Tensile, microhardness and microstructural characteristics of friction stir welded/processed AA7075 alloy: A review

Abstract

The aircraftand automobile industries have a great demand for aluminium alloys such as AA7075 due to their excellent features. However, it is difficult to join AA7075 using electric arc welding process. Therefore, a novel green welding process namely, friction stir welding (FSW), could be employed for fabricating the joints without any defects. FSW, is a proven solid state joining process capable to join several key engineering materials such as aluminium, magnesium, copper, titanium, and several steel grades. In this review study, the FSW characteristics of a well-known aircraft alloy AA7075 is presented systematically. Weld/processed characteristics such as microhardness, ultimate tensile strength, and microstructural are discussed. It is observed that, FSW process could yield better joints without any defects unlike in traditional welding processes. By proper selection of tool and process parameters will result in improvement of weld efficiency of AA7075 alloy. Fine grained microstructure resulting in better hardness and strength of AA7075 joints. However, there is lack of studies that needs to be carried out on integration of the digital tools such as artificial intelligence (AI) and machine learning (ML) is necessary to reduce FSW time.