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Semi-solid metal forming processes are of large industrial interest for the production of various components. Reduction of macro-segregation, reduction of porosity, possibility of near net shape are the principal advantages over casting, forging and powder metallurgy techniques. This paper gives a brief description of the Thixomag® process applied to a AZ91D magnesium alloy. As it is well known, special material properties are required for the thixoforming process. It is especially necessary to homogenize the temperature along the billet during the induction reheating. This homogenization of temperature enables to avoid the coarsening of the primary solid phase and defects in the final part. To determine the optimum conditions and to reduce the process duration, numerical simulation has been used. A 2D model, where thermal and electromagnetic are coupled, was built.

The forming of alloys from the liquid state can be realized thanks to various casting technologies where the temperature of the metal is high enough to fill a given die correctly. A variety of casting defects often occur in the final part, such as gas porosity, shrinkage porosity and hot cracking. In the case of the magnesium foundry, all handling of molten metal requires serious safety precautions to avoid explosion and burning. Protective gas mixtures (SF6, SO2, CO2) are used to minimize the ignition risks but have a bad impact on the environment. The semi-solid forming operates using a lower temperature in the solidus-liquidus range and seems to be interesting, in particular, for the quality requests of the die caster and for safety and a clean environment. The purpose of this paper is to present the mechanical results of tensile tests carried out on magnesium standard samples, which are cast by Thixomag® process from the semi-solid state.

Nowadays the use of magnesium automotive engineering has become an essential way for weight reduction. The change from conventional materials, such as zinc alloys, to lighter weight materials, such as magnesium alloys, is realizable at commercially competitive rates. This requires lightweight solutions, optimized design and advanced manufacturing processes. The goal of this study is to validate the thixocasting process for a part of a wiper system. This paper summarizes the first mechanical tests carried out on a wiper part in AZ91 magnesium alloy by thixocasting and traditional casting process. The semi-solid die casting process enables to improve the mechanical behavior. To explain these results, the effects of microstructure on thermal properties are investigated and microstructural examination is also performed using optical microscope and scanning electronic microscope (SEM).