 低于 λ。γ 的情况下同 σTRS的定量关系 :Kl C=31.3- 2 7.1HSC,σTRS=4 .5 4× 10 3- 3.93× 10 3HSC,用 H。SC能够有效地间接评估合金的最佳综合力学性能 HV。 、K。l C和 σ。TRS。

The experimental results and the theoretical analysis show that,there are the definite relations of the specific coercive force H SC with the γ-phase mean free path λ γ and the mean Vickers hardness HV of sintered state of two-phase WC-Co cemented carbides:H SC =2 31-1 50/(1-192λ γ),HV=5704+2397/(1-1 23H SC ) owing to the close relation of the H SC ?the HV with the microstructure parameter and the composition in alloy.The λ γ of sintered state of two-phase WC-Co alloy can be effectively and indestructibly examined and the mean Vickers hardness HV can be indirectly evaluated by H SC on the basis of the above-mentioned formulae.The best γ-phase mean free path λ? γ=3 15×10 -7 /(0 920-w Co ) and the best specific coercive force H? SC =2 31-1 50/(1-0 1080 892-w Co ) corresponding to the most transverse rupture strength σ? TRS of correspondent cobalt content-bearing two-phase WC-Co alloy were deduced.The best synthetic mechanical properties i.e. the best mean Vickers hardness H?V?the best fracture toughness K? lc and the σ? TRS can be indirectly evaluated by the H? SC on the basis of the relations of H SC with HV?K lC and the σ TRS when λ γ less than the λ? γ:K lC =31 3-27 1H SC ,σ TRS =4 54×10 3-3 93×10 3H SC .