New developments in assessing hot tearing in magnesium alloy castings

High performance magnesium parts produced by permanent mold casting often exhibit hot tear defects. Theoretical prediction of hot tears in magnesium alloys has reached only limited success and further research is necessary to enhance understanding of the fundamental mechanisms associated with the formation of this defect.In this research, numerical modeling of the casting process enabled identification of casting regions susceptible to hot tearing. Limitations of modeling the mechanical behaviour of AZ91D alloy casting during hot tearing were identified. The ex situ residual stresses and strains associated with initiation of hot tearing were measured experimentally using neutron diffraction techniques and enabled validation of the numerical model.