effect of pr on microstructure and workability evolution of am50 alloy in extrusion processes

mg alloys have many applications in different industries due to their high strength to weight ratio such as aerospace, automotive and even bio materials. microstructural stability is a crucial but controversial issue for mg-al-re alloys. it is important to study the thermal stability of al-re intermetallic phase with individual re element. this work carried out to investigate the effect of extrusion process on the microstructure of mg-al-mn (am50) alloys by adding 0.5 and 1wt.% pr to this alloys. the presence of stable al-pr phases was also demonstrate in this study .the samples were examined by using optical microscopy (om) to evaluate the modification efficiency of the extrusion and the result show that grain size of alloys decrease with pr element. measuring grain size in extruded and casting mode show that reduction in grain size from 76μm to 10μm from as-cast to extrude condition.