自生长Al_2O_3—Al复合材料的制造及形成机理研究

THE MANUFACTURE OF SELFGROWING A1_2O_3 -Al COMPOSITE AND ITS FORMING MECHANISM

熔融态铝合金表面的Al_2O_3膜在一定工艺条件下可被破坏,由于毛细管作用,内部的金属液将沿着膜上的破缺处上升至表面并产生新的非致密氧化膜。该过程具有自组织特征,一定时间后可在液态合金表面形成一定厚度的自生长Al_2O_3-Al复合材料。材料中Al_2O_3含量可在20％-80％的范围内变化而其性能,尤其是硬度和抗拉强度可有较大提高。

The A12O3 layer on moten aluminium alloys can be damaged in some technological conditions. By capillarity the molten metal will rise to the surface through the broken place on the loyer and form a new A12O3 layer which is not compact and can be passed by molten metal too. This is a self-organic process by which a self growing A12O3-A1 composite with some thickness will be formed on the surface of the molten metal. The proportion of A12O3 in the material can be controlled from 20%-80% while the qualities especially the hardness and tensile strength, are all higher than thoses of the powder metallurgy materials.