摘要
本文对含稀土铸造共晶铝合金(ZL108)激光重熔组织进行了变时及变温时效处理,与固溶加时效样品相比,激光重熔组织的显微硬度峰值,在HV—H曲线上后移两小时,在HV—T曲线上后移20℃。激光重熔组织比固溶加时效组织具有较好的耐磨性。该两种工艺样品的磨损量随时效时间及时效温度的变化规律与显微硬度随时效时间及时效温度的变化规律完全一致。激光重熔组织细且耐时效,铝枝晶沿 <100> 晶向生长,θ′相沿{100}晶面析出,该θ′相可使显微硬度和耐磨性得到提高。
Microstructure and properties of the eutectic aluminium silicon alloy (ZL 108) containing RE after ageing with varying time and temperature, have been studied. The microhardness peak of the alloy treated by laser processing lage two hours on the HV-H curve and 20℃ on the HV-T curve compared with that of the alloy treated only by solid solution and ageing. The laser-melted structure has more wear resistance than that treated by solid solution and ageing. The varying of the amount of wearing with the ageing time and temperature is the same as the change of microhardness with the ageing time and temperature. The laser-melted structure is both fine and resistant to ageing, The aluminium dendrites grow along [100] orieutation, and θ phase precipitates on the {100}. This kind of phase increses microahrdness and wear resistance.
关键词
铸造
铝合金
激光
热处理
激光重熔
laser processing
ageing, precipitation
wear resistance.
