  The through-process microstructural effects in A356 subjected to rotary
forming at elevated temperatures have been investigated. Macro and
micro-hardness testing have been used extensively to track changes in the
material from the as-cast state to as-formed, and T6 heat treated. Targeted
thermal treatments have been used to isolate the effects of mechanical
deformation through comparative measurements. These measurements include macro
and micro hardness measurements, Energy-dispersive X-ray analysis and
examination of eutectic-Si particle size and morphology. The results indicate
that the as-cast material is stable up to approximately 144{\deg}C, with the
rotary formed material exhibiting decreased macrohardness in-line with the time
spent at elevated temperature. Post heat treatment, there was a significant
decrease in hardness with increased levels of deformation. Results indicate
that precipitation hardening is not appreciably affected by rotary forming, and
the principal cause for the drop in hardness with deformation is due to the
condition of Al-Si eutectic phase.
