Search

This investigation aims to study the influence of friction pressure (FRNP) on the evolution of microstructure and tensile properties of Ti6Al4V alloy joints developed using linear friction welding (LFW) for aeroengine applications. The Ti6Al4V alloy plates of 6 mm thickness were joined using different levels of FRNP from 10 MPa to 30 MPa. The weld joint quality was analyzed employing stereo-zoom microscope. The microstructure of LFW joints was studied using optical (OM), scanning electron (SEM) and transmission electron microscope (TEM). The hardness and tensile properties were evaluated and correlated to the microstructure of joints. The fractographs were studied using SEM and correlated to the hardness. The LF welded Ti6Al4V joints made using the optimum level of FRNP of 20 MPa exhibited greater tensile strength (UTS) of 993 MPa, and elongation (EL) of 8%. It showed notch tensile strength (NTS) of 1073 MPa and notch strength ratio (NSR) of 1.041 revealing ductile fracture. The LF welded Ti6Al4V joints revealed 96.41%, 104.10% and 66.67% of UTS, NTS and EL of base metal. The greater smooth and notch tensile properties of joints are principally imputed to maximum refinement of alpha + beta grains at interface of joint.

This investigation aims to study the influence of friction pressure (FRNP) on the evolution of microstructure and tensile properties of Ti6Al4V alloy joints developed using linear friction welding (LFW) for aeroengine applications. The Ti6Al4V alloy plates of 6 mm thickness were joined using different levels of FRNP from 10 MPa to 30 MPa. The weld joint quality was analyzed employing stereo-zoom microscope. The microstructure of LFW joints was studied using optical (OM), scanning electron (SEM) and transmission electron microscope (TEM). The hardness and tensile properties were evaluated and correlated to the microstructure of joints. The fractographs were studied using SEM and correlated to the hardness. The LF welded Ti6Al4V joints made using the optimum level of FRNP of 20 MPa exhibited greater tensile strength (UTS) of 993 MPa, and elongation (EL) of 8%. It showed notch tensile strength (NTS) of 1073 MPa and notch strength ratio (NSR) of 1.041 revealing ductile fracture. The LF welded Ti6Al4V joints revealed 96.41%, 104.10% and 66.67% of UTS, NTS and EL of base metal. The greater smooth and notch tensile properties of joints are principally imputed to maximum refinement of alpha + beta grains at interface of joint. [ABSTRACT FROM AUTHOR]

The influence of friction pressure on welding quality when friction stud welding 1017 low carbon steel with AISI 304 austenitic stainless steel is investigated in this study. friction stud welding is employed in industrial applications instead of conventional welding processes Due to the friction welding process didn't need to reach the melting point of welded metals. Welding is performed on these dissimilar metals by utilizing a lathe machine with a load cell connected to a weight indicator and a manufacturing grip to fasten the plate at a rotating speed of 1600 RPM, a friction time of 20 seconds, and a friction pressure of (15, 20, and 25) MPa. After the welding procedure is completed, the specimens are subjected to tensile, torque, and hardness tests to evaluate the welding quality. In addition, optical microscope research was carried out to determine the microstructural aspects. The effect of friction pressure on welding quality was investigated based on the information generated from the results. The increase of friction pressure during the process from 15 MPa to 25 MPa leads to an increasing ultimate tensile strength from 203 MPa to 210 MPa approximately. Also, the torque values raised from 179 N.m to 198 N.m in the same case. [ABSTRACT FROM AUTHOR]

The influence of friction pressure on welding quality when friction stud welding 1017 low carbon steel with AISI 304 austenitic stainless steel is investigated in this study. friction stud welding is employed in industrial applications instead of conventional welding processes Due to the friction welding process didn't need to reach the melting point of welded metals. Welding is performed on these dissimilar metals by utilizing a lathe machine with a load cell connected to a weight indicator and a manufacturing grip to fasten the plate at a rotating speed of 1600 RPM, a friction time of 20 seconds, and a friction pressure of (15, 20, and 25) MPa. After the welding procedure is completed, the specimens are subjected to tensile, torque, and hardness tests to evaluate the welding quality. In addition, optical microscope research was carried out to determine the microstructural aspects. The effect of friction pressure on welding quality was investigated based on the information generated from the results. The increase of friction pressure during the process from 15 MPa to 25 MPa leads to an increasing ultimate tensile strength from 203 MPa to 210 MPa approximately. Also, the torque values raised from 179 N.m to 198 N.m in the same case.

The aim of this study is to investigate the effects of the parameters such as friction pressure, friction time, forging pressure and forging time on mechanical and metallurgical properties of friction welded joints of inconel 713C and AISI 4140 material pair. Tensile tests and hardness tests were carried out to determine the mechanical properties of welded joints. Following tensile tests, the fracture surfaces occurred in the joints were examined by scanning electron microscope (SEM), and the type of fracture and fracture surface characteristics were evaluated. Optical microscope and electron microscope were used to examine the metallurgical properties of welded joints. The tensile, hardness, and microstructure results were associated with the welding process parameters. It was concluded that the highest strength was obtained as 718 N/mm2 and there was a significant increase in hardness values in the thermomechanically affected zone (fully deformed zone) of all samples. In all welding tests, it was determined that the fracture location was on the side of AISI 4140 steel material. As a result of friction welded joints, while γ and γ′-Ni3(Al, Ti) phases were observed in the matrix, the formation of the γ′′-Ni3Nb phase at the grain boundaries was also determined by SEM-EDS analysis. Also it was shown that the carbides deposited at the grain boundaries are generally carbides formed by Nb. [ABSTRACT FROM AUTHOR]

The objective of this research was to investigate the effect of friction time and friction pressure on the tensile strength of the joining of two dissimilar materials, aluminum alloy AA6061 and carbon steel, with continuous drive friction welding process. Variations of friction times of 5 seconds, 7 seconds, 9 seconds, and 11 seconds, at each variation of friction pressures of 24 MPa, 32 MPa, and 40 MPa. Controlled variables in this friction welding process were rotational speed of 1600 rpm, upset pressure of 79 MPa which was applied for 60 seconds and diameter of friction surface of specimens which were 15 mm. The resulting strength of the bonding were than evaluated on the basis of tensile strength. Observations of temperature change during the welding process, the distribution of Vickers hardness values around the bonds area, and micro photographs, were used as support to the analysis. The results showed that the longer friction time was applied, the higher tensile strength of the bonds would be, until it began to decrease after a certain maximum value of the tensile strength had been reached. Increased of the tensile strength of the bonding did not occur linearly due to the variation of friction pressure at 9 seconds and 11 seconds of friction time. At 5 seconds and 7 seconds of friction time, increase of friction pressure caused a linear increase of tensile strength. Higher temperatures in the welding process increased the thickness of brittle layer at the bonds boundary. The increase of the brittle layer thickness causes decrease of the tensile strength of the bonds.

Copyright of Cotton Textile Technology is the property of Cotton Textile Technology Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The theoretical and experimental analyses of the friction welding pressure influence on the plastic deformation level and the quality of the friction welded joint are presented in this paper. The joint of the tempering and the High-Speed steel was realized by the friction welding. The objective was to relate the two basic process parameters - the friction and compacting pressures - to plastic deformation parameters during the friction welding of two the steels. The fact that materials are dissimilar additionally complicates the welding procedure and its analysis. The friction welding is a specific and complex process, since in the joint zone material is heated and plasticized with necessary action of the multi-step pressure to realize the joint. The total deformations in the axial and radial directions are directly dependent on the applied welding pressure. Considering that geometry and shape of the friction welded joint directly depend on the friction pressure, some welded joints' basic shapes obtained with various pressures are presented. The experimental investigation was conducted on cylindrical samples made of the two steels and the analysis of results served for establishing the influences of the friction and compacting pressures on changes of the steel samples dimensions and shapes. [ABSTRACT FROM AUTHOR]

Abstract: Friction pressure estimation is an important part of pipe and annular hydraulics useful for determining hydraulic horsepower requirements and the maximum wellhead pressure. For non-Newtonian fluids in laminar flow, the friction factor can be calculated with the Hagen–Poiseuille type equation. In turbulent flow, however, several correlations have been developed for smooth pipes. Many of these correlations are in the form of the Dodge–Metzner equation for flow in smooth pipes. The Dodge–Metzner correlation was developed using carbopol aqueous solution which is not used for oilfield operations. Previous studies on friction factor correlation comparison have been limited to the use of non-Newtonian fluid friction factor equations for smooth pipes neglecting the significant effect of pipe roughness on wellbore hydraulics. Generally, tubulars in oilfield applications have some degree of roughness which results in higher friction pressure than that for smooth pipes of the same size especially for less viscous fluids. A few studies have addressed the effect of roughness on friction pressure loss. In this study, friction factor correlations with relative roughness are compared with experimental measured friction factor data using a statistical approach as the basis for comparison. Further, equivalent diameter definitions for annular flow are evaluated to determine the friction factor–equivalent diameter combination that best describes the experimental data. The objective of this work is to recommend the non-Newtonian friction factor correlation that allows for accurate prediction of frictional pressure losses in rough pipes and annular sections. [Copyright &y& Elsevier]