Hot deformation behavior and processing map of AZ61/SiC composites

The hot deformation behavior of as-cast AZ61/SiC composites during uniaxial compression test at temperatures ranging from 280 to 440 celcius and a strain rate of 0.001-1 s(-)1 was investigated. There was an increase in the flow stress of the composites with a decrease int the temperature and increase in the strain rate. Processing maps were developed based on the dynamic material model (DMM) at a maximum strain of 1.2. The effects of the incor-poration of silicon carbide (SiC) particles into the base alloy are discussed. The findings show that the incor-poration of SiC particles into the base alloy effectively enhanced its workability in the low temperature domain. The SiC particles promoted the generation and reduced the mobility of dislocations, effectively meeting the energy requirements for dynamic recrystallization (DRX) needed to improve low temperature workability. The optimal processing workability conditions for a AZ61/SiC composite with a higher dissipation efficiency of (PDE) of 39.5% were determined to be 4400C/0.001 s(-1). The instability domain did not exist in the composite because the material could be deformed without micro cracks or flow visualization. The activation energy was calculated to be 131.5 kJ/mol using a constructive model of the composite.