压铸工艺对汽车用镁合金组织与性能影响

Influence of Die Casting Process on Microstructure and Properties of Magnesium Alloy for Automobile

采用不同浇注温度和型腔真空压力进行了AM50Ce汽车镁合金的真空压铸试验,并进行了显微组织和力学性能的测试与分析。结果表明:在650～730℃浇注温度和1～30 kPa型腔真空压力,随浇注温度升高,型腔真空压力减小合金的强度先提高后下降。与650℃浇注相比,型腔真空压力8 KPa690℃浇注时合金抗拉强度增大89MPa(从174到263MPa),平均晶粒尺寸减小16μm(从22到6μm);690℃浇注时,与30 kPa型腔真空压力相比,采用8kPa型腔真空压力时合金抗拉强度增大71MPa(从192到263 MPa),平均晶粒尺寸减小14μm(从20到6μm)。合金的浇注温度和型腔真空压力分别优选为690℃、8 kPa。

The vacuum die casting test of AM50 Ce automobile magnesium alloy was done by using different pouring temperatures and cavity vacuum pressures.The microstructure and mechanical properties were tested and analyzed.The results show that under pouring temperature of 650-730℃ and cavity vacuum pressure of 1-30 kPa,the strength of the alloy firstly increase and then decrease with the increase of pouring temperature or decrease of cavity vacuum pressure.Compared with the pouring temperature of 650℃,the tensile strength of the alloy increases by 89 MPa(form 174 to 263 MPa)and the average grain size decreases by 16 μm(form 22 to 6 μm)when the pouring temperature is 690℃and the cavity vacuum pressure is 8 KPa.Compared with the cavity vacuum pressure of 30 kPa,the tensile strength of the alloy increases by 71 MPa(form 192 to 263 MPa)and the average grain size decreases by 14 μm(form 20 to 6 μm)when the cavity vacuum pressure is 8 kPa and the pouring temperature is 690℃.The pouring temperature and cavity vacuum pressure of the alloy are 690℃ and 8 kPa,respectively.