Die-Cast magnesium alloys have seen an increase in use for automotive components because of their high strength-to-weight ratio, dimensional accuracy, high integration and part consolidation with weight reduction and potential cost competitiveness. In this trend most of the bigger Automotive Industries are going to develop also Mg die-cast parts for body application like door frames, trunk frames, front ends. From here there is the strong request to develop and put into production a surface treatment that could guarantee the resistance of the part in the aggressive atmosphere environment. Among the surface treatment today available or under development anodising and fluorozirconate seem to be good compromises between corrosion and paint adhesion. In order to better evaluate these processes on industrial scale and for large components, TEKSID R&D Tech Center has recently set up a pilot plant for Mg Anodising with ANOMAG process and has tested for comparison the fluorozirconate process. Both processes have been used to treat large castings (seat frames, doors, front ends) on preproduction series. IntroductionDie-Casting magnesium alloys have seen an increase in use for automotive components because of their high strength-to-weight ratio, dimensional accuracy, high integration and part consolidation with weight reduction and potential cost competitiveness. The magnesium alloys have very good casting properties and are particularly suited to diecasting at high production rates making the final component able to assume complex shape integrating functions in one part. This feature is making the material quite attractive for application that can become cost competitive with assembled structure.Some die-casting alloys have such a good fluidity that thin wall casting with minimum of 1.8 mm thickness can be obtained for lighter component.Due to all the above reasons the use of magnesium alloy die castings in automotive applications is steadily increasing in the recent years.Till now the growth of magnesium applications is mainly found in components which are exposed to very mild or non corrosive environments. Examples of such components are steering wheels, steering bracket support, instrument panels, cross car beams and seat frames. As soon as the Mg castings were always in the interior of the car body, there was no great needing in corrosion protection.Magnesium Alloys and their Applications. Edited by K. U. Kainer.

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Nowadays, one of the most crucial focus in the aluminium-foundry sector is the production of high-quality castings. Mainly, High-Pressure Die Casting (HPDC) is broadly adopted, since by this process is possible to realize aluminium castings with thin walls and high specific mechanical properties. On the other hand, this casting process may cause tensile states into the castings, namely residual stresses. Residual stresses may strongly affect the life of the product causing premature failure of the casting. Various methods can assess these tensile states, but the non-destructive X-Ray method is the most commonly adopted. Namely, in this work, the residual stress analysis has been performed through Sinto-Pulstec μ-X360s. Detailed measurements have been done on powertrain components realized in aluminium alloy EN AC 46000 through HPDC processes to understand and prevent dangerous residual stress state into the aluminium castings. Furthermore, a comparison with stresses induced by Rheocasting processes is underway. In fact, it is well known that Semi-Solid metal forming combines the advantages of casting and forging, solving safety and environmental problems and possibly even the residual stress state can be positively affected.

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