Correlating Tensile Properties with Microstructures of Various Regions in Gas Tungsten Arc Welded AA2014 Alloy

AA2014 is a heat treatable aluminium alloy found its application in light weight structures owing to its superior strength to weight ratio. The alloy was welded with automatic gas tungsten arc welding. The microstructure and mechanical properties of each zone such as parent metal (PM), heat affected zone (HAZ) and fusion zone (FZ) of the weldment were studied using optical microscopy, microhardness survey and micro-tensile testing. The PM with elongated grains with evenly distributed Al2Cu phases showed a tensile strength of 456 MPa and 24% elongation; the HAZ and FZ offered a reduction in strength and ductility. The grain coarsening with segregation of continuous string of Al2Cu along grain boundaries in HAZ and the formation of coarse dendritic grains with continuous network of brittle Al2Cu and a minor fraction of porosity at interdendrite in FZ were attribured to the observed strength reduction in these regions. Keywords: AA2014 alloy; gas tungsten arc welding; optical microscopy; microhardness; micro-tensile testing.

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The Role of Welding Parameters on Achieving a Combination of High Strength and Ductility in Gas Tungsten Arc Welding of Cu–7Al–3Fe Aluminum Bronze

The Physics of Metals and Metallography ◽

10.1134/s0031918x18050022 ◽

2018 ◽

Vol 119 (5) ◽

pp. 497-503

Author(s):

Morteza Abbasi ◽

Reza Derakhshandeh-Haghighi

Keyword(s):

Arc Welding ◽

High Strength ◽

Gas Tungsten Arc Welding ◽

Welding Parameters ◽

Aluminum Bronze ◽

Gas Tungsten Arc ◽

Gas Tungsten ◽

Strength And Ductility

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Arc Characteristics and Weld Bead Microstructure of Ti-6Al-4V Titanium Alloy in Ultra-high Frequency Pulse Gas Tungsten Arc Welding (UHFP-GTAW) Process

Materials Science ◽

10.5755/j01.ms.26.4.22329 ◽

2020 ◽

Vol 26 (4) ◽

pp. 426-431

Author(s):

Wei LI ◽

Gaochong LV ◽

Qiang WANG ◽

Songtao HUANG

Keyword(s):

Titanium Alloy ◽

Fusion Zone ◽

Arc Welding ◽

Gas Tungsten Arc Welding ◽

Weld Bead ◽

Gas Tungsten Arc ◽

Arc Characteristics ◽

Arc Pressure ◽

Gtaw Process ◽

Gas Tungsten

To resolve the problem of grain coarsening occurring in the fusion zone and the heat-affected zone during conventional gas tungsten arc welding(C-GTAW) welded titanium alloy, which severely restricts the improvement of weld mechanical properties, welding experiments on Ti-6Al-4V titanium alloy by adopting ultra-high frequency pulse gas tungsten arc welding (UHFP-GTAW) technique were carried out to study arc characteristics and weld bead microstructure. Combined with image processing technique, arc shapes during welding process were observed by high-speed camera. Meanwhile the average arc pressure under various welding parameters were obtained by adopting pressure measuring equipment with high-precision. In addition, the metallographic samples of the weld cross section were prepared for observing weld bead geometry and microstructure of the fusion zone. The experimental results show that, compared with C-GTAW, UHFP-GTAW process provides larger arc energy density and higher proportion of arc core region to the whole arc area. Moreover, UHFP-GTAW process has the obviously effect on grain refinement, which can decrease the grain size of the fusion zone. The results also revealed that a significant increase of arc pressure while increasing pulse frequency of UHFP-GTAW, which could improve the depth-to-width ratio of weld beads.

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