High-productivity and high-strength Fe/Al dissimilar metal joining by spot forge welding

2020 ◽  
Vol 278 ◽  
pp. 128412 ◽  
Author(s):  
Hideki Yamagishi
Author(s):  
Luke Walker ◽  
Ying Lu ◽  
Colleen Hilla ◽  
Wei Zhang ◽  
Byoung Ou ◽  
...  

Abstract Ultrasonic interlayered resistance spot welding (Ulti-RSW) is a recently developed method for dissimilar metal joining of aluminum alloy to advanced high strength steel. It makes use of a thin insert (or interlayer) which is first ultrasonic spot welded to one of the two sheets. The second sheet is then resistance spot welded to the insert side of the first sheet. In the present study, two inserts were tested, 0.3-mm-thick AA3003-H14 and 0.25-mm-thick stainless steel 316, for joining 0.8-mm-thick Zn-coated (galvannealed) dual phase steel 590 to 1.2-mm-thinck aluminum AA6022-T4. The joint with the aluminum insert achieved a peak tensile-shear strength of 4.1kN and a fracture energy of 1.7J, while the joint with the stainless steel insert achieved a peak strength of 4.5kN and a fracture energy of 2.6J. Both welds were much stronger than a direct resistance spot weld between the two sheets which had a strength of 3.3kN and an inferior fracture energy of 0.87J. The increase in strength and fracture energy achieved using stainless steel insert over aluminum insert was discussed based on the nugget diameter and the interface microstructure.


2020 ◽  
Vol 29 (11) ◽  
pp. 7239-7249
Author(s):  
Changcheng Sang ◽  
Xiaoping Cai ◽  
Lu Zhu ◽  
Xuanru Ren ◽  
Gao Niu ◽  
...  

2006 ◽  
Vol 510-511 ◽  
pp. 362-365 ◽  
Author(s):  
Young Ok Yoon ◽  
Hyung Ho Jo ◽  
Jin Kyu Lee ◽  
Dong In Jang ◽  
Shae K. Kim

Thixoextrusion, one of the thixoforming processes, has advantages of high productivity, reduction of the extrusion pressure, extension of the die life, and cost saving owing to its low energy consumption compared with the conventional extrusion processes. Especially, thixoextrusion process is expected to be very effective for hard-to-form materials with high strength. The present study focuses on 7075 Al wrought alloy to investigate the potential industrial applications of the thixoextrusion process. The microstructural evolution of 7075 Al wrought alloy for thixoextrusion was investigated with respect to isothermal holding temperature and time in the partially remelted semisolid state. The results showed that the liquid fraction increased with increasing isothermal holding temperature and time while the average grain size was inversely proportional to isothermal holding temperature and time up to 5min. However, there was no big change of liquid fraction and average grain size with respect to isothermal holding temperature and time. The important fact that the liquid fraction and average grain size were almost uniform after 5 min holding time is considered very useful for thixoextrusion in terms of process control.


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