Weld Joint of Tantalum Sheet by Tungsten Inert Gas Welding

2021 ◽  
Vol 1035 ◽  
pp. 739-745
Author(s):  
Yan Fei Chen ◽  
Jin Xiang Zhang ◽  
Zheng Qiang Zhu
Keyword(s):  
Welded Joint ◽  
High Reliability ◽  
Weld Zone ◽  
Argon Atmosphere ◽  
Inert Gas ◽  
Welding Quality ◽  
Tungsten Inert Gas Welding ◽  
High Quality ◽  
Oxidation Degree ◽  
Original Size

The 0.6 mm tantalum sheet was welded under argon atmosphere by Tungsten Inert Gas Welding (TIG) in order to obtain a welded joint with high-quality and high-reliability. Metalloscope, scanning electron microscopy (SEM), and energy dispersive spectroscopy (EDS) were applied to analyze the joint. The results showed that the grain size of the base metal which affected by the welding heat remained the original size or enlarged slightly to 40-70 μm. What’s more, the weld zone was found to be composed of two components with different oxidation degree. And the distribution of these two components was related to the protection atmosphere of the location. The fusion line of the two tantalum sheets was clear which means high welding quality.

scholarly journals Fabrication and Mechanical Properties of Tungsten Inert Gas Welding Ring Welded Joint of 7A05-T6/5A06-O Dissimilar Aluminum Alloy

Materials ◽  
2018 ◽  
Vol 11 (7) ◽  
pp. 1156 ◽  
Author(s):  
Wukun Wang ◽  
Zengqiang Cao ◽  
Kai Liu ◽  
Xianglong Zhang ◽  
Kewen Zhou ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Aluminum Alloy ◽  
Welded Joint ◽  
Inert Gas ◽  
Tungsten Inert Gas Welding

scholarly journals Evaluation of Stainless Steel AISI 316Ti Corner Joints Quality Produced by Tungsten Inert Gas Welding

TEM Journal ◽  
2020 ◽  
pp. 1475-1479
Author(s):  
Dominika Botkova ◽  
Frantisek Botko ◽  
Zuzana Mitalova ◽  
Vladimir Simkulet ◽  
Maros Somsak
Keyword(s):  
Stainless Steel ◽  
Welded Joint ◽  
Welding Current ◽  
Inert Gas ◽  
Optimal Conditions ◽  
Tungsten Inert Gas Welding ◽  
Additional Material ◽  
Steel Aisi ◽  
Stainless Steel Aisi

Welding is one of the most common ways of creating permanent joints in various industries. It is important to constantly look for ways to increase the quality of welds and look for optimal conditions to achieve a quality joint. The presented article is focused on the evaluation of the quality of weldments made of AISI 316Ti material created by TIG technology with additional material and without additional material. The parameter that changed was the welding current. HV hardness measurements and macroscopic weld evaluation were used to evaluate the quality of the welded joint.

Influence of filler material on the microstructure, mechanical properties, and residual stresses in tungsten inert gas welded Ti-5Al-2.5Sn alloy joints

2021 ◽  
pp. 146442072110124
Author(s):  
Asim Iltaf ◽  
Fahd Nawaz Khan ◽  
Tauheed Shehbaz ◽  
Massab Junaid
Keyword(s):  
Mechanical Properties ◽  
Residual Stresses ◽  
Fusion Zone ◽  
Welded Joint ◽  
Weld Zone ◽  
Martensitic Transformations ◽  
Inert Gas ◽  
Physical Chemical ◽  
Pile Up ◽  
Compressive Residual Stresses

The microstructure and defects in the weld zone affect the weldment characteristics. One way to improve the microstructure and reduce the defects in the weld zone is by using a filler during welding which influences the physical, chemical, and mechanical properties of the manufactured component. In the present study, tungsten inert gas (TIG) was used to weld Ti-5Al-2.5Sn alloy using different titanium alloy fillers; Ti-6Al-4V, Ti-5Al-2.5Sn, and autogenous weldments were also produced. The welded joints were characterized in terms of their microstructure, mechanical properties, and residual stresses in its various regions. The weldment with Ti-6Al-4V as filler exhibited a higher proportion of α′ martensite in fusion zone, as compared to the welded joint with Ti-5Al-2.5Sn alloy as filler, owing to the higher proportions of β stabilizers present in Ti-6Al-4V alloy. The α’ martensite was present in basketweave and acicular morphology in all the weldments, with and without fillers. Ti-6Al-4V filler welded joint showed higher tensile strength (approximately 1144 MPa) and relatively higher hardness than Ti-5Al-2.5Sn filler welded joint (approximately 1027 MPa) and autogenous weldment (approximately 770 MPa), due to increased amount of martensite in its fusion zone. As compared to the weldment produced with Ti-5Al-2.5Sn filler, the welded joint produced without filler and with Ti-6Al-4V as a filler had more compressive residual stresses at surface (approximately 25% higher), leading to less amount of pile up after nanoindentation. This was attributed to the generation of compressive strains due to martensitic transformations in the fusion zone of both these weldments.

Effect of heat on microstructural, mechanical and electrochemical evaluation of tungsten inert gas welding of low-nickel ASS

2018 ◽  
Vol 65 (6) ◽  
pp. 605-615 ◽  
Author(s):  
Ankur V. Bansod ◽  
Awanikumar P. Patil ◽  
Sourabh Shukla
Keyword(s):  
Heat Input ◽  
Weld Zone ◽  
Inert Gas ◽  
Ferrite Content ◽  
Tungsten Inert Gas Welding ◽  
Content Type ◽  
Δ Ferrite ◽  
Passivation Current Density ◽  
Electrochemical Evaluation ◽  
Scanning Electron

Purpose The purpose of the study is to evaluate Cr-Mn ASS weld using different heat inputs for its microstructure, mechanical properties and electrochemical behavior. The microstructural examination used optical and scanning electron microscopy. It was observed that ferrite content decreases with increasing heat input. The length of dendrites, inter-dendritic space and volume of lathy ferrite increase with increasing heat input. The increasing heat input caused grain coarsening near the fusion boundary and produced wider heat-affected zone (HAZ). It also decreases hardness and tensile strength. This is attributed to formation of more δ ferrite in the weld. The electrochemical evaluation suggested that the δ ferrite helps in improving the pitting potential in 3.5 per cent NaCl solution saturated with CO2. Whereas in 0.5-M H2SO4 + 0.003-M NaF solution, higher passivation current density was observed because of dissolution of dferrite. The interphase corrosion resistance decreased with increasing heat input. Design/methodology/approach The Cr-Mn austenitic stainless steel or low-nickel ASS was procured in form of 3-mm sheets in rolled condition. The tungsten inert gas welding was performed at three different heat inputs (100 A, 120 A and 140 A), argon as shielding gas with a flow rate of 15 L/min. Different welded regions were observed using optical microscope and scanning electron microscope. Electrochemicals test were performed in solutions containing 3.5 per cent NaCl with saturated CO2 solution and 0.5 M sulfuric acid + 0.003 M NaF at a scan rate of 0.1667 mV/s at room temperature (30 °C ± 1 °C) using a potentiostat. Findings The test steel Cr-Mn ASS is suitable with the selected electrode (308 L) and it produces no defects. Vermicular ferrite and lathy ferrite form in welds of various heat inputs. The increase in heat input reduces the formation of lathy ferrite. The width of HAZ and un-mixed zone increases with increase in heat input. The weld zone of low heat input (LHI) has the highest hardness and tensile strength because of higher δ ferrite content and small grain size in the weld zone. The hardness at high heat input (HHI) is found to be lowest because of grain coarsening in the weld. With increase in δ ferrite, the pitting resistance increases. In 0.5-M sulfuric acid + 0.003-M NaF, the increase in ferrite content reduces the passivation current density. Interphase corrosion resistance increases with increase in δ ferrite content as higher per cent degree of sensitization was observed in LHI welds as compared to medium heat input and HHI welds. Originality/value This work focuses on welding of ASS by tungsten inert gas welding at different heat inputs. Welding is a critical process for joining metals in most of the fabrication industries and proper heat input is required for getting desired microstructure in the weld metal. This would highly affect the strength and corrosion behavior of the alloy. This paper would give an understanding of how the change in heat input by tungsten inert gas welding affects the microstructural and corrosion behavior in the weld metal.

Effects of Al-Mg wire replacing Al-Cu wire on the properties of 2219 aluminum alloy TIG-welded joint

2021 ◽  
pp. 2150139
Author(s):  
Dengkui Zhang ◽  
Aiping Wu ◽  
Yue Zhao ◽  
Jiguo Shan ◽  
Zhandong Wan ◽  
...  
Keyword(s):  
Aluminum Alloy ◽  
Tensile Properties ◽  
Welded Joint ◽  
Weld Zone ◽  
Inert Gas ◽  
Strengthening Phase ◽  
Alloying Element ◽  
Alloying System ◽  
2219 Aluminum Alloy ◽  
Solidification Cracks

The effects of Al–Mg wire replacing Al–Cu wire on the microstructure, microhardness and tensile properties of 2219 aluminum alloy tungsten inert gas (TIG)-welded joints were studied. Comparing joints with Al–Cu wire, the capping welds of joints with Al–Mg wire can be strengthened by the introduction of Mg-containing strengthening phase and the hardness can be significantly improved. However, for joints with Al–Mg wire, both the solidification cracks caused by inappropriate control of alloying element content and the continuous brittle phases at grain boundaries around the weld zone (WZ) can result in the reduced tensile properties. The crack-free weld can be obtained by adjusting the alloying system of WZ. Furthermore, the geometry of WZ also affected the tensile properties of joints with Al–Mg wire.

Microstructure and mechanical characterization of tungsten inert gas-welded joint of AA6061 and AA7075 by friction stir processing

2021 ◽  
pp. 146442072110078
Author(s):  
Husain Mehdi ◽  
RS Mishra
Keyword(s):  
Tensile Strength ◽  
Wear Resistance ◽  
Friction Stir Processing ◽  
Welded Joints ◽  
Welded Joint ◽  
Stir Zone ◽  
Inert Gas ◽  
Tungsten Inert Gas Welding ◽  
Friction Stir

In this work, the effect of friction stir processing (FSP) on tungsten inert gas welding (TIG) has been observed to improve mechanical properties and wear resistance behavior of TIG-welded joint of AA7075 and AA6061. The TIG-welded joints were processed by FSP at various tool rotational speeds of 700, 800, 900, 1000, and 1100 r/min with a constant feed rate of 70 mm/min and tilt angle of 1°. The maximum joint efficiency of 92.81% was observed in TIG + FSP-welded joint with filler ER5356 at a rotational tool speed of 1100 r/min. The maximum tensile strength of 284 MPa was observed in TIG + FSP-welded joint with filler ER5356, whereas the minimum tensile strength of 124 MPa was observed in the TIG weldment with filler ER4043. The cleavage facets, tears ridges, and large dimples were observed in fractured specimens of TIG-welded joints, whereas fine and equiaxed dimples were observed in TIG + FSP-welded joints. The maximum micro-hardness of 137 HV in the stir zone was observed in TIG + FSP-welded joint at a rotational tool speed of 1100 r/min. Due to intense precipitate (MgZn2) kept in the stir zone with filler ER5356, the TIG + FSP-welded joints using filler ER5356 have superior wear resistance compared to TIG and TIG + FSP-welded joint with filler ER4043.

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