Applied Mechanics and Materials Vols. 766-767

Abstract: The main objective of this work is to compare the weld strength of AA7075 aluminium alloy by conducting tensile test and impact test for various welding like TIG, MIG and FSW. Aluminium is one of the lightest available commercial metals with a density approximately one third that of steel or copper, thus making it the most earnestly used metal for Catamaran ferries, petroleum tankers and aircrafts. Having so many welding methods for joining AA7075 alloy, it is still unclear as to which welding method gives the better weld strength. This study shows the best suitable method of welding for AA7075 aluminium alloy for the suitable conditions specified. ANOVA is done to find the parameters that have highest influence on weld strength. The result shows that the parameter that has highest influence on weld strength is axial force.

Abstract: Limitation in penetration depth is a concern in conventional TIG welding. To improve penetration capability of TIG process, Flux Bounded TIG (FBTIG) has been developed. Stress corrosion cracking (SCC) behavior of FBTIG welds of aluminum alloy AA 2219 T87 is evaluated in 3.5 weight percent NaCl solution using Slow Strain Rate Test technique (SSRT) as per ASTM G129. SCC index defined as the ratio of the elongation of tensile tested specimen in NaCl to that of air is taken as a measure of the susceptibility to cracking. Based on the SCC index, it is concluded that the SCC resistance of FBTIG joints are good and comparable to that of conventional TIG welds.

Abstract: Rotary Friction welding is a process of solid state joining, broadly in shaft and pipe weld, in the field of automobile, defence, aeronautical, chemical and nuclear environment assembly pipe lines. Due to its some distinctive advantages similar to ease of fabricate, environmentally sociable, high fabrication value and appropriate for similar, dissimilar metal joint. Now a day’s Titanium alloy and stainless steel materials are very popular material in industrial application due to its high mechanical potency, and non-corrosive in nature. In this study an attempt was made to join commercial rod of Ti-6Al-4V and Stainless steel304L with some methods and evaluates the joint strength. Different intermediate metals are taking on in this process and the outcomes are witnesses. From that study the best method of in-between metal was analyzed by carry out mechanical and metallurgical test.

Abstract: The rotary type continuous friction welding process is a solid state joining process by mechanically. It produces a joint in the forging pressure contact with rotating and motionless workpiece. The solid state joining process it produces welds with reduced distortion and improved mechanical properties. The austenitic stainless steels are widely used in shipbuilding field, nuclear field and automobile field because of their special mechanical and metallurgical properties. In this work, friction welding of austenitic stainless steel rods of 10mm diameter was investigated with an aim to understand the influence of friction welding process parameters. The details of microstructure analysis using optical microscopy are discussed.

Abstract: The joining of ceramic to structural alloys has received much attention in recent years because of its potentially attractive properties. In the present investigation alumina which is a ceramic has been brazed with titanium alloy (Ti6Al4V) using KM72(Ag/Cu) filler material.The study has been carried out using CO₂ laser gas in argon inert atmosphere. Uniformity of the brazed joints has been observed in scanning electron micrographs. The elements and phases present at the joint interface have been characterized by EDX and XRD spectra analysis. As per the experimental observation, the phases present in the Ti6Al4V/KM72/alumina joint are Cu₃TiO₄, Cu₃Ti₂,CuO, Ti₂Cu, CuTi, and Cu₄Ti₃. The effect of brazing process parameters on the shear strength of the brazed joint has been studied and maximum shear strength observed at brazing power of 330 watts and speed 300 mm/min is 4±0.5MPa. Micro-hardness values of the brazed interface indicate that the interface is softer than the substrate.

Abstract: The friction welding method could be a solid state connection method that produces a joint within the forging force contact of revolving and stationary workpiece. The solid state connection method, it produces welds with reduced distortion and improved mechanical properties. The austenitic stainless steels are wide employed in completely different industrial applications like building, nuclear trade and automobile industries owing to their special mechanical and metallurgical properties. During this work, friction welding of austenitic stainless-steel rods of 10mm diameter was investigated with an aim to grasp the sensitivity of friction attachment method parameters. The details of microstructure analysis using optical microscopy are discussed.

Abstract: In this research work, friction welding (FW) of AISI 1020 grade carbon steel rods of 12 mm diameter was investigated with an aim to develop the empirical relationship to predict the minimum micro hardness for the process parameters. Welds are made with various process parameter combinations using ANOVA design matrix which were subjected to Vickers hardness tests. A microstructure analyses was carried out to acquire the joint efficiency. The heat affected zone of the microstructure has been shown for the optimized condition.Keywords:-Friction welding, AISI 1020 grade carbon steel, empirical relationship, Grain structure, Micro hardness.

Abstract: Resistance spot welding is widely used in automobile and rail car manufacturing industries. In this research work, resistance spot welded dissimilar joints of ferritic stainless steel and weathering steel sheets is investigated for mechanical and metallurgical properties. Ferritic stainless steel AISI 409M and weathering steel corten A (ASTM A 242) of 2mm thickness were used in this work. Spot welding was done at different current values, keeping other parameters such as electrode force, electrode tip diameter and weld time as constant. Test specimens were subjected to tensile shear test and micro hardness test to assess the mechanical properties of the weld joints. The influence of welding current on nugget growth, fusion zone hardness, peak load, and failure energy and failure mode during tensile shear test, was investigated at various current ratings. The results showed that, with increasing value of current, peak load increased correspondingly. Nugget shape was found to be near symmetrical. Nugget diameter was found to be increasing with increase in current, in expulsion free welds. Interfacial mode of failure was noticed at low current values, whereas, at higher current values, pull out mode of failure was observed. Presence of martensite was observed in the fusion zone. Micro hardness values at fusion zone were found to be more than that of both heat affected zones and base metals.

Abstract: The purpose of this study is to evaluate the mechanical and metallurgical properties of dissimilar metal weld joints between duplex stainless steel/Cold Reduced low carbon Steel (CRS) by Gas Tungsten Arc Welding (GTAW) process. The dissimilar 2 mm thickness plates of duplex stainless steel and cold reduced low carbon steel, conforming to AISI 2205 and IS 513_2008 CR2_D were butt welded by means of gas tungsten arc welding using argon as shielding gas. The butt welding joint arrangement was used for this experiment using E 309L electrode as filler metal. The joints were investigated for mechanical properties and microstructure. Tensile, Hardness and bend tests were carried out to evaluate the mechanical properties. Optical microscopy was used to explore the microstructure. The micro structural examination of the weld region revealed dendritic delta ferrite. Micro examination of DSS base metal revealed elongated grains of austenite (white) with ferrite (Brown). Micro examination of CRS base metal discloses deformed grains of ferrite present in the matrix. Fracture analysis was conducted for the failure part with Scanning Electron Microscope (SEM) and found ductile fracture occurred at CR steel side.

Abstract: Metal Matrix Composites are being widely used in numerous applications like aerospace, Automobiles, Consumer goods etc. However, machining of these composites are being faced a lot of drawbacks in terms of increases in thrust force, machined surface roughness and tool wear etc. due to reinforcements of high hardness. In this paper, thrust forces in drilling of Al6061/mica composites with 1 and 3 weight% are recorded from Dynamometer for analysis. Cutting tool material of Tungsten carbide coated with TiAlN with 8 mm diameter was used. Al 6061/Mica_p composites were scrutinized on cast surface with the help of optical microscope. Also, Thrust force was analysed for different Cutting Speed and feed. It can be concluded that, as weight% of mica increases Thrust forces were decreased.