差压铸造工艺参数对汽车高强镁合金性能的影响

Effect of Technological Parameters of Differential Pressure Casting on Properties of Automobile High Strength Magnesium Alloy

对差压铸造的汽车用高强镁合金Mg-8.5Al-0.8Zn-0.8Ce-0.5Zr的力学性能和耐腐蚀性能进行了测试和分析。结果表明:随浇注温度、充型压力和充型速度的增加,抗拉强度和屈服强度先增大后减小,断后伸长率先减小后增大,腐蚀电位先正移后负移,耐腐蚀性能先提升后下降。高强镁合金Mg-8.5Al-0.8Zn-0.8Ce-0.5Zr的差压铸造工艺参数优选为:690℃浇注温度、30 kPa充型压力、60 mm/s充型速度。在此工艺下,试样的抗拉强度、屈服强度分别为334、248 MPa,断后伸长率为8.1%,腐蚀电位为-0.834 V。

The mechanical properties and corrosion resistance of Mg-8.5Al-0.8Zn-0.8Ce-0.5Zr high strength magnesium alloy for automobiles were tested and analyzed.The results show that with the increase of pouring temperature,mold-filling pressure and mold-filling speed,the tensile strength and yield strength increase first and then decrease,the elongation after breaking decreases first and then increases,the corrosion potential first shifts positively and then negatively,and corrosion resistance first increases and then decreases.The optimum parameters of differential pressure casting for high strength magnesium alloy Mg-8.5Al-0.8Zn-0.8Ce-0.5Zr are as follows:pouring temperature at 690℃,filling pressure of 30 kPa,filling speed of 60 mm/s.Under this process,the tensile strength and yield strength of the samples are 334 and 248 MPa,elongation after break is 8.1%,and the corrosion potential is-0.834 V.