Burn-off Length Research Articles

Joint Efficiency and Average Burn-Off Length of Friction Welded ABS Ter-Polymers

Joint Efficiency and Average Burn-Off Length of Friction Welded ABS Ter-Polymers

Characterization of the Polyetheretherketone Weldment Fabricated via Rotary Friction Welding.

Polyether ether ketone (PEEK) is frequently employed in biomedical engineering due to its biocompatibility. Traditionally, PEEK manufacturing methods involve injection molding, compression molding, additive manufacturing, or incremental sheet forming. Few studies have focused on rotational friction welding (RFW) with PEEK plastics. Based on years of RFW practical experience, the mechanical properties of the weldment are related to the burn-off length. However, few studies have focused on this issue. Therefore, the main objective of this study is to assess the effects of burn-off length on the mechanical properties of the welded parts using PEEK polymer rods. The welding pressure can be determined by the rotational speed according to the proposed prediction equation. The burn-off length of 1.6 mm seems to be an optimal burn-off length for RFW. For the rotational speed of 1000 rpm, the average bending strength of the welded parts was increased from 108 MPa to 160 Mpa, when the burn-off length was increased from 1 mm to 1.6 mm and the cycle time of RFW was reduced from 80 s to 76 s. A saving in the cycle time of RFW of about 5% can be obtained. The bending strength of the welded part using laser welding is lower than that using RFW, because only the peripheral material of the PEEK cylinder was melted by the laser.

Experimental investigations and effect of parameters on friction welded AISI 304 and Invar alloys

ABSTRACT It is challenging to achieve sound weld quality between dissimilar materials such as AISI 304 and Invar alloys with the help of the fusion welding process due to various weld defects like slag inclusion and misalignment. In current work, Invar alloys and AISI 304 material is welded with 12 mm diameter and 70 mm length on a commercial friction welding machine. Taguchi L9 orthogonal design is utilised for experiments, and an optimised parameter combination is identified. Machining parameters such as friction rotation RPM − 1100,1300,1500 rpm, frictional pressure 33,43,53 MPa, and burn-off length 4,5,6 mm are selected for the experiments. Forge pressure is not applied in experimental tests, and the tensile strength of the weld joint is evaluated for comparison. The findings revealed that the lower friction pressure up to 43 MPa resulted in higher tensile strength up to 517 MPa and refined grains in the microstructure. The higher friction pressure resulted in lower tensile strength due to non-homogeneous temperature distribution at the weld interface. The burn-off length shows significant effects on tensile strength results beyond 5 mm. The findings demonstratedthat the process could join dissimilar materials with enhanced mechanical properties.

Analysis on Bonding Interface during Solid State Additive Manufacturing between 18Cr-8Ni and 42CrMo4 High Performance Alloys

The need for additive manufacturing (3D printing) to create near net shape components from a wide variety of materials has grown in recent years. There are several additive manufacturing methods to build various parts by different materials. However, it is challenging to construct, the components with incompatible materials combination for high temperature and creep resistance using conventional methods. Consequently, the purpose of this research is to investigate the use of solid state welding (friction welding) in additive manufacturing (SSAM) of incompatible materials, namely alloy Cr18-Ni8 and 42CrMo4 low alloy alternative layers. The interface bonding strength must be strengthened to achieve the desired isotropic characteristics and high strength for the components. Due to the low temperature at the bonding interface, secondary phases cannot develop when solid state welding is used. In order to obtain the highest bonding strength, optimal process parameters were examined using design of experiments (DOE) with Box–Behnken design model and analysis of variance (ANOVA). The major process parameters of upset pressure, friction pressure and burn-off length were varied to obtain the optimal conditions. In addition, the bonded interfaces were examined by the microstructural characteristics as well as mechanical properties such as micro-hardness and bonding strength. The interface is made up of alloys intermixed with different zones such as a dynamically recrystallized zone and a thermomechanical affected zone. The intermixed layers revealed the migration of C and Mo to Cr18-Ni8 alloy and separated the Fe and Ni bands. The fractography analysis revealed ductile and slightly brittle fracture surfaces with a mixed mode. The relationship between bond strength and interface thickness was determined by studying the impact of interface thickness on bond strength.

Implementation of Exceptional Microstructures and Mechanical Properties of Structural Carbon Steel Tubes by Friction Welding

In this study, friction welding was applied to carbon steel tubes at a high speed condition to achieve an eco-friendly welding process and a superior mechanical performance. Friction welding is a very efficient process for joining materials without defects, especially with joint rods or tubes. For this study, cold drawn carbon steel tubes (AISI 1020) were introduced as the base material and successfully joined by friction welding. Friction welding was performed with parameters of a burn-off length (1, 2 and 5 mm). In order to analyze the welds, the electron backscattering diffraction method was introduced and observed the grain boundary characteristic distributions such as grain size, shape and orientation. To evaluate the relationship between the mechanical properties and microstructure, Vickers microhardness and tensile tests were introduced. As a result, the yield strength of the welds significantly increased relative to the base material at all conditions, and which derived from the microstructure development like a refined acicular ferrite grains through the dynamic recrystallization during the welding. Consequently, we suggest the optimum conditions of the friction welding with the interdependence of the microstructures and mechanical properties in this study. This demonstration substantially offers the possibility of an eco-friendly environment and superior tube welding quality without any defect and harmful gases at the high speed welding process as well as at the lowest cost. This technology can be extended to mass production processes with exceptional benefits for various industries.

Investigation of the friction weldability of an AlSi10MnMg-alloy reinforced with 30 Vol.-% silicon carbide particles with the adequate monolithic material

Due to their positive properties, AMC materials represent a current trend in industrial applications and thus a major research focus. But currently their difficult machinability limits a full establishment. Therefore, suitable joining processes are needed which allow a targeted and punctual use of the AMC-materials and thus minimize the machining effort.This paper presents a feasibility study of a direct material bond between an AlSi10MnMg-alloy reinforced to 30 Vol.-% with silicon carbide particles and the adequate monolithic material by using friction welding. For this purpose, in addition to the general feasibility, the achievable strengths are evaluated and the underlying material behavior as well as metallurgical processes are analyzed.As a result, the principle friction weldability of the used AMC material is demonstrated. Essentially, the joint results from a material bond between the aluminum alloy and the matrix material. The reinforcing phase contained in the latter remains unaffected by the joining process. The test results show neither transport nor mechanical comminution of the silicon carbide particles. It is proven that the quality of the produced material joint as well as the process stability depend on the setting of the variable process parameters. In particular, the ratio between frictional and forge pressure as well as the burn-off length are shown to have a major influence on the joint quality. The intensity of the individual influences is illustrated by the presentation of the parameter main and interaction effects as well as predominant significances. Because the used AMC material is softened by process- and material-related annealing effects, a large proportion of the weld specimens fail outside the joining zone. On the part of the unreinforced aluminum alloy, the absence of such temperature-induced softening is demonstrated. As a consequence, the investigated friction welding process can unusually not be aligned with the lower-strength material.

Analysis of bend angle variation in aluminium – copper friction welding in the presence and absence of nickel interlayer

Friction welding of Aluminium with Copper without interlayer and with Nickel interlayer were performed. Friction welding parameters were Friction pressure, upset pressure and burn-off length. Three levels were chosen for each of these parameters and Taguchi analysis was done, with bend angle as the output parameter. Burn off length followed by friction pressure and upset pressure were found to be the significant parameters for friction welding without interlayer. Friction pressure followed by burn off length and upset pressure were found to be significant parameters for friction welding with Nickel interlayer. The results were analyzed and possible analysis for the results obtained have been given based on friction welding theory.

Experimental investigation on thermoplastic in friction welding

Friction welding (FW) is one of the techniques that join solid-state work pieces by generating heat through mechanical friction. To investigate effects in welding, two different polymers, Nylon − 6 and Delrin (POM), were employed. The welding outputs may be determined by varying the diameter variations between specimens in the range of 5, 4, and 3 mm. The experiment is carried out by changing input parameters including friction pressure, burn-off length, and rotation speed using the trial and error approach.

Microstructural response at the interface and its effect on the fatigue fracture behavior of rotary friction welded dissimilar titanium alloys: Ti–5Al–2Sn–2Zr–4Mo–4Cr (Ti17) and Ti–6Al–2Sn–4Zr–2Mo (Ti6242)

Ti17 and Ti6242 tubes were subjected to rotary friction welding to fully understand the microstructural response and its effect on the fatigue fracture behavior of the dissimilar joint. Experiment was conducted using friction linear speed 1 m s−1, friction pressure 80 MPa, burn-off length 5 mm and forging pressure 120 MPa as welding parameters. Electron backscattered diffraction was utilized to systematically examine the microstructures and microtextures across the Ti17/Ti6242 friction welded interface. Thereafter, two fatigue tests were conducted to characterize the fatigue performance of Ti17/Ti6242 joint, one of which is used to identify the fatigue fracture location of the joint and another one to analyze the fatigue fracture behavior. Results clinched that the formation of joint exhibited 600 μm thick weld interface comprises of thermal-mechanical affected zone (TMAZ), heat affected zone (HAZ) and welding zone (WZ) with varying thicknesses (i.e. 100 μm to 200 μm). It was also observed that Ti17 WZ is occupied by equiaxed β grains (mean size of 10 μm) with only one texture which was closely similar to {110} < 111 >. Whereas, Ti6242 WZ contained acicular α’ laths (1 μm) with two types of α texture. Ti17 HAZ + TMAZ were consisted of acicular α’ laths within refined equiaxed β grains and three types of texture of α and β, were respectively found in Ti17 HAZ + TMAZ zone. Whereas, Ti6242 HAZ + TMAZ zone was developed by elongated equiaxed α, acicular α’ laths and few β phases and only two types of texture of α and one type texture of β were found in this zone. The microstructural response across the joint concentrates plastic deformation in Ti6242 HAZ + TMAZ during fatigue cycle, which causes the fatigue fracture occurs at a radial distance of 150μm from the boundary between the Ti6242 TMAZ + HAZ and Ti6242 base metal.

Pengaruh Double Chamfer terhadap Distribusi Suhu dan Daerah Zpl pada Sambungan Las Gesek AL6061 dengan Simulasi Komputer

Welding is one of the metal joining processes in manufacturing. CDFW (continuous drive friction welding) is a welding process to join two workpieces by applying pressure at one end of the object and rotating another one where the friction action applies at interface. The purpose of this study is to study temperature distribution on the surface of the welding area and the heat-affected zone represented by a fully plasticized zone (Zpl) and to get an insight of a friction welding process. The variables of CDFW used were double chamfer angle, upset pressure, and burn off length. The initial area of friction was equal that is at a diameter of 14 mm. The method of modeling the CDFW friction welding is via computer simulations using ANSYS 18.1 software. This research uses aluminum material type Al6061. The Taguchi method was applied in designing the simulations. In this modeling, the model with the double chamfer of 15 °, the upset pressure of 120 MPa, and the burn-off length of 9 mm has a small ZPl area of 10.256 mm2. Whilst the specimen model, with a double chamfer angle of 45 °, the upset pressure of 240 MPa, and the burn-off length of 7 mm has a large Zpl area of 56.55mm2. The area of a narrow fully plasticized area caused by small chamfer angle and an upset pressure of 240 MPa. The area of fully plasticized zone shows how much material can be integrated during the friction welding process and how much strength of the weld metal. The model with the chamfer angle of 15 º, the upset pressure of 240 MPa, and the burn-off length of 9 mm has the widest temperature distribution and the highest maximum temperature. Meanwhile, the model with the chamfer angle of 30º, the upset pressure of 120 MPa, and the burn-off length of 9 mm has the narrowest temperature distribution and the lowest maximum temperature. The smaller chamfer angle increased upset pressure and burn-off length result in the wider temperature distribution, higher maximum temperature, and smaller Zpl.

Experimental Investigation and Analysis of Tensile Strength of Dissimilar Friction Welded Joints of Aluminium 6061 and Mild Steel

Nowadays, the joining process plays a vital role in every field of engineering application. Various similar and dissimilar materials are joined by many joining processes to a formed complex component. In all joining processes, welding is a very popular and effective joining process that gives permanent joint. In this process material to be joined is under influence of heat which is produced with aid of external (flame) and internal (friction) mediums. Further, there are types of welding process called friction welding which is solid-state welding, in that process friction had developed between materials having relative motion thus sufficient heat also produced, and welding is performed in solid-state. In recent time’s friction welding is widely used in automobile, aeronautical, structural, marine, etc areas due to its flexibility demand for various materials. In this research work, the aluminium 6061 and mild steel are joined by friction welding by varying the rotating speed of lathe chuck, friction time, burn-off length, and the joint is examined by a tensile test to check its strength. Taguchi’s orthogonal array was used to design the experiment and at the end, the ANOVA test is carried out for the optimization of process parameters.

Torsion Strength of Dissimilar Metals Friction Weld Joint of A6061-St41 Round Bar with Various One-Sided Chamfer Angle and Burn-Off Length

Torsion Strength of Dissimilar Metals Friction Weld Joint of A6061-St41 Round Bar with Various One-Sided Chamfer Angle and Burn-Off Length

Simulation of plastic flow driven by periodically alternating pressure and related deformation mechanism in linear friction welding

Comprehensive understandings of plastic flow and microstructure development are vital to control the product performance in friction-based solid-state welding. Presented in this paper is a three-dimensional fully coupled mathematical modeling for plastic flow driven by periodically alternating pressure in linear friction welding. A plastic/plastic friction pair model is proposed to describe the friction interface condition, where the modified Coulomb model is used to calculate the frictional heat. Numerical simulations are well validated by experiments. Results show a significant periodicity in the variation of plastic flow and deformation fields. Two workpieces alignment leads to a periodic extrusion and backflow of materials, which results in a fluctuating increase in the burn-off length. As process reaches the quasi-steady-state stage, compressive deformation plays a predominant role near the interface while shear deformation periodically occurs near the periphery of the interface only as the oscillatory velocity becomes zero. By consideration of plastic flow deformation, the weld microstructure of joint is investigated experimentally. Plastic deformation behavior exhibits high sensitive to welding parameters. Material flow velocity at the interface increases at greater oscillatory parameters owing to higher interfacial temperature, but decreases with increasing friction pressure due to the reduction of interfacial temperature and increment of strain rate.

Genetic algorithm based optimization of friction welding process parameters on AA7075-SiC composite

Friction welded joints of Aluminium metal matrix composite is witnessing tremendous developments in aeronautical and marine applications. The aim of this work is to optimize the process parameters of the rotary friction welding of Al-SiC composite. The aluminium based metal matrix composites containing 10% vol of SiC particles of 20 µm average size was manufactured by stir casting technique. By investigating the mechanical properties such as the micro hardness and tensile strength, the friction welded joints integrity was examined. The friction welding process parameters such as Spindle Speed (SS), Friction Pressure (FP), Upset Pressure (UP) and Burn-Off-Length (BOL) were considered to find their influence on Ultimate Tensile Strength (UTS) and Hardness (HD). Genetic Algorithm (GA) was employed by taking the fitness function as Combined Objective Function (COF) to optimize the friction welding process parameters to predict the maximum value of UTS and HD. Scanning Electron Microscope (SEM) images of the fractured specimen clearly indicated the difference in the failure mode based on the preferred weights combination. The confirmation test also revealed good closeness to the Genetic Algorithm predicted results. The optimised values of process parameters for different weights of UTS and HD had been predicted.

Effect of Burn-off Length on the Properties of Friction Welded Dissimilar Steel Bars

Effect of Burn-off Length on the Properties of Friction Welded Dissimilar Steel Bars

Prediction of Optimized Friction Welding Parameter for Joining of Dissimilar Material using Friction Welding

Abstract Friction welding is widely used to join dissimilar metals and materials. In this study, factorial design of experiments was performed with 3 varying levels of control parameters and 9 experiments to join 304L stainless steel and heat treated EN14 steel. The welding parameters such as friction pressure, upset pressure, burn-off length and rotational speed are considered to determine the effect of tensile strength. As the bond strength varies with different friction welding conditions, tensile strength is evaluated on the weld joint of each specimen. Results revealed that low friction pressure at higher burn off length and high speed results in increased tensile strength. The effect of friction welding parameters is also evaluated in tensile strength for finding the optimal parameter using statistical analysis.

Influence of Friction Pressure at a Given Burn-off Length on the Mechanical and Microstructural Properties of Welded Joints from Medium-Carbon Alloyed Steels in Rotaty Friction Welding

This study investigates the influence of friction pressure at a given burn-off length on the microhardness, tensile properties and microstructure of the welded joints from steel 32-2-Mn and 40-Cr-Ni. Phase transformations occurring in the materials to be welded as a result of thermal deformation effects are analyzed. The change in the length of the thermomechanical affected zone (TMAZ) depending on the friction pressure is shown. The results of the distribution of microhardness in the weld, clearly illustrating the formation of hardened and weakened areas. The results of tensile tests of welded joints are given. Analyzed the place of fracture at various welding parameters. The necessity of studying the distribution of internal residual stresses to explain the mechanism of fracture of welded joints is shown.

Effect of Burn-Off Length for Friction Welded Dissimilar Joints of Inconel 718 and SS410

Effect of Burn-Off Length for Friction Welded Dissimilar Joints of Inconel 718 and SS410

Experimental analysis of mechanical properties of aluminium alloy weldments by friction welding process under cryogenic treatment

ABSTRACTThe present study explores the mechanical and metallurgical properties of friction-welded dissimilar aluminium joints, namely AA6061-T6 and AA7079-T6 which were investigated with the use of a process parameter such as frictional pressure, upset pressure, speed, burn-off length. The parameters are varied according to L9 orthogonal array with three levels. The samples are subjected to non-destructive test to identify the weld integrity without disturbing the component which ensures the weld metals for fitness-for-purpose. Mechanical and metallurgical properties such as tensile strength, hardness and micro structure with 100× and 500× were taken to validate the process. Shallow cryogenic treatment was conducted with different time periods (48 and 72 h). There was no significant improvement rather than reduction in tensile strength for 48 h, but for 72 h, there was an increase in maximum tensile strength of 224 MPa. The welded zone showed complete fusions with some inter metallic phases that are obtained.

Investigation on the Effect of Friction Welding Parameters on Impact Strength in Dissimilar Joints

Due to increase in demand of joining dissimilar material combinations in applications such as cryogenic fluids, power generation industries and reactor cooling systems, the solid state welding is most suitable in the current scenario. In this study, the experiment is undergone to evaluate the impact strength on the friction welded joint of copper and AISI 430 ferritic stainless steel material in the weld interface. The experiment is conducted by varying the input parameters such as friction pressure, upset pressure, burn-off length and rotational speed using Taguchi’s L9 orthogonal array. The welded joints were examined under scanning electron microscopy (SEM) and type of failure mode is discussed.