Investigation of vertical compensation friction stir-welded 7N01-T4 aluminum alloy

Abstract

Vertical compensation friction stir welding (VCFSW) is successfully applied to weld 7N01-T4 aluminum alloy, and effects of welding speed on joint quality are investigated. The results show that when compensation strip width is 1 mm, the defect-free joint is obtained at the welding speed of 50 mm/min and constant rotational velocity of 2000 rpm. Moreover, the intercalation lamellae structure formed in nugget zone (NZ) can reveal material flow behavior clearly. As strip width increases to 1.5 mm, it is difficult to attain sound joint. Decreasing welding speed is beneficial to surface formation of VCFSW joint. The increase of welding speed decreases tensile strength and elongation of joint. At the welding speed of 50 mm/min and strip width of 1 mm, the tensile strength and elongation of VCFSW joint are 295.7 MPa and 6.7 %, equivalent to 66 and 39.4 % of BM, respectively, while fracture surface of joint presents typical ductile fracture. The hardness distribution of joint shows typical W shape, and the hardness of NZ exhibits uniform distribution.

Friction stir welding industrialisation and research status

“…All the procedures developed to optimise the performance of the FSW technology, in the joining of similar and dissimilar combinations of base materials, were classified as techniques related to the FSW technology (FSW variants). Analysing Table 1, where the FSW variants are listed, it is possible to conclude that the procedures developed aimed the enhancement of the heating conditions during welding [56][57][58][59][60][61], the improvement of base materials stirring/bonding [62][63][64][65][66][67][68][69] and/or the fabrication of double-sided joints [70][71][72]. FSW procedures/tools developed with the specific aim of enabling the joining of dissimilar materials [73][74][75][76], very thin plates [77] or performing weld repair [78] were also identified and classified as FSW variants.…”

“…Friction stir vibration welding (FSVW) [62] In situ rolling friction stir welding (IRFSW) [63] Reverse dual-rotation friction stir welding (RDR-FSW) [64] Self-reacting friction stir welding (SR-FSW) [65] Ultrasonic energy-assisted FSW (UAFSW) [66,67] Vertical compensation friction stir welding (VCFSW) [68] Pulsed friction stir welding (PFSW) [69] Double side welding Asymmetrical double-sided FSW (DFSW) [70] Bobbin friction stir welding (BFSW) [71] Double-sided friction-stir welding (DS-FSW) [72] Promote dissimilar joining Friction stir dovetailing (FSD) [73] Friction stir knead welding [74] Friction stir soldering [75] Friction stir weld assisted diffusion bonding [76] Very thin plates Micro-friction stir welding (µFSW) [77]…”

An investigation of post-weld heat treatment of friction stir welded aluminium blanks AA2024 embedded with AA7075

“…They also deduced that when increasing the width of interlayer material, the peak temperature of welding zone was decreased, which is reduced the atomic diffusion between the CM and BM that is appearing the defect of kissing bonding. Moreover, Ji et al [4] they studied the influence welding speed on the quality of aluminium alloys joints via VCFSW technique. They used 7N01-T4 as BM while AA2024 as CM.…”

Comparison of Al-Zn-Mg Alloy P-MIG Welded Joints Filled with Different Wires

“…Al-Zn-Mg aluminum alloy is an ideal high-strength structural material due to its high specific strength, good hot workability and corrosion resistance. It is widely used in high-speed train body structure and aeronautical industry [1][2][3][4]. The fusion welding of Al-Zn-Mg alloy has a high sensitivity to hot cracking, the choice of appropriate welding wire is the key to avoid hot cracking.…”