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Journal ArticleDOI: 10.1080/02286203.2019.1700089

Numerical prediction of temperature distribution and residual stresses on plasma arc welded thin titanium sheets

04 Mar 2021-International Journal of Modelling and Simulation (Taylor & Francis)-Vol. 41, Iss: 2, pp 146-162
Abstract: The residual stresses are responsible for most of the failure of weldments in nuclear industry and the temperature distribution is the key measure to predict these residual stresses. The residual s...

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Topics: Residual stress (67%), Residual (58%), Plasma arc welding (52%)

17 results found

Open accessJournal ArticleDOI: 10.3390/APP10103569
01 May 2020-Applied Sciences
Abstract: In this study, the effect of oxygen in the shielding gas on the material flow behavior of the weld pool surface was discussed to clarify the dominant driving weld pool force in keyhole plasma arc welding (KPAW). To address this issue, the convection flow on the top surface of weld pool was observed using a high-speed video camera. The temperature distribution on the surface along keyhole wall was measured using the two-color pyrometry method to confirm the Marangoni force activity on the weld pool. The results show that the inclination angle of the keyhole wall (keyhole shape) increased especially near the top surface due to the decrease in the surface tension of weld pool through surface oxidation when a shielding gas of Ar + 0.5% O2 was used. Due to the change in the keyhole shape, the upward and backward shear force compositions created a large inclination angle at the top surface of the keyhole. From the temperature measurement results, the Marangoni force was found to alter the direction when 0.5% O2 was mixed with the shielding gas. The shear force was found to be the strongest force among the four driving forces. The buoyant force and Lorentz force were very weak. The Marangoni force was stronger than the Lorentz force but was weaker than shear force. The interaction of shear force and Marangoni force controlled the behavior and speed of material flow on the weld pool surface. A strong upward and backward flow was observed in the case of mixture shielding gas, whereas a weak upward flow was observed for pure Ar. The heat transportation due to the weld pool convection significantly changed when only a small amount of oxygen was admixed in the shielding gas. The results can be applied to control the penetration ratio in KPAW.

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Topics: Weld pool (64%), Shear force (58%), Shielding gas (57%) ... read more

5 Citations

Open accessJournal ArticleDOI: 10.1016/J.MATPR.2020.08.249
Abstract: In the existence era, the usage and need for Titanium (Ti) alloys has been increased for manufacturing weight-less products of machine-made automobile and aerospace tools with increased application of multi-material design. When compared to conventional manufacturing techniques, titanium and its alloys are categorized through better machinability, enhanced melting of temperature, great strength-to-weight ratio, lower thermal conductivity, and increased reaction to oxygen. In recent years, numerous assemblage systems have been pondered to manufacture Ti alloys but Laser Beam Welding (LBW) opens a worthwhile possibility towards other techniques for joining of titanium and alloys in industries due to its adaptability, great and explicit heat input, tractability. In optimal process circumstances, however there occurs a problem such as poor elongation and resistance to corrosion joined with lower fatigue properties, the strength-to-weight ratio of laser welded titanium alloys found to be approaching to unique material. In this study, a small review on the fatigue behaviour of laser welding titanium alloys has been analysed to enhance its mechanical properties, influence of process parameters, fracture mechanisms.

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Topics: Titanium alloy (61%), Laser beam welding (60%), Welding (57%) ... read more

1 Citations

Proceedings ArticleDOI: 10.1063/5.0025152
29 Oct 2020-
Abstract: Extrusion is the important manufacturing process and many components have been manufactured. Extrusion load play the major role for that the selection of die angle. A pilot study has been conducted for selecting a suitable die design for the present work. The selection of the semidie angle has been determined for the die of inlet diameter 12 mm and outlet diameter 8 mm. Hot die steel (H-13) is used as the die material for this study.

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Topics: Extrusion (56%), Die (manufacturing) (55%)

1 Citations

Proceedings ArticleDOI: 10.1063/5.0025083
29 Oct 2020-
Abstract: In this novel study for the most part paying attention regarding flexural strength in addition to flexural modulus of chicken feather fiber participated fiber reinforced polyester composite. There are three different length of fiber such as 5mm, 10mm, 15mm and 20mm with three different percentage of chicken feather fiber with neat polyester produce 12 composites. The flexural strength and flexural modulus experiments were accomplished for each and every specimen and the subsequent values noted to recognize the appropriate specimen composition and corresponding length of fiber.

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Topics: Flexural modulus (72%), Flexural strength (68%), Fiber (57%)

Proceedings ArticleDOI: 10.1063/5.0025346
29 Oct 2020-
Abstract: Nowadays the automobile industry is largely driven by designs that complies with the laws and regulations governed by environment concerns. For instance, to counter noise pollution designer came up with the idea of muffler that considerably reduces the noise produced by the engine. An effort has been made to try and compare different models of a reactive muffler through case studies after cumulatively incorporating various changes that are generally considered beneficial. This paper compares the stock muffler with new designs by considering transmission loss as the deciding factor since it is a property of the geometry alone. The more the transmission loss the better the muffler is at attenuating the noise generated by the engine. However, another important factor that should be considered when designing a muffler is the Backpressure it creates on the engine as backpressure negatively impacts its performance. The design with the highest transmission loss along with a controlled backpressure is declared as the most effective design.

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Topics: Muffler (61%)


22 results found

Journal ArticleDOI: 10.1016/J.COMMATSCI.2005.07.007
Dean Deng1, Hidekazu Murakawa1Institutions (1)
Abstract: A computational procedure is presented for analyzing temperature fields and residual stress states in multi-pass welds in SUS304 stainless steel pipe. Based on the ABAQUS software, uncoupled thermal–mechanical three-dimensional (3-D) and two-dimensional (2-D) finite element models are developed. The finite element models are employed to evaluate the transient temperature and the residual stress fields during welding. Firstly, a 3-D model is developed to simulate the temperature fields and welding residual stresses. Secondly, based on the characteristics of the temperature fields and the welding residual stress fields, a 2-D axisymmetric model is also developed. The simulated result shows that the 2-D axisymmetric model can be effectively used to simulate the thermal cycles and the welding residual stresses for SUS304 stainless steel pipe. Using the 2-D model, a large amount of computational time can be saved. In this study, experiments are also carried out to verify the effectiveness of the proposed numerical models. The results of both 3-D model and 2-D model are in very good with the experimental measurements.

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Topics: Welding (62%), Residual stress (60%), Finite element method (51%)

453 Citations

Open accessJournal ArticleDOI: 10.1016/J.JMATPROTEC.2012.02.002
Abstract: With increasing emphasis on sustainability, additive layer manufacturing (ALM) offers significant advantages in terms of reduced buy-to-fly ratios and improved design flexibility. Plasma wire deposition is a novel ALM technique in which plasma welding and wire feeding are combined. In the present work, a working envelope for the process using Ti–6Al–4V was developed, and regression models were calculated for total wall width, effective wall width and layer height. The plasma wire deposition process is able to produce straight walls of widths up to 17.4 mm giving a maximum effective wall width after machining of 15.9 mm, which is considerably wider than competing processes. In addition, for Ti–6Al–4V the deposition efficiency averages 93% and the maximum deposition rate is 1.8 kg/h. Coarse columnar grains of β phase grew from the base during deposition, which transformed into a Widmanstatten structure of α lamellae on cooling. Bands were identified in the deposits, which had a repetitive basket-weave microstructure that varied in size. The strength measured by micro-indentation hardness of 387 HV on average is as much as 12% higher than the substrate. These preliminary results indicate that plasma wire deposition is likely to be a suitable process for the ALM of large aerospace components.

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329 Citations

Open accessJournal Article
01 Dec 1983-Welding Journal
Abstract: The solution of a traveling distributed heat source on a semi-infinite plate provides information about both the size and the shape of arc weld pools. The results indicate that both welding process variables (current, arc length and travel speed) and material parameters (thermal diffusivity) have significant effects on weld shape. The theoretical predictions are compared with experimental results on carbon steels, stainless steel, titanium and aluminum with good agreement. 25 references, 23 figures, 1 table.

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Topics: Arc welding (60%), Welding (58%), Thermal diffusivity (56%)

320 Citations

Journal ArticleDOI: 10.1016/S0308-0161(01)00047-3
S. Murugan1, Sanjai K. Rai1, P. V. Kumar1, T. Jayakumar1  +2 moreInstitutions (2)
Abstract: Welding is a reliable and efficient metal-joining process widely used in industry. Due to the intense concentration of heat in the heat source of welding, the regions near the weld line undergo severe thermal cycles, thereby generating inhomogeneous plastic deformation and residual stresses in the weldment. Plates of different thickness are used in industry and these plates are normally joined by multipass welding. In a multipass welding operation, the residual stress pattern developed in the material changes with each weld pass. In the present experimental work, thermal cycles and transverse residual stresses due to each pass of welding have been measured in the weld pads of AISI type 304 stainless steel and low carbon steel with 6, 8 and 12 mm thickness. X-ray diffraction method was used for residual stress measurements. The welding process used was the Manual Metal Arc Welding (MMAW) process. In this paper, the peak temperatures attained at different points during deposition of weld beads in stainless steel and low carbon steel weld pads are compared. The residual stress patterns developed, the change in the peak tensile stress with the deposition of weld beads, and the relation between the peak temperatures and the residual stresses in the weld pads are discussed.

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Topics: Heat-affected zone (70%), Welding (70%), Electric resistance welding (68%) ... read more

124 Citations