The influence of melt treatment process on the quality and permormance [i. é performance] of Al based components

Abstract

The performance of a mechanical component is often limited by the intrinsic characteristics of the materials used or by weaknesses/limitations inherent to the manufacturing process. Despite their widespread use, the casting of aluminum alloys is not easy since they are prone to coarse and heterogeneous structures, usually dendritic. Moreover they are susceptible to hydrogen absorption during melting, requiring a set of processing operations of the liquid metal in order to reduce and control the level of porosity and microstructure after solidification. In the context of the application of aluminum alloys, porosity and mechanical properties are a critical factors to the performance of the components. Thus, it becomes important to develop techniques/equipment for treatment of liquid melt leading to high sanity and microstructural characteristics that ensure the best possible mechanical performance, without environmental impact, more efficient and easier to control than those existing today. Ultrasonic vibration treatment (UST) combined with melt agitation promoted by a suitable design can be a reliable, efficient, fast and environmentally friend melt treatment technique. The experimental results suggest that such technique can increase the aluminum alloy theoretical density and mechanical properties without increasing the processing time.