Welding Metallurgy of
01 Jan 1987-
About: The article was published on 1987-01-01 and is currently open access. It has received 991 citations till now. The article focuses on the topics: Welding.
Citations
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TL;DR: In this article, the solidification behavior and microstructure of welding transition zone between low-transformation-temperature deposited metals and high-strength low-alloy steels were investigated.
Abstract: The solidification behaviour and microstructure of welding transition zone between low-transformation-temperature deposited metals and high-strength low-alloy steels were investigated. It was found...
8 citations
01 Feb 2023-Materials Science and Engineering A-structural Materials Properties Microstructure and Processing
TL;DR: In this paper , an as-cast Fe42Mn28Co10Cr15Si5 metastable high entropy alloy was welded for the first time using gas tungsten arc welding, and the weld thermal cycle effect on the microstructure evolution over the welded joint was examined using electron microscopy in combination with electron backscatter diffraction, synchrotron X-ray diffraction analysis, and thermodynamic calculations.
Abstract: Weldability studies on high entropy alloys are still relatively scarce, delaying the deployment of these materials into real-life applications. Thus, there is an urgent need for in-depth studies of the weldability of these novel advanced engineering alloys. In the current work, an as-cast Fe42Mn28Co10Cr15Si5 metastable high entropy alloy was welded for the first time using gas tungsten arc welding. The weld thermal cycle effect on the microstructure evolution over the welded joint was examined using electron microscopy in combination with electron backscatter diffraction, synchrotron X-ray diffraction analysis, and thermodynamic calculations. Furthermore, tensile testing and hardness mapping were correlated with the microstructure evolution. The microstructure evolution across the joint is unveiled, including the origin of the ε-h.c.p. phase at different locations of the material. Different strengthening effects measured throughout the joint are associated with the weld thermal cycle and resulting microstructure. A synergistic effect of smaller grain size of the ε-h.c.p. phase in the fusion zone, overturns the reduced volume fraction of this phase, increasing the local strength of the material. Moreover, the brittle nanosized σ phase was also found to play a critical role in the joints’ premature failure during mechanical testing.
8 citations
TL;DR: In this paper, the effects of incorporating Ti3AlC2 MAX phase into Al7075-T6 alloy by friction stir processing as well as adding Al2O3 nanoparticles to obtain a surface hybrid nanocomposite were investigated.
Abstract: This study investigates the effects of incorporating Ti3AlC2 MAX phase into Al7075-T6 alloy by friction stir processing as well as adding Al2O3 nanoparticles to obtain a surface hybrid nanocomposite. These composites were successfully prepared by friction stir processing with a rotational speed of 1000 rpm and a travel speed of 28 mm/min after 3 passes. Optical, atomic force and scanning electron microscopy as well as microhardness, tensile, and wear tests were utilized to characterize the fabricated surface hybrid nanocomposites. Results showed that the maximum tensile strength and hardness value were achieved for Al-100% Al2O3 composite due to more grain refinement and effective dispersion of nanoparticles. Due to its laminar structure, Ti3AlC2 MAX phase enhanced better tribological characterization, whereas Al2O3 nanoparticles cause better mechanical properties. Scanning electron microscopy tests revealed that the wear mechanism changes from adhesive for Al7075 alloy to adhesive-abrasive for the nanocomposite specimens.
8 citations
TL;DR: In this article, micro-cracks occurred in the weld metal while approaching the process limits of the modified spray arc, represented by a 20mm double layer DV-groove butt-weld.
Abstract: The recent development of high-performance-modified spray arc processes in gas metal arc welding due to modern digital control technology and inverter power sources enables a focused spray arc, which results in higher penetration depths and welding speed. However, microcracks occurred in the weld metal while approaching the process limits of the modified spray arc, represented by a 20-mm double layer DV-groove butt-weld. These cracks were detected in structural steel exhibiting a yield strength level of up to 960 MPa and are neither dependent on the used weld power source nor a consequence of the modified spray arc process itself. The metallographic and fractographic investigations of the rather exceptional fracture surface lead to the classification of the microcracks as hot cracks. The effects of certain welding parameters on the crack probability are clarified using a statistical design of experiment. However, these microcracks do not impact the design specification for toughness in the Charpy V-notch test (absorbed energy at −40 °C for the present material is 30 J).
8 citations
Cites background from "Welding Metallurgy of"
...chemical composition of base and filler metal [7]....
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References
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TL;DR: In this article, the state of the art in selective laser sintering/melting (SLS/SLM) processing of aluminium powders is reviewed from different perspectives, including powder metallurgy (P/M), pulsed electric current (PECS), and laser welding of aluminium alloys.
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TL;DR: In this article, the authors show that the pre-existing dislocation network, which maintains its configuration during the entire plastic deformation, is an ideal modulator that is able to slow down but not entirely block the dislocation motion.
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TL;DR: In this article, the fundamental understanding of structure-properties relationship in automotive steels resistance spot welds is discussed. And a brief review of friction stir spot welding, as an alternative to RSW, is also included.
Abstract: Spot welding, particularly resistance spot welding (RSW), is a critical joining process in automotive industry. The development of advanced high strength steels for applications in automotive industry is accompanied with a challenge to better understand the physical and mechanical metallurgy of these materials during RSW. The present paper critically reviews the fundamental understanding of structure–properties relationship in automotive steels resistance spot welds. The focus is on the metallurgical characteristics, hardness–microstructure correlation, interfacial to pullout failure mode transition and mechanical performance of steel resistance spot welds under quasi-static, fatigue and impact loading conditions. A brief review of friction stir spot welding, as an alternative to RSW, is also included.
369 citations
TL;DR: In this article, a unified equation to compute the energy density is proposed to compare works performed with distinct equipment and experimental conditions, covering the major process parameters: power, travel speed, heat source dimension, hatch distance, deposited layer thickness and material grain size.
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TL;DR: This study attempted to predict solidification defects by DNN regression with a small dataset that contains 487 data points and found that a pre-trained and fine-tuned DNN shows better generalization performance over shallow neural network, support vector machine, and DNN trained by conventional methods.
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