Characterization of Hot Cracking Due to Welding of High-Strength Aluminum Alloys

Abstract

The ''Spot-Varestraint Test'' was applied to assess the sensitivity of three aluminum alloys-A2024-T351, A2219-T87, and A7050-T6-to hot cracking from welding. The results indicate that the number of cracks increases with increasing augmented strain. This phenomenon occurs in both the fusion and the heat-affected zones. The number of thermal cycles also has a significant influence on the heat-affected zone; the number of hot cracks increases, especially in the heat-affected zone of the metal weld, with increasing number of thermal cycles. The compositions of these three alloys show that A2024 and A7050 have similar tendencies to be subject to hot cracking, greater than A2219. With increasing number of thermal cycles, the hot cracks show the same tendency, A2024 > A7050 > 2219.

Microstructure in hot cracking mechanism of welded aluminium alloys

“…The phenomenon of segregation of elemental Cu is consistent with the results of research for the comparison of sensitivity to hot cracking of various materials. 20 The elemental Cu of A2219 alloy has a segregated status at the grain boundary of PMZ, consistent with the results of Huang and Kou. 24 The experimental results also rendered a large amount of elemental Cu segregating near the grain boundary and increasing with the number of thermal cycles.…”

“…The technical literature reports little investigation of the hot cracking mechanism of high strength aluminium alloys; the previous articles that have been published focus on the characterisation of hot cracking. 20 For the mechanism of hot cracking, the main objective of the present research is the microstructure in the hot cracking mechanism at the welding zone for these high strength aluminium alloys.…”

Evolution of Microstructure and Mechanical Properties in a Single-Stage Aged 7075 Aluminum Alloy Pulse Variable Polarity Plasma Arc Welded Joint

“…Due to their excellent mechanical properties, 7××× series high-strength aluminum alloys are widely used in aerospace, national defense, navigation, automobile, and other fields [1][2][3][4][5][6]. A proper welding method is often needed in practical applications, and achieving high-quality welding has been a hot and challenging research topic [7,8]. Compared to other traditional fusion welding techniques, PVPPAW technology has significant advantages in welding aluminum alloys [9][10][11], such as the small deformation, energy concentration, absence of a need for groove preparation, narrow weld bead, one-sided welding, and both sides formation.…”

Review of Aluminum Alloy Development for Wire Arc Additive Manufacturing

“…Joining of materials by fusion-based methods can imply a range of cracking mechanisms in the as-solidified weld. Hot cracking in the partial melted zone is a common cracking mechanism in arc welding, but it was not reported for WAAM materials [ 73 ]. The most prominent mechanism for aluminum and its alloys in WAAM is solidification cracking, which happens in the liquid melt pool.…”