Microstructure and mechanical properties of 2195/5A06 dissimilar joints made by resistance spot welding

Microstructure and Mechanical Properties of Similar/Dissimilar Resistance Spot‐Welded Aluminum Alloys for Aerospace Applications

“…The microstructure of traditional Al alloys spot welded joint is composed of columnar grains at the edges and equiaxed grains at the center, [ 26–28 ] mainly due to the temperature gradient G and solidification rate R . [ 24,29 ] The smaller the G/R ratio, the greater the supercooling. As the G/R ratio decreases, the sequence of weld solidification morphology is cellular crystal → cellular dendrite → columnar dendrite → equiaxed dendrite.…”

“…As the G/R ratio decreases, the sequence of weld solidification morphology is cellular crystal → cellular dendrite → columnar dendrite → equiaxed dendrite. [ 24 ] In the RSW of aluminum alloy, G/R ratio decreases gradually from the edge to the center of the nugget, which results in the formation of columnar grains at the boundary of the nugget and equiaxed grains at the center of the nugget. The heterogeneous nucleation of Zr and Li elements contributes to the equiaxed grains in the three types of joint.…”

“…Compared with traditional Al alloys like 5052, 5083, and 6061, the microstructure of the FZ is significantly different. The microstructure of traditional Al alloys spot welded joint is composed of columnar grains at the edges and equiaxed grains at the center, [26][27][28] mainly due to the temperature gradient G and solidification rate R. [24,29] The smaller the G/R ratio, the greater the supercooling. As the G/R ratio decreases, the sequence of weld solidification morphology is cellular crystal !…”

“…The heterogeneous nucleation of Zr and Li elements contributes to the equiaxed grains in the three types of joint. [24] Figure 4 shows the SEM and EDS analysis results in the FZ of different RSWed joints. Segregation at grain boundaries and precipitation in grains are common in spot welding of aluminum alloy.…”

A Review on the Friction Stir Brazing for Joining Dissimilar Materials

“…Moreover, these wide applications are increasing with the development of technologies [1]. Joining processes such as brazing [2,3], soldering [4,5], arc welding [6,7], laser welding [8,9], hybrid welding [10,11], electron beam welding [12,13], resistance welding [14,15], ultrasonic welding [16,17], friction crush welding [18,19] and other types of welding processes have been covered in literature. Arc welding processes among all these processes appear as not recommended processes for obtaining felicitous dissimilar welds such as Al-steel based on features of the arc-induced melting and hardening process such as the evolution of brittle intermetallic compounds (IMCs) [20].…”