钴铬钼合金股骨柄液态模锻的数值模拟

Numerical simulation of melted metal die forging of CoCrMo alloy femoral stem

采用ProCAST软件对钴铬钼合金股骨柄液态模锻过程的温度场、速度场、收缩和气孔缺陷进行了数值模拟,研究了浇注温度、模具温度和液锻速度对铸件充型和凝固过程的影响。结果表明,充型过程中,金属液正面冲击型壁,在股骨柄颈部和头部形成紊流,有卷气的危险。凝固时间的最显著影响因素是模具温度,股骨柄头部顶端存在较大范围的氧化物富集区。可以通过在浇注前向模具型腔中通入惰性气体,在股骨柄前端设置排气槽及在其头部最高位置设置排气塞等措施,得到充型完整、无缩孔缩松的钴铬钼合金股骨柄。

The article researched simulation of the melted metal die forging process of temperature field,velocity field,shrinkage porosity and oxides of femoral stem of CoCrMo alloy and effects of casting temperature,mold temperature and forging speed on the filling and solidification with the help of the software ProCAST.The results indicated molten metal impact ran into the wall of the mold cavity and formed turbulent flow in the neck and head of the femoral stem,which posed risk of gas entrainment.Forging speed has obvious influence on oxides:the higher of forging speed,the lower of oxides contents.The molten alloy ran into the wall of the mold cavity and formed turbulent flow in the neck and head of the femoral stem whose top appeared oxides-rich area.CoCrMo alloy femoral stem whose casting was complete without shrinkage porosity have been gotten by injecting inert gas into the mold cavity before molten alloy pouring and setting the exhaust groove at the front of the femoral stem and exhaust plug at the highest position of the head of femoral stem.