硬质合金氢气烧结麻面的形成机理研究

研究了硬质合金烧结麻面的形成机理。研究结果表明 ,硬质合金烧结麻面形成的根本原因是由于工艺控制不当 ,在产品内、外部形成碳浓度差 ,导致产品的内、外部的共晶温度不同 ,内部碳浓度高于外部碳浓度时 ,内部将优先生成液相 ,生成的液相在毛细管力作用下移向表面 ,并在表面凝固时就形成了产品表面麻面。在烧结中必须注意消除产品内、外部的碳浓度差 ,才可以避免产品烧结麻面

STUDY OF FORMATION MECHANISM OF SINTERING CEMENTED CARBI DE POCK MARKS

Formation mechanism of sintering cemented carbide pockmarks is studied.The result shows that the formed sintering cemented carbied pockmarks is attributed to improper process control.Carbon differential concentration formed in product internal and external leads to different eutectic temperature in products.When internal carbon concentration is higher than external's,liquid phase will produce preferentially in internal.The produced liquid phase shifts to the surface under the capillary action and forms pockmarks as surface solidifies.During sintering it must be noted to eliminate carbon differential concentration in product internal and external to avoid sintering product pockmarks.