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Preliminary Investigations of Structure and Properties of TIG Welded Ti-6Al-4V Alloy

Dewangan Saurabh, Ranjan Raushan, Chattopadhyaya Somnath, Gope Deepak, Bogdan-Chudy Marta

Advances in Science and Technology. Research Journal

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2021

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Vol. 15, no 1

156--165

EN

The titanium (Ti) and its alloys are taken into interest for commercial purpose due to its low density, high yield strength and high corrosion resistance properties. The present work deals with microstructural observation and mechanical property analysis of tungsten inert gas (TIG) welded Ti-6Al-4V alloy joints. For the purpose, two different set of plates were welded at same current and voltage, i.e., 190 A and 24 V, by the TIG welding technique. A critical analysis of the microstructure and mechanical properties like tensile strength and hardness of the welded Ti-6Al-4V plates was carried out in this work. It was found that both plates showed different behavior during the tension test. Plate 1 had 464.54 MPa of tensile stress and it broke at the welded joint. Plate 2 was unaffected at the welded zone but was broken at the base metal zone. The second plate had tensile strength of 501.83 MPa. According to the hardness test, both the welded plates possessed the highest hardness at the welded zone. However, plate 2 showed approximately 10% higher hardness than that of plate 2. A proper inter-relationship was observed between the mechanical behavior and microstructural appearance. The microscopic view of the welded joints revealed the presence of α, β and martensitic-α phases.

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Numerical Modeling of Superplastic Punchless Deep Drawing Process of a TI-6AL-4V Titanium Alloy

Skrzat Andrzej, Wójcik Marta

Advances in Science and Technology. Research Journal

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2020

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Vol. 14, no 1

127--136

EN

The numerical results of superplastic punchless deep drawing of the Ti-6Al-4V titanium alloy were presented in this paper. The material behavior subjected to the forming process was characterized by deformation-microstructure constitutive equations including the grain growth. Superplastic stress-strain characteristics used in the numerical simulations were computed with the application of authorial program. The explicit integration scheme is used in solving differential equations. The numerical simulations of the super-elastic deep drawing were made with finite element method analysis. The von Mises stress distribution in the blow-forming process was obtained. The possible faults of extrusions caused by the improper load history as well as unsuitable pressure were also presented in this paper. The numerical simulations included in this research allow for the proper choice of material and drawing parameters which can help to optimize the superplastic forming process.

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Fatigue Characteristics of Selected Light Metal Alloys

Cieśla M., Junak G., Marek A.

Archives of Metallurgy and Materials

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2016

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Vol. 61, iss. 1

271--274

EN

The paper addresses results of fatigue testing of light metal alloys used in the automotive as well as aerospace and aviation industries, among others. The material subject to testing comprised hot-worked rods made of the AZ31 alloy, the Ti-6Al-4V two-phase titanium alloy and the 2017A (T451) aluminium alloy. Both low- and high-cycle fatigue tests were conducted at room temperature on the cycle asymmetry ratio of R=-1. The low-cycle fatigue tests were performed using the MTS-810 machine on two levels of total strain, i.e.Δεc= 1.0% and 1.2%. The high-cycle fatigue tests, on the other hand, were performed using a machine from VEB Werkstoffprufmaschinen-Leipzig under conditions of rotary bending. Based on the results thus obtained, one could develop fatigue life characteristics of the materials examined (expressed as the number of cycles until failure of sample Nf) as well as characteristics of cyclic material strain σa=f(N) under the conditions of low-cycle fatigue testing. The Ti-6Al-4V titanium alloy was found to be characterised by the highest value of fatigue life Nf, both in lowand high-cycle tests. The lowest fatigue life, on the other hand, was established for the aluminium alloys examined. Under the high-cycle fatigue tests, the life of the 2017A aluminium and the AZ31 magnesium alloy studied was determined by the value of stress amplitude σa. With the stress exceeding 150 MPa, it was the aluminium alloy which displayed higher fatigue life, whereas the magnesium alloy proved better on lower stress.