汽车用新型高强镁合金的挤压工艺优化

Extrusion Process Optimization of New High Strength Magnesium Alloyfor Automobile

测试和分析了汽车用Mg-6Al-3Sn-1Mn高强镁合金的性能。结果表明:镁合金的强度随挤压温度和挤压比的增加先增大后减小,而伸长率反之,腐蚀电位随挤压温度和挤压比的增加先正移后负移。380℃挤压温度下的抗拉强度和屈服强度比320℃挤压温度的分别增大了11.26%、15.89%,腐蚀电位正移了51 mV。与挤压比14相比,挤压比22下的抗拉强度和屈服强度分别增大了10.16%、14.81%,腐蚀电位正移了46 mV,耐腐蚀性能先提升后下降。汽车用Mg-6Al-3Sn-1Mn高强镁合金的挤压工艺参数优选为:挤压温度380℃、挤压比22。

The properties of high strength magnesium alloys for automotive Mg-6Al-3Sn-1Mn were tested and analyzed.The results show that the strength of magnesium alloy increases first and then decreases with the increase of extrusion temperature and extrusion ratio,while the elongation is the opposite,the corrosion potential shifts first positive and then negative with the increase of extrusion temperature and extrusion ratio.Compared with those of the extrusion temperature at 320℃,the tensile strength and yield strength of the sample at the extrusion temperature of 380℃increase by 11.26%and 15.89%respectively,and the corrosion potential shifts positively by 51 mV.Compared with those of the extrusion ratio of 14,the tensile strength and yield strength of the sample at extrusion ratio of 22 increase by 10.16%and 14.81%respectively,and the corrosion potential moves positively by 46 mV.The corrosion resistance increases first and then decreases.The optimized extrusion process parameters of Mg-6Al-3Sn-1Mn high strength magnesium alloy for automobile are extrusion temperature of 380℃and extrusion ratio of 22.