Sr、B对AZ91镁合金凝固区间和流动性能的影响

Effects of Strontium and Boron Additions on Solidification Temperature Range and Fluidity of AZ91 Magnesium Alloy

以AZ91镁合金为研究对象,利用DSC、流动性试验等分析手段研究Sr、B对AZ91合金凝固区间和流动性能的影响。结果表明:Sr的加入对合金的固相线影响不大,但能明显降低合金的液相线,从AZ91合金的596℃下降到添加0.8%Sr后的566℃,下降了30℃;凝固区间从AZ91合金的161℃下降到添加0.8%Sr后的129℃,结晶温度间隔减小了约20%。在AZ91-0.5Sr合金中添加微量B后,合金的固相线和液相线变化都不大。AZ91合金的流动性浇注试样长度为330mm,AZ91-0.5Sr合金的流动性浇注试样长度为380mm,而AZ91-0.5Sr-0.09B合金的流动性浇注试样长度为580mm,比AZ91合金提高了76%。

Effects of Sr and B additions on the solidification temperature range and fluidity of AZ91 magnesium alloy have been studied by means of DSC and the fluidity test. The results indicated that the liquids temperature of AZ91 alloy decreased markedly with the addition of Sr, but the solidus temperature almost unchanged. The liquids temperature fell from 596 ℃ to 566 ℃ after adding 0.8% Sr, and the solidification range decreased from 161 ℃ to 129 ℃, which decreased about 20%. The liquids and solidus temperature of AZ91-0.5Sr alloy with B addition have no obvious change. The length of fluidity sample of AZ91 was 330 mm, and of AZ91-0.5Sr was 380 mm, while the length of fluidity sample of AZ91-0.5Sr-0.09B was 580 mm, which has increased by 76% compared with that of AZ91.