Mechanical properties of the pressure die cast magnesium alloy AZ91.

Mechanical properties of the pressure die cast magnesium alloy AZ91. Test automotive components of different wall thickness were investigated with regard to the microstructure property correlation. The assessment of the mechanical behaviour of material was carried out by means of tensile tests, in-situ tensile tests, in-situ bending tests in SEM and microhardness measurements. The results showed that the strength and deformation behaviour of the material is influenced by the microstructure formation and impaired by cast-induced defects. Contrary to the expectations, a very inhomogeneous microstructure was formed in regions with small wall thickness. This microstructure with additionally numerous inner defects did not meet the strength and deformation demands under tensile loading. To obtain acceptable mechanical values, a cast technology and process control precisely adapted to the special component is required.