Papers by Keyword: Friction Welding

Abstract: In this work, frictions welding of AISI 1035 grade steel rods of 12 mm diameter were investigated with an aim to predict the value of tensile properties. Welds made with various process parameter combinations were subjected to tensile tests. Here, the three factors, five levels, central composite, rotatable design matrix are worn to limit the number of experiments. The mathematical models were developed by response surface method (RSM). The adequacies of the models were checked through ANOVA technique. From developed mathematical models, ultimate tensile strength (UTS) of the joints can be predicted by means of 95 percent confidence level. The integrity of the joints has been investigated using optical microscope.

Abstract: In this work, friction welding of AISI 52100 grade steel rods of 12 mm diameter was investigated to predict the value of tensile strength. The Joints made with various process parameter combinations were subjected to tensile tests. The primary process parameters are considered in ratios (friction pressure/friction time, forging pressure/forging time, rotational speed/sec). This is done to make as three factors. Here, the three factors, five levels, central composite, rotatable design matrix are worn to optimize the required number of experiments. The Empirical relationships were developed by Response Surface Method (RSM). The adequacy of the models was checked through ANOVA technique. Through using the developed Empirical relationship, Ultimate Tensile Strength (UTS) of the joints can be predicted by means of 95% confidence level.

Abstract: Friction welding is an economical solid state joining process which has gained industrial acceptance for producing dissimilar joints with light weight applications. In this work continuous drive friction welding was employed to produce AA6061-T6/AA2024-T6 joints. The process parameters which influence the quality characteristics of the joint like the frictional pressure, upset pressure, rotational speed and burn off length were varied in three levels and the experimental trials were designed by Taguchi’s L₉ orthogonal array. Yield strength, ultimate strength and micro-hardness in the weld area were observed as the responses for the various trials. Weighted S/N (WSN) ratio was calculated for each trial by utilizing the weights generated by simulated annealing (SA) algorithm. The optimal levels were sorted out by taking the WSN ratio as a measure of performance and a confirmation experiment was conducted for validation. The results of ANOVA had revealed the significant contribution of upset pressure in affecting the quality characteristics.

Abstract: The combination of aluminum and titanium alloys allows for designing lightweight structures with tailor-made properties at the macroscopic global as well as at the microscopic scale. In this context both co-extrusion and friction welding offer a great potential for advanced solutions for products with material combinations of aluminum and titanium. While titanium alloys show particular high mechanical strength and good corrosion resistance, aluminum alloys provide a considerable high specific bending stiffness along with low materials costs. Since the mechanical properties of metallic composites highly depend on the existence and formation of the intermetallic layer in the bonding zone compounds were processed by co-extrusion and friction welding and subsequent heat treatment to investigate the strength and the composition of the bonding zone. The results of friction welded samples concerning the intermetallic layer that was formed during heat treatment were compared with those directly after the co-extrusion. In this layer an enrichment of elements which origin from the aluminum alloy, particularly silicon, was observed. The layer was characterized by optical microscopy, scanning electron microscopy as well as electron probe micro analysis. The mechanical properties were determined by tensile tests.

Abstract: SSM 356 aluminum alloys was obtained from a rheocasting technique named gas induced semi solid process has globular structure on base. The friction welding method conserve microstructure that is similar to the original structure of the base material a globular structure. It is also found that a rotational speed of 1750 RPM, burn of Length of 3.2 millimeters and welding time (upset time) of 30 second can produce a very good weld. The results of the investigation have shown that a have average hardness in the range 58.13 HV.

Abstract: Dissimilar metal joints of stainless steel to titanium find extensive industrial applications especially in the nuclear industry. However, it is well known that fusion welding of stainless steel to titanium is difficult because of the formation of brittle intermetallic compounds and the associated problems. To avoid this, welding processes or techniques with high reliability and productivity for these dissimilar materials are demanded. In the present work, joints comprising of 304 stainless steel and commercially pure titanium were produced by friction welding using nickel as interlayer. Investigation on the mechanical properties of the joints shows the occurrence of highest hardness value at the interface of titanium and nickel interlayer. X-ray diffraction studies confirmed the presence of various types of intermetallic compounds at the interface of the welded joint. The tensile strength of the joint varies with the thickness of nickel interlayer used. Joints having maximum strength equals to 72% of that of titanium base metal could be produced. In all the joints, tensile failure occurred at Ti-Ni interface due to the presence of the intermetallic compounds at this interface. Fracture surface analysis reveals that the tensile fracture path is along the intermixing zone of titanium and nickel interlayer.

Abstract: Many critical applications in chemical equipment, aircraft and ordinance demand a material of construction with high strength and good corrosion resistance. Frequently the strength requirement exceeds that obtainable with austenitic or ferritic stainless steel and it is necessary to use one of the martensitic stainless steels. Since martensitic stainless steels are structural materials, weldability has been an important consideration in their development. AISI 431 is one of the most potentially attractive steels in this class used extensively for parts requiring a combination of high tensile strength, good toughness and corrosion resistance. Although this material has been used for many years, little information is available on the welding behavior of these steels. Further, data on electron beam (EB) welding and solid state welding process like friction welding are scarce. The lack of knowledge constitutes a potential drawback to the more widespread use of these steels. Hence, a study has been taken up to develop an understanding on the electron beam welding and friction welding aspects of martensitic stainless steel type AISI 431. Various kinds of post weld heat treatments (PWHT) were investigated to determine their influence on microstructure and mechanical properties. Weld center in EB welding resulted a cast structure consists of dendritic structure with ferrite network in a matrix of un-tempered martensite. In friction welding, the weld center exhibited thermo-mechanical effected structure consists of fine intragranular acicular martensite in equiaxed prior austenite grains. In both the welding processes, post weld tempering treatment resulted in coarsening of the martensite which increases with increase in tempering temperature. In the as-weld condition, welds exhibited high strength and hardness and poor impact toughness. Increase in impact toughness and decrease in strength and hardness is observed with an increase in tempering temperature. The hardness of EB welds increased with increase in the austenitizing temperature up to 1100 °C and a marginal decrease thereafter was observed. Double austenitization after double tempering resulted in optical mechanical properties i.e., strength, hardness and toughness.

Abstract: he macro fracture of broken drill pipe friction welded joints and characterizations of microstructure were performed by SEM and XRD, and tested its hardness. The results suggested that the large area of “gray leaf spot” (composition: Fe₃O₄) which is on friction welded joints is the main reason causing the drill pipe brittle fracture. In order to avoid excessive “gray leaf spot” defects during the friction welding, put forward practical recommendations.

Abstract: The propeller shaft of rear-wheel drive vehicle is an axis which transfers power from an engine to rear-wheel through differential gear box. In this study, we studied the properties of friction welding required to produce the aluminum propeller shaft of lightweight rear-wheel-drive vehicle. We studied welding property to apply Al 7075-T6 aluminum yoke to automobile connects driving shaft and differential gear box. Here, solid phase friction welding method was used. In friction welding process, the principal parameter is spindle speed, up-set pressure and up-set time. We analyzed variable characteristics of friction welding strength according to the change of the spindle rate and up-set pressure. Friction welding strength was analyzed with ultimate tensile strength test with universal testing machine (UTM). The Al 7075-T6 was used as the round bar of the diameter of 25mm. The ultimate tensile strength was 552.3 MPa. It is 94% of ultimate tensile strength of pure Al 7075-T6 material. The main parameters of characteristics are discussed in detail based on analysis of the main effects plot and multi-vari chart. Finally, the core factors to get the maximum effect of friction welding investigated.

Abstract: Bimetallic welds made between ferritic steels and austenitic stainless steels are conventionally fabricated using arc welding procedures such as Tungsten Inert Gas, Metal Inert Gas, Shielded Metal Arc Welding and Submerged Arc Welding. However friction welding provides a new and unique solid state approach for joining many similar and dissimilar materials, which may not be possible to join by other welding techniques available without adding any external filler metal. This approach is mostly used in joining of dissimilar materials. The reason for increased utility being the absence of any external filler material which may otherwise add to the heterogeneity of the weld structure. In this paper, the fabrication and effect of friction welding parameters on mechanical-micro structural changes of bimetallic weld joints has been discussed. An attempt has also been made to relate the effect of friction welding parameters on the peak temperature values taken near faying surface and micro hardness changes measured in various zones of weld.