MECHANICAL CHARACTERISTICS OF CAST AC7AV ALLOY AFTER ALTERNATIVE MULTI-PASS FRICTION STIR PROCESSING

Friction stir processing (FSP) was used to improve the mechanical characteristics and microstructure of AC7AV cast Al–Mg alloy. The mechanical characteristics of AC7AV deteriorated due to significant defects caused by excessive friction heat after being subjected to multi-pass FSP. An alternative method of multi-pass FSP with two traveling directions was used to solve the defect problems in multi-pass FSP for cast AC7AV Al alloy. The results of various multi-pass FSP experiments showed that the mechanical properties of the cast AC7AV Al alloy specimens subjected to this alternative multi-pass FSP were better than those produced by the conventional multi-pass FSP method.