Manufacturing of thioxtropic material from etial 160 alloy by cooling slope casting process under vibration and the investigation of its characteristics

Thixoforming is an attractive process for the manufacture of complex parts with substantial savings of time and cost. Different from the conventional metal forming technologies which use either solid metals (forging) or liquid metals (casting) as starting materials, thixoforming deals with semi-solid slurries Thixoforming is composed of three main processes, i.e. thixotropic feedstock production, reheating, and thixoforming. In this study, three steps of the thixoforming process were carried out for A380 alloy. The production of a fine, equiaxed, rosette microstructure (often referred to as ?thixotropic) is a must for the success of the thixoforming process. In the first step, cooling slope (CS) casting process was carried out to obtain such a feedstock. The casting process was realized from both a constant inclined plate and a inclined plate under vibration. Moreover, the production was also carried out gravity casting, at the same time, the constant mold employed gravity casting was exposed to vibration frequency. The effect of casting temperature and vibration on the formation of thixotropic microstructure were investigated. In the reheating step, as-cast billets were partially remelted at semi-solid temperature intervals and isothermally held for suitable durations with an induction furnace in order to observe the microstructural evolution, hardness and grain analysis. In the forming step of the process, as-cast billets were inductively reheated to the temperatures practiced in the second step and then thixoformed between dies. External appearances and capability of the filling mold of the thixoformed samples were investigated. In order to use the advantage of low viscosity presented in the thixotropic feedstocks, thixoforming was performed with lower press loads comparing to the loads and lower press speed used in literature.