原位制备表面增强复合材料的一种新方法

提出了一种利用工频电流制备表面增强复合材料的新方法，其特点是：对合金熔体施加一个交流电，利用交流电及其感生磁场产生的电磁力，迫使电导率较低的第二相向边缘迁移，凝固后得到表面增强的复合材料．利用该方法原位制备了表面硅增强的铝硅合金，表层硬度比单纯的铝基提高10-20倍．该方法工艺简单，不受铸件形状和尺寸的限制，可用于表面增强金属材料的规模化制备．

A novel strategy to fabricate in-situ surface reinforced metal composite

A novel strategy to fabricate surface reinforced metal composites by using an alternating current was reported. The basic principle is that an alternating current is imposed on a molten alloy, the resultant electromagnetic force induces the migration of low-conductivity phase towards the mould wall, thus a in-situ surface composite would be obtained after the solidification of alloy. The method was successfully applied to fabricate the Al-Si alloy reinforced by Si at surface, whose Vickers hardness was increased up to 10-20 times than that of aluminum matrix. Owing to the simplicity in process and the applicability for various shape-and size-casts, the technique allows the mass fabrication of metal-based surface composites.