Effect of Process Parameters on Friction Stir Welded Joints between Dissimilar Aluminum Alloys: A Review

Abstract

Friction Stir Welding is a suitable solid-state joining technology to connect dissimilar materials. To produce an effective joint, a phase of optimization is required which leads to the definition of process parameters such as pin geometry, tool rotational speed, rotation direction, welding speed, thickness of the sheets or tool tilt angle. The aim of this review is to present a complete and detailed frame of the main process parameters and their effect on the final performance of a friction stir welded joint in terms of mechanical properties and microstructure. Attention was focused in particular on the connection between different aluminum alloys. Moreover, the experimental results were correlated to the development and the applications of tools which can be effectively used in the design of the manufacturing process such as finite element analyses, artificial neural networks, and statistical studies. The review also aims to be a point of reference to identify the best combinations of process parameters based on the dissimilar aluminum to be joined.

Enhancing the tribological properties of pure Ti by pinless friction surface stirring

“…Therefore, FSS using non-optimised parameters not only changes the surface applied strains but also may change the heat input distribution in the SZ in such a way that worsens the material plastic behaviour. According to Figure 7, probably due to the insufficient heat input (low tool interface temperature) and in agreement with the previous studies [39,40], FSS under the lower-than-optimum rotation speeds or higher-than-optimum traverse speeds may cause defects such as pores, cracks, and kissing bonds in the SZ microstructure (Figure 7(a, b)). Due to the lack of material plasticity and/or inefficient mechanical intermixing of the base plates, the formation of these defects with adverse effects on the hardness of the processed zone (Figure 2) is likely.…”

Studies on the Quality of Joints and Phenomena Therein for Welded Automotive Components Made of Aluminum Alloy—A Review

“…However, Di Bella et al [257] pointed out that the joint quality obtained in the FSW process depends on not only the process parameters but also the features of the Al alloys involved, including their heat treatment and the thickness of the welded sheets.…”

“…Heat-treatable Al alloys from the 2xxx, 6xxx, and 7xxx series obtain their strength from a precipitation hardening process [257]. The high temperatures generated during FSW to various extents dissolve the strengthening precipitates (Cu, Mg, and Zn) in the HAZ of heattreatable alloys.…”

“…Non-heat-treatable Al alloys from the 1xxx, 3xxx, and 5xxx series are insensitive to precipitation hardening [257]. They gain strength via cold working or strain hardening.…”

Study on the Properties of a 2219 Aluminum Alloy Friction Stir-Welded Joint under the Biaxial Stress State

“…The friction stir welding (FSW) technique has been considered ideal for large aluminum alloy structures like propellant tanks [1]. It is a solid-state welding technology and provides direct metal-to-metal contact without the production of intermetallic compounds [2]. FSW structures are easier to achieve a light structural weight with and can provide better structural sealing.…”