WC－20Co硬质合金钎焊的热处理机理

Effect of high frequency brazing followed by quenching on microstructure of WC-20Co cemented carbide blade

研究了高频钎焊同时淬火处理对ＷＣ－２０Ｃｏ硬质合金刀片显微结构和性能的影响。结果表明，在１０００～１２００℃温度范围内处理将导致ＷＣ－２０Ｃｏ合金刀片中ＷＣ相邻接度∑ＷＣ－ＷＣ下降、ｒ相平均自由程Ｌ＿ｒ增加、韧性改善和硬度提高等一系列淬火效果。断口形貌微观特征也表明了合金韧性的提高。当处理温度超过１２００℃后，ＷＣ－２０Ｃｏ合金的显微结构和性能将恶化。

The effect of high frequency brazing followed by quenching on the microstructure of WC-20Co hard metal blades has been studied.The result showed that when the operating temperature was between 1000～1200 ℃, a series of quenching effects,such as the WC-phase contiguity ∑ WC-WC decreasing,the r-phase mean free path L_r increasing etc., would take place. These changes are favourable for improving the strength and the toughness and had been in accord with the appearance of fracture. When the operating temperature was above 1200 ℃,the microstructure and the performance of WC-20Co alloy blade would get worse.