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介绍了SiC颗粒增强铸造铝基复合材料的铸锭重熔、除气和铸造过程的特征。由于颗粒的存在 ,这些工艺过程和普通铝合金有一定的差异。在铸锭重熔时 ,需要控制熔炼温度和对熔体施加搅拌 ,以防止颗粒反应和下沉。普通铝合金采用的熔盐和气体除气工艺不适合于复合熔体的除气精炼 ,而真空除气具有很好的效果。复合熔体具有高的粘度 ,流动性较差 ,在大气自由重力浇注时容易卷入气体而导致铸件气孔缺陷。为了防止铸件缺陷的形成 ,复合材料在大气自由重力浇注下的浇注系统需要设计集气、集渣冒口和阻流口等特殊组元。真空差压浇注工艺大大简化了浇注系统 ,降低了材料消耗 ,同时消除了大气自由重力浇注时容易产生的铸造缺陷。通过该工艺可获得形状复杂、表面光洁、尺寸精确的铝基复合材料精密铸件
The characteristics of ingot remelting, outgassing and casting process of SiC particle reinforced cast aluminum matrix composites are introduced. Due to the presence of particles, these processes and ordinary aluminum have some differences. In remelting the ingot, it is necessary to control the smelting temperature and to apply agitation to the melt to prevent the particles from reacting and sinking. Ordinary aluminum alloy molten salt and gas degassing process is not suitable for composite melt degassing refining, and vacuum degassing has a very good effect. Composite melt with high viscosity, poor fluidity, free gravity in the atmosphere easy to pour gas into the casting porosity defects. In order to prevent the formation of casting defects, the gating system of composite material under free-air gravity pouring in the atmosphere needs to design special components such as gas gathering, slag riser and choke orifice. Vacuum differential pressure casting process greatly simplifies the casting system, reducing material consumption, while eliminating the free-gravity gravity casting prone casting defects. Through the process can be complex shape, smooth surface, the precise size of aluminum-based composite precision castings