模具温度和浇注温度对AZ91D镁合金热裂和流动性能的影响

Effect of Mould Temperature and Pouring Temperature on the Hot Tearing and Fluidity of AZ91D Magnesium Alloy

研究了模具温度和浇注温度对AZ91D镁合金热裂性能与流动性能的影响。结果表明,提高模具温度可以显著改善合金的抗热裂性能;当模具温度为368℃时,AZ91D合金在各种浇注温度下均不产生热裂;当模具温度较低(<268℃)时,浇注温度为688℃时,合金的抗热裂性最佳;随着模具温度提高,浇注温度对合金热裂性的影响逐渐减弱消失。浇注温度与模具温度对AZ91D镁合金的流动性能影响显著,两者的提高均能改善合金的流动性能。当模具温度较低(68℃)时,少量提高模具温度不能显著改善合金的流动性能;当浇注温度较高(718℃)时,进一步提升浇注温度,也不能明显改善合金的流动性能。为了获得较好的流动性能与抗热裂性能,应采用较高的模具温度(≥268℃)和适当的浇注温度(688～718℃)生产AZ91D镁合金产品。

Effects of mould temperature and pouring temperature on hot tearing and fluidity of AZ91D magnesium alloy were investigated.The results indicate that hot tearing resistance of the AZ91D alloy can be significantly improved with the increase of mould temperature.Hot tearing in the AZ91D magnesium alloy can not be observed with preheating temperature of 368℃ at different pouring temperatures.At a lower mould temperature（268 ℃）,AZ91D alloy exhibits the desirable hot tearing resistance with pouring at 688℃.The influence of pouring temperature on hot tearing resistance is fade with the increase of mould temperature to be disappeared at mould temperature of 368 ℃.Both pouring temperature and mould temperature can obviously improve the fluidity of the AZ91D magnesium alloy,showing the remarkably role.At a lower mould temperature（68 ℃）,a little increase of mould temperature can only increase the fluidity slightly,while with pouring temperature at a higher level（718 ℃）,the effects of the increase of the pouring temperature on the improvement of the alloy＇s fluidity can be neglected.In order to get better fluidity and hot tearing resistance,it is suggested for the production of AZ91D magnesium alloy components at a higher mould temperature（≥268 ℃） and suitable pouring temperature（688~ 718 ℃）.