Papers by Keyword: Friction Welding

Abstract: Ship transport continues to be the most economical intercontinental means of transportation, which is becoming more and more under observation due to increasing international environmental protection regulations. In order to protect the marine biotope, the government is introducing stricter exhaust emission regulations, which mean the further development of low-emission large engines and thus make the development of new combustion chamber components indispensable. This paper presents FE simulations of a friction welding process for two metallic materials, which are being developed as part of a BMWi joint project for the production of innovative combustion chamber components. In addition, the first results of the simulations and their comparison with real tests are presented.

Abstract: This paper considers the results of studies of the welded joints formation in conventional friction welding of pieces with different-sized cross sections. The features of the formation of joints associated with the asymmetry of the temperature field in the pieces are defined. The results of studies of the main parameters of the welding process are given which influence on the appearance, the microstructure of the joints and the valve after the stamp. The optimum parameters of the welding mode are set; recommendations are given.

Abstract: Friction welding of stainless steel to titanium with aluminum insert metal was investigated to improve the mechanical properties of the joints. Two different methods were used to insert the aluminum as a barrier between to substrates. The process parameters were found to be different for these two methods to obtain the sound welds. The friction welds between stainless steel and titanium with aluminum insert prevented the formation of brittle intermetallic compounds in the weld interface. A new intermetallic compounds such as AlTi and Al₃Ti were formed between titanium and aluminum insert metal interface which are more ductile than the FeTi and CrTi intermetallic compounds. The joints characterized that the aluminum insert metal improved the metallurgical reaction at the weld interfaces thus indicates the results of decrease in microhardness of the intermetallic compounds which have major influence on the strength of the joints. The tensile strength of the aluminum insert welds was higher than the direct joints between the stainless steel and titanium. Higher tensile properties were attained at higher upset pressure condition due to the effect of higher force upon the welded materials and the remnant narrower thickness of insert metal.

Abstract: Rotary friction welding (RFW) was used in the current study to join the dissimilar metals AA7020-T6 aluminium alloy and 316L steel. Neutron diffraction was performed to investigate the texture gradient around the weld line and to map the residual stress over the whole specimen. The texture analysis showed a weak shear component near the bond line of AA7020-T6-T6 side which indicated a plastic deformation of AA7020-T6 during welding. The shear bands were also observed in optical microstructures. Relatively high tensile residual stresses were observed near the bond line on the AA7020-T6 side, which were in-homogeneously distributed from the perimeter to the rod centre, while high compressive residual stresses were found in the sample centre at the bond line in the 316L steel.

Abstract: The objective of this experiment was to investigate deformation behavior of friction welded aluminium AA6063/alumina. Effect of welding speed on microstructural change and temperature gradient were determined. The result showed effects of welding speed on temperature and grains flow. Microstructures at the interfaces in all conditions exhibited recrystallised grains and hot deformation characteristic. Areas of Heat affected zone (HAZ) decreased with increasing welding speed. Hardness of recrystallised AA6063 grains decreased approximately by 30%. Increasing in amount of deformation increased the fully welded interface areas improving bonding strength of the weld.

Abstract: Aluminum alloys are widely used in engineering structures and components where light weight or corrosion resistance were required. Friction welding is classified as a solid-state welding process where metallic bonding is produced at temperatures lower than the melting point of the base metals. Friction time, friction pressure, forging time, forging pressure and rotation speed are the most important parameters in the friction welding process. The Response Surface Methodology (RSM) is used to optimize the process parameter and also useful in developing a proper approximation for the right functional relationship between independent variables and the response variable that may differentiate the nature of the joints. The empirical relationships are developed with the help of ANOVA design matrix to obtain the maximum tensile strength in the joints. The integrity of the joints are evaluated by Optical Microscopy (OM) and Energy Dispersive X-ray Analysis (EDAX) in this research work.

Abstract: In the paper there are presented experimental results concerning mechanical characteristics of friction-welded joints in comparison with electron beam welded joints, made by 20VNiMoCr120 heat-resistant steel, which are part of some elements working at high pressure and temperature. The paper represents a study which suggests non-conventional welding and heat-treatment procedures for water and steam-supply pipes, large cylindrical recipients with high values of wall thickness, boiler pipes, steam turbines which compose thermo-energetic installations, in order to prevent failure appearance. The actual level of development in all activity fields proves the fact that on top of the performance and modernism, technological products and processes must assure a high reliability. All the results and experimental researches are obtained by the first author in her PhD Thesis.

Abstract: The aim of this study was to test the connections of wastewater pipes with sockets. The connections are made by friction welding. In the production process, the pipe is fixed and the socket is rotated. Then, the rotating socket is forced onto the pipe. The heat necessary for the connection elements is produced by the friction of the contact surfaces with use of a suitable force. The effectiveness of the sealing process depends mainly on the holding force, temperature, and duration of the process. Figure 1 shows a cross section model of the pipe connected to the socket. The area includes two notches in the welded pipe.

Abstract: In this research work, the friction welding of AISI 1020 grade steel joints are fabricated to predict the minimum Vickers hardness in the joints. The response surface methodology was used to optimize the friction welding parameters in this study. RSM is a collection of mathematical and statistical techniques that are helpful for designing a set of experiments, analyzing the optimum combination of input process parameters, developing a mathematical model, and expressing the values graphically. Therefore, the response surface methodology has been utilized to optimize the friction welding process parameter with the help of ANOVA design matrix. The microstructures analyzed were carried out for the optimized condition joint.

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.