Papers by Author: L.W.F. Mackenzie

Abstract: The deformation and recrystallization behavior of two magnesium alloys, AZ31 and WE43, have been investigated. The cast alloys were heat treated to produce various distributions of second phase particles and deformed in a channel die at a strain rate of 10-4 s-1 at temperatures between 523 and 673 K. The alloys were subsequently annealed at temperatures between 708 and 798 K.The AZ31 and WE43 were extruded at 555 and 633 K, respectively. The microstructures were compared to those developed during channel die deformation. The tensile and compressive strengths and the texture of the alloys were determined in the as-extruded and recrystallised conditions.Optical microscopy and electron backscattered diffraction (EBSD) were used to characterize the microstructures of the alloys. The EBSD technique was used to determine the texture of the deformed and annealed samples.

Abstract: The deformation and recrystallization behaviour of two magnesium alloys, WE43 and an experimental “Alloy A1” containing a large amount of second phase, have been investigated. Optical microscopy and electron backscattered diffraction (EBSD) were used to observe each alloy after deformation in a channel die at 553 and 558 K and subsequent recrystallization during annealing at 673 K. Alloy A1 dynamically recrystallised during deformation at 553 and 558 K. In WE43 the particle distribution affected the onset of dynamic recrystallization. Both alloys exhibited evidence of particle stimulated nucleation (PSN) of recrystallization at second phase particles as well as recrystallization at pre-existing grain boundaries. The A1 and WE43 alloys were extruded at temperatures of 573 K and 633 and 663 K, respectively. The extruded microstructures were compared to those that developed during channel die deformation.