(西安理工大学 材料科学与工程学院，西安 710048)
摘 要: 以Lanxide材料的成形工艺控制为目标，研究了SiO2表面覆盖剂在铝合金熔体直接氧化生长过程中的作用。结果表明有效促进Al2O3/Al复合材料生长的SiO2加入量为1～6 g/dm2。SiO2能够显著促使材料近平面生长，形成细化胞状晶团和提高组织均匀度；在覆盖SiO2的条件下，温度升高，生长速度加快的同时，材料宏观生长表面趋于平整，但温度过高会对组织致密度产生不利影响。
关键字: 直接金属氧化; Al2O3/Al复合材料; SiO2表面覆盖剂; 生长形貌; 微观组织
directed oxidation of molten aluminium alloy
（School of Materials Science and Engineering,
Xi′an University of Science and Technology,Xi′an 710048, P.R.China）
Abstract:With the purpose of controlling Lanxide composite forming technique, the effect of SiO2 as a surface dopant on directed oxidation of molten aluminium alloy was studied. The results show that the optimum content of SiO2 is 1～6 g/dm2, which promotes the near-planar surface, the homogenity of microstructure and fine cellular of Al2O3/Al composites. The higher the growth temperature, the faster the oxidation growth, and the smoother the macro-surface of composite；but the density of composite is lowered down when the temperature is excessively high.
Key words: directed metal oxidation; Al2O3/Al composite； SiO2 surface dopant; growth morphology; microstructure
