【摘要】 在MgO系铸钛包埋料中加入α-Al2O3细粉,经1100℃热处理后,MgO和α-Al2O3可原位生成镁铝尖晶石,导致试样体积膨胀,显气孔率明显增加,耐压强度明显降低。当加入的α-Al2O3细粉为10%、20%(质量分数)时,α-Al2O3细粉几乎全部与MgO反应生成镁铝尖晶石,试样体积膨胀最明显,热膨胀率最大,可以很好地弥补钛铸件的冷却收缩。更多还原

【Abstract】 The magnesium aluminate spinel is formed at 1100℃ with addition of α-Al2O3 fine powder in MgO-based investment materials and the expansion of investments increases,so apparent porosity of the specimen heated at 1100℃ is more than that of the specimen heated at 900℃ and 110℃ slightly,and the compression strength of the spe-cimen heated at 1100℃ is less than that of the specimen heated at 900℃ and 110℃ slightly.When the content of α-Al2O3 fine powder is 10%and 20%,the formation of magnesium aluminate spinel is the most,and the thermal expansion of the specimen is the biggest.So this thermal expansion can make for the shrinkage of Ti castings at low temperature.更多还原