2 – Welding metallurgy
01 Jan 2002-pp 10-34
About: The article was published on 2002-01-01. It has received 15 citations till now. The article focuses on the topics: Welding.
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TL;DR: In this paper, the authors present an overview of the dissimilar welded joint's microstructure and mechanical behavior, and the effect of intermetallic phases such as sigma phase, FCC carbides like (M23C6, M6C, and M7C3), laves phase, R and χ-phase, Z-phase on the mechanical property of dissimilar welding joints of each material are reviewed in detail.
64 citations
TL;DR: In this paper, electrically vaporized foil actuators (VFA) provided the high-pressure pulses needed for impact welding, which failed in coach-peel outside the joint interface.
Abstract: Joining aluminum alloy sheets is increasingly important in manufacturing. Traditional welding techniques create a heat-affected zone (HAZ) around the joint; however, solidstate joining methods such as impact welding produce joints without significant heat. Here, electrically vaporized foil actuators (VFA) provided the high-pressure pulses needed for impact welding. 0.96 mm thick AA6061-T6 and 0.76 mm thick AA5052 were joined in lap and spotlike configurations, at a variety of impact velocities. The welds failed in coach-peel outside the joint interface. The 5052 hardened within 100 lm of the interface. The 6061-T6 may have softened slightly within 50 lm of the interface. [DOI: 10.1115/1.4030934]
19 citations
12 Apr 2021
TL;DR: In this article, a comparison is presented between Inconel 625 specimens obtained with different laser-powder bed fusion (L-PBF) conditions, and the effects of the energy density (VED) values on as-built and heat-under microstructures are also investigated.
Abstract: The microstructures induced by the laser-powder bed fusion (L-PBF) process have been widely investigated over the last decade, especially on austenitic stainless steels (AISI 316L) and nickel-based superalloys (Inconel 718, Inconel 625). However, the conditions required to initiate recrystallization of L-PBF samples at high temperatures require further investigation, especially regarding the physical origins of substructures (dislocation densities) induced by the L-PBF process. Indeed, the recrystallization widely depends on the specimen substructure, and in the case of the L-PBF process, the substructure is obtained during rapid solidification. In this paper, a comparison is presented between Inconel 625 specimens obtained with different laser-powder bed fusion (L-PBF) conditions. The effects of the energy density (VED) values on as-built and heat-under microstructures are also investigated. It is first shown that L-PBF specimens created with high-energy conditions recrystallize earlier due to a larger density of geometrically necessary dislocations. Moreover, it is shown that lower energy densities offers better tensile properties for as-built specimens. However, an appropriate heat treatment makes it possible to homogenize the tensile properties.
11 citations
TL;DR: In this paper, the microstructural evolution of solidification cracking for an Al-Cu alloy at the weld crater without applying an external force was studied using synchrotron X-ray imaging.
11 citations
TL;DR: In this article, the effects of surface roughness on microstructural and mechanical properties of solid-state diffusion bonding between two dissimilar alloys of magnesium AZ91-D and aluminum 6061 by means of hot pressing were studied.
Abstract: The effects of surface roughness were studied on microstructural and mechanical properties of solid-state diffusion bonding between two dissimilar alloys of magnesium AZ91-D and aluminum 6061 by means of hot pressing. Although applied pressure, temperature, and duration of diffusion bonding are known as the most effective parameters, surface roughness can alter the mechanical and microstructural properties remarkably, which is usually neglected. To investigate the effect of surface roughness between 0.06 and 0.15 μm, the width of the diffusion bond in the interfacial transition zone (ITZ) and the presence of intermetallic phases were analyzed. Moreover, microhardness, shear strength, and fracture surfaces were evaluated. The results exhibit that in the applied roughness range, the bond width and the microhardness of the joints improved by increasing the surface roughness of the both metals; however, the shear strength decreased. It may be attributed to more disruption of the oxide films on the metal surfaces in the rougher samples and also increase in the effective interface boundary during the process. Consequently, there would be more chance for aluminum-magnesium contacts, resulting in more diffusion, further formation of brittle intermetallic phases (such as Al12Mg17 and Al3Mg2), and therefore more hardness and less shear strength.
8 citations