Pressure Welding Research Articles

Investigation of the Solid-Phase Joint of VT-14 Titanium Alloy with 12KH18N10T Stainless Steel Obtained by Diffusion Welding through Intermediate Layers

This paper describes the technological process of manufacturing bimetallic billets, which are capable of operating at high pressures, high temperatures, and in corrosive environments, from VT-14 titanium alloy and 12KH18N10T stainless steel. To obtain a joint with a strength of at least 350 MPa, the diffusion welding method was used, which makes it possible to obtain equal-strength joints using dissimilar materials. The connection of VT-14 titanium alloy with 12KH18N10T stainless steel after obtaining bimetallic billets with the desired properties was investigated. We studied the welded VT-14 and 12KH18N10T joint obtained by diffusion welding through intermediate spacers of niobium Nb (NbStrip-1) and copper Cu (M1). On the basis of our investigations, the optimum welding modes are as follows: welding temperature: 1137 K; welding pressure: 18 MPa; welding time: 1200 s. Mechanical tests, tightness tests, and metallographic, factographic, and micro-X-ray structural studies were carried out, the results of which indicate the effectiveness of the proposed approach.

DEVELOPMENT OF TECHNOLOGY AND CREATION OF TEST EQUIPMENT FOR PRESSURE WELDING OF HIGH-LOAD THIN-WALLED HETEROGENEOUS STEEL TUBULAR PARTS

Introduction. Magnetically impelled arc butt welding (MIAB) method differs from the existing arc methods by high productivity, stable quality of welded joints, high degree of mechanization and automation of the technological process and so on. Welding is performed automatically, which significantly reduces the influence of theoperator-welder on the quality of welded joints. The optimal values of the magnetic field induction components for thin-walled tubular parts with a diameter of 212 mm are determined. The basic technological parameters on welding of tubular details in stationary conditions are defined, it is: qualitative preparation of end faces of pipes;optimal distribution of induction of the control magnetic field (CMF); arc voltage; the magnitude and order of programming the welding current; the rate of closure of the arc gap in the process of upset. The influence of liquid metal melt in the arc gap during upset on the formation of welded joints of pipes is determined. Metallographicstudies showed no defects in the weld line and a relatively small area of thermal impact. Mechanical properties of welded joints at the level of mechanical properties of the base metal. Studies have been conducted to determine theparameters that affect the stable movement of the arc along the thin-walled edges of tubular parts and the influence of liquid metal melt in the arc gap during heating on the formation of welded joints.Problem Statement. Pipes of small diameters (up to 220 mm) are used in various industrial enterprises and construction of pipelines. The work requires high-performance automatic welding methods that allow obtaining stable and reliable welded joints.Purpose. The purpose is to raise labor productivity and to save materials by using equipment and technology for press welding of magnetically controlled arc of thin-walled tubular parts.Materials and Methods. Steel thin-walled tubular parts with a diameter of 42mm and 212 mm, with a wall thickness of 2.5… 3 mm were used for research on press welding. To create a control magnetic field, magnetic systems for tubular parts with a diameter of 212 mm were developed. Experimental welding was performed andsamples of welded joints of pipes with a diameter of 212 mm with a wall thickness of 3 mm were investigated. In the course of the research, the main parameters are recorded and the welding process is controlled by computer. Results. The main technological parameters: preparation of pipe ends; magnitude and distribution of control magnetic field induction; the arc voltage; the magnitude and order of programming the welding current; the rateof closure of the arc gap during upset, which affects the formation of welds have been determined. The experimental industrial technology for welding of thin-walled tubular details with a diameter up to 212 mm for thepurpose of its industrial use and the concept of the welding equipment has been developed, patents for the invention have been received.Conclusions. The mechanical and metallographic tests have shown that the properties of welded joints are at the level of the properties of the base metal. The use of press welding technology for tubular parts increases productivity and automates the welding process. The influence of the bandwidth of the liquid molten metal in the arc gap, while heating, on the formation of welded joints of pipes has been experimentally established. The main technological parameters and their influence on the quality of welded joints in the process of heating, the ends, and the upset of thin-walled tubular parts have been determined. Experimental industrial technology for press welding of thin-walled tubular parts has been developed and industrial tests have been conducted, in accordance with the customer's requirements.

Pressure Welding Through a Layer of Hydrocarbon Substance: Physical Processes of a Diffusion Joint Formation

Pressure Welding Through a Layer of Hydrocarbon Substance: Physical Processes of a Diffusion Joint Formation

Multi-Objective Optimization of Resistance Welding Process of GF/PP Composites.

Thermoplastic composites (TPCs) are promising materials for aerospace, transportation, shipbuilding, and civil use owing to their lightweight, rapid prototyping, reprocessing, and environmental recycling advantages. The connection assemblies of TPCs components are crucial to their application; compared with traditional mechanical joints and adhesive connections, fusion connections are more promising, particularly resistance welding. This study aims to investigate the effects of process control parameters, including welding current, time, and pressure, for optimization of resistance welding based on glass fiber-reinforced polypropylene (GF/PP) TPCs and a stainless-steel mesh heating element. A self-designed resistance-welding equipment suitable for the resistance welding process of GF/PP TPCs was manufactured. GF/PP laminates are fabricated using a hot press, and their mechanical properties were evaluated. The resistance distribution of the heating elements was assessed to conform with a normal distribution. Tensile shear experiments were designed and conducted using the Taguchi method to evaluate and predict process factor effects on the lap shear strength (LSS) of GF/PP based on signal-to-noise ratio (S/N) and analysis of variance. The results show that current is the main factor affecting resistance welding quality. The optimal process parameters are a current of 12.5 A, pressure of 2.5 MPa, and time of 540 s. The experimental LSS under the optimized parameters is 12.186 MPa, which has a 6.76% error compared with the result predicted based on the S/N.

Isothermal forming of body cellular panels during upsetting-pressure welding

Relationships for calculating the technological modes of isothermal pressure welding of body cellular panels made of sheet materials are proposed. Cellular panels made of light aluminum and titanium alloys are used in aerospace engineering as load-bearing elements of body structures, wings, fairings, etc. When using such structures as fuel tanks, a reliable joining of elements is required to ensure the tightness of cavities. Compared with traditional methods of welding elements made of materials used in the aerospace industry, pressure welding can significantly reduce the complexity of manufacturing complex structures and improve their quality. Pressure welding of the workpieces included in the assembly is performed under isothermal conditions, i.e., in the solid phase. The main stages of the pressure welding technological process include: upsetting of the workpiece assembly by plastic compression, holding under pressure and relaxation (cooling). Thus, for design and calculation of this process, it is necessary to determine the maximum pressure at a given amount of upsetting, the duration of holding under pressure, and the stress relaxation time in the product material. The determination of the value of upsetting pressure was carried out by the upper-boundary method, using the energy equation of equilibrium during upsetting on the basis of the breaking field of displacement velocities and the equation of creep-plasticity during welding. Depending on the grade of the material and the temperature of forming, an expression is obtained to assess the damageability of the material of the workpieces according to the deformation or energy criteria of destruction. The results of calculating the modes of isothermal pressure welding of a body panel made of aluminum alloy AMg6 at 510 oC are presented and samples of products are shown.The work is conducted within the framework of the graut NSh-2601.2020.8 for state support of the leading RF scientific schools.

Ultrasonic Metal Welding of Multilayered Copper Foils to Nickel-Plated Copper Sheet in Lithium-Ion Battery Cell

The battery performance of electric vehicles depends on the density and capacity of the battery; thus, the battery cells must be assembled in as many layers as possible. Electric vehicle batteries are typically composed of several cells which form modules connected by busbars, with dozens of modules manufactured as battery packs. The ultrasonic metal welding (UMW) technology is applied to such multilayered foil welding. This study analyzed UMW to ensure the weldability of multilayered Cu foils and a Ni-plated Cu strip in lithium-ion battery cells through various approaches. In UMW, the effect of the alignment on weld production and quality were examined through the energy and mechanical performance of the weld by conducting comparative experiments on the alignment of the horn and anvil. Additionally, the effects of UMW process parameters, such as the welding pressure, amplitude, and welding time, were statistically analyzed. The weldability evaluation and characteristic analysis were performed based on these variables. Furthermore, the cross-sectional shapes and microstructure behavior of the Ni layers were analyzed based on the weld quality.

STRUCTURAL THERMAL TRANSIENT NUMERICAL ANALYSIS OF RESIDUAL STRESSES IN CYLINDRICAL PRESSURE VESSELS SUBMITTED TO WELD REPAIR ACCORDING TO STANDARD ASME PCC-2-2015

This paper presents the calculation of residual stresses present in cylindrical pressure vessels subjected to weld repairs using the ASME PCC-2-2015 via numerical multiphysical thermal structural analysis using the finite element method. The methods of analysis of residual stress by numerical analysis are increasingly part of the dynamics of structural integrity in equipment such as pressure vessels, flanges, heat exchangers, in addition to observing the behavior of these stresses in the thermally affected areas due to welding processes. In welding repair, the sleeve is attached to the pressure vessel through two longitudinal welds and two transverse welds. The modeling of the pressure vessel, repair and welding were carried out according to the aforementioned standard. The welding parameters were adopted with what happens in practice, and with that the temperature distribution and heat flow were obtained. The objectives were to analyze the longitudinal, tangential and residual stresses in the regions of the weld, pressure vessel and repair during the welding period, and to verify the behavior of these stresses after the cooling period. This work shows that numerical analysis can be used efficiently and objectively in situations of control and knowledge of the structural integrity of equipment.

Evaluation of Vibration Amplitude Stepping and Welding Performance of 20 kHz and 40 kHz Ultrasonic Power of Metal Welding

Today ultrasonic power technique is consider a mandatory technique which is always entered in many processes such as in metal and plastic welding to overcomes many issues, with aided of applying force (pressure) and supplied high frequency vibration, a solid-state weld can be generated by ultrasonic metal welding technique. That give a technique the ability to join not only a small components, whereas also to join thicker specimens, depend on a proper control of matching welding conditions. Therefore a welding performance can be study and compared after designed welding horn to resonance at frequencies of 20 kHz and 40 kHz. The analyses of the designed horn are completed through use a vibration mathematical expressions, modal and harmonic analyses to ensure the weldability due to applying ultrasonic power to the working area and also to compare the performance of joint at using two resonance frequencies of 20 kHz and 40 kHz. The dimensions of the horns were determined to match the selected resonance frequencies, which the lengths were calculated as 132 mm and 66 mm respectively. The analysis of the exciting modal indicates that the axial vibration modes of 19,584Hz and 39,794Hz are obtained in 10th mode, while the two frequency values are recorded 19,600 Hz and 39,800 Hz from the frequency response of the two horns. The weld strength between Al and Cu specimens with a thickness 0.5 mm were evaluated using tensile test, which the analyses were obtained under using different welding pressure and varied amplitudes. The results were recorded within exciting a horn with two different resonance frequencies, show the enhancement of weld strength and quality through control of stepping amplitude, the enhancement means obtain good strength of the weld, reduce sticking horn to specimen, and lower specimen marking

Evaluation of Vibration Amplitude Stepping and Welding Performance of 20 kHz and 40 kHz Ultrasonic Power of Metal Welding

Today ultrasonic power technique is consider a mandatory technique which is always entered in many processes such as in metal and plastic welding to overcomes many issues, with aided of applying force (pressure) and supplied high frequency vibration, a solid-state weld can be generated by ultrasonic metal welding technique. That give a technique the ability to join not only a small components, whereas also to join thicker specimens, depend on a proper control of matching welding conditions. Therefore a welding performance can be study and compared after designed welding horn to resonance at frequencies of 20 kHz and 40 kHz. The analyses of the designed horn are completed through use a vibration mathematical expressions, modal and harmonic analyses to ensure the weldability due to applying ultrasonic power to the working area and also to compare the performance of joint at using two resonance frequencies of 20 kHz and 40 kHz. The dimensions of the horns were determined to match the selected resonance frequencies, which the lengths were calculated as 132 mm and 66 mm respectively. The analysis of the exciting modal indicates that the axial vibration modes of 19,584Hz and 39,794Hz are obtained in 10th mode, while the two frequency values are recorded 19,600 Hz and 39,800 Hz from the frequency response of the two horns. The weld strength between Al and Cu specimens with a thickness 0.5 mm were evaluated using tensile test, which the analyses were obtained under using different welding pressure and varied amplitudes. The results were recorded within exciting a horn with two different resonance frequencies, show the enhancement of weld strength and quality through control of stepping amplitude, the enhancement means obtain good strength of the weld, reduce sticking horn to specimen, and lower specimen marking.

Pressure welding of corpsl honeycomb panels

ABSTRACT The scheme of pressure welding and the ratio for calculating the technological modes of the manufacturing process of housing cellular panels from sheet materials are proposed. The creep equation is used. The estimation of the damage rate of the workpiece material is given. The calculation results and product samples are presented.

Formability and interface structure of Al/Mg/Al composite sheet rolled by hard-plate rolling (HPR)

How to improve the bonding ability and quality performance of heterogeneous plates has always been one of the difficult problems in the field of high-performance heterogeneous composite sheet forming and manufacturing. In this paper, a new manufacturing method of heterogeneous clad plate, hard plate rolling clad plate, is proposed. The hot rolling process of Al/Mg/Al composite slab with or without hard plate was studied. The results show that the shear stress in the rolling direction (RD) can be transformed into the compressive stress in the normal direction (ND), and then the welding pressure between different composite layers can be increased. This method can suppress the bending and edge crack defects and significantly improve the shape quality and forming ability. At the same time, through the study of the interface structure of the composite plate, it can be known that the metallurgical bonding can be achieved with a small reduction after adding the hard plate. Two clear layers of Al3Mg2 and Al17Mg12 intermetallic compounds appear at the Al/Mg interface. The thickness of the diffusion layer is significantly larger than that of the traditional hot-rolled clad plate, and the thickness of the diffusion layer can reach 38 μm when the reduction is 60%. The yield strength is 172.3 MPa and the elongation is 21.5%. To sum up, the hot rolling of hard-plate provides a new idea for the forming and manufacturing of high performance heterogeneous composite plate.

Sinter-joining of W-10Ti powder to W-10Ti waste target by spark plasma sintering

Spark plasma sintering (SPS) technology has been applied to the sinter-joining of W-10Ti powders and W-10Ti waste targets. The effects of joining temperature (1200–1600 °C) and time (5–20 min) on the microstructure evolution and mechanical properties were studied systematically. The microstructural observation results indicated that the joining temperature and time had a significant effect on the number of βTi(W) phase and grain size. There was little difference in the distribution of relative density and hardness between the powder-sintered body and waste target. The bending strength of the original waste target and regenerated target (1500 °C/5 min) was 660.32 ± 18.94 MPa and 455.30 ± 15.12 MPa, indicating that the powder-sintered body and the waste target achieved a good joining when the temperature was 1500 °C and the time was 5 min. A regenerated W-10Ti target with reliable interface joining, high density, less βTi(W) phase and small grain size was obtained at the joining temperature of 1500 °C and the dwelling time of 5 min. EBSD results at 1500 °C/5 min suggested that the grain boundary diffusion induced the formation of wedge-shaped triple junctions and that a reconstruction behavior occurred at the interface. A schematic diagram was established to characterize the mechanism of the interface formation and evolution. The series of sinter-joining processes assisted by SPS technology are considered to involve pressure welding, micro-arc welding, resistance welding and diffusion welding, which can provide experimental reference and theoretical guidance for repairing the W-10Ti waste target with SPS technology.

Evaluation of Vibration Amplitude Stepping and Welding Performance of 20 kHz and 40 kHz Ultrasonic Power of Metal Welding

Today ultrasonic power technique is consider a mandatory technique which is always entered in many processes such as in metal and plastic welding to overcomes many issues, with aided of applying force (pressure) and supplied high frequency vibration, a solid-state weld can be generated by ultrasonic metal welding technique. That give a technique the ability to join not only a small components, whereas also to join thicker specimens, depend on a proper control of matching welding conditions. Therefore a welding performance can be study and compared after designed welding horn to resonance at frequencies of 20 kHz and 40 kHz. The analyses of the designed horn are completed through use a vibration mathematical expressions, modal and harmonic analyses to ensure the weldability due to applying ultrasonic power to the working area and also to compare the performance of joint at using two resonance frequencies of 20 kHz and 40 kHz. The dimensions of the horns were determined to match the selected resonance frequencies, which the lengths were calculated as 132 mm and 66 mm respectively. The analysis of the exciting modal indicates that the axial vibration modes of 19,584Hz and 39,794Hz are obtained in 10th mode, while the two frequency values are recorded 19,600 Hz and 39,800 Hz from the frequency response of the two horns. The weld strength between Al and Cu specimens with a thickness 0.5 mm were evaluated using tensile test, which the analyses were obtained under using different welding pressure and varied amplitudes. The results were recorded within exciting a horn with two different resonance frequencies, show the enhancement of weld strength and quality through control of stepping amplitude, the enhancement means obtain good strength of the weld, reduce sticking horn to specimen, and lower specimen marking.

Titanium-Alloy Metal Matrix Composites Produced by Low-Temperature Superplastic Pressure Welding

The production of strong metal matrix composites by pressure welding at low temperatures is considered. Failure of the composite is analyzed. It is found that the strength of a composite produced at 700°C may exceed that of a composite produced at 900°C.

Вариационная оценка режима осадки при сварке давлением

There are offered ratios for the computation of deformation and power modes of yielding at billet pressure welding. A power method is used for the computation of pressure with reference to a flat discontinuous field of movement speeds. Pressure minimization is carried out in a variation way. The assessment of billet material damageability is shown.

Pressure Welding of Shells with Creep and Plasticity

An approach to calculating the pressure welding of shells is proposed. Expressions are obtained for states of plasticity, creep, and creep–plasticity in pressure welding.

Hardness distribution and aging response associated with precipitation behavior in a laser pressure welded Al–Li alloy 2198

Abstract Although laser welded Al–Li alloys show great potential for application in aerospace industry, the detailed relationship between local hardness and complex microstructure remained unclear. In the present study, relationship between precipitation behavior and local hardness in a defect-free laser pressure weld of Al–Li alloy 2198 was systematically examined by transmission electron microscopy. Hardness profile of the laser pressure weld was reduced in the vicinity of the weld center, mainly explained by size and density of the strengthening precipitates. Moreover, post-weld aging increased the density of strengthening precipitates in the precipitate-dissolved regions, increasing their hardness values markedly. On the other hand, a few precipitates were formed in the precipitate-coarsened regions during post-weld aging, which slightly increased the local hardness. The variation in hardness during post-weld aging could be well correlated with the precipitation behavior in each region of the laser pressure weld.

The Effect of Chip Binding on the Parameters of the Case-Hardened Layer of Tooth Surfaces for AMS 6308 Steel Gears Processed by Thermochemical Treatment.

The following article describes influence of pressure welded or bound chips to the gear tooth flank and/or the tooth root on a carburized case and surface layer hardness of Pyrowear 53 steel gears, machined by Power Skiving method. This paper is focused only on one factor, the chips generated while forming gear teeth by power skiving, which could result in local changes in the carburized case parameters as a negatively affecting point of mechanical performance of the carburized case. The chips, due to the specifics of the power skiving process and the kinematics of tooth forming, could be subject to the phenomena of pressure welding or binding of chips to the tooth. During the carburizing stage of the downstream manufacturing processes, the chips form a diffusion barrier, which ultimately could result in localized changes in the carburized case. This work was an attempt to answer the question of how and to what extent the chips affect the case hardening. Performed simulations of chips by a generating cupper “spots”, mentioned in the study, represent a new approach in connection with minimization of errors, which could appear during carbon case depth and case hardness analysis for typical chips, generated during the machining process—assurance that a complete chip was bound to the surface. Hardness correlation for zones, where the chip appears with areas free of chips, gives simple techniques for assessment. Performed tests increased the knowledge about the critical size of the chip—1.5 mm, which could affect the case hardening. Obtained experimental test results showed that the appearance of chip phenomena on the gear tooth might have a negative impact on a carburized case depth and hardened layer.

Microstructure and mechanical properties of ultrasonic spot welding TiNi/Ti6Al4V dissimilar materials using pure Al coating

Abstract Ultrasonic spot welding of Ti6Al4V and TiNi shape memory alloy (SMA) dissimilar joints with an Al coating interlayer were investigated. The influence of welding pressures on the macro/microstructures and tensile shear properties were evaluated. The results show that successful joining of Ti6Al4V and TiNi SMA dissimilar materials can be achieved by selecting proper welding pressure. Intermetallic compounds such as Al3Ti were formed in the dissimilar material joints. The tensile shear loads of the joints were increased first then decreased as the welding pressure continually increasing. When the welding pressure and welding time is 0.52 MPa and 0.5 s respectively, the tensile shear load was 931 N. The dissimilar alloy joints failure at the interface of Al coating and TiNi SMA with a brittle fracture mode.

Effect of ultrasonic welding process parameters on hydrostatic pressure resistance of hybrid textiles for weather protection

In the research project presented in this paper, the effects of welding width, pressure force, power, and speed of ultrasonic welding parameters on hydrostatic pressure resistance were examined. A flexible and lightweight PVC-coated hybrid textile material with uniform thickness was used for weather protection purposes. Three main welding parameters at three different levels were selected based on the preliminary test results involving welding widths of 6 and 12 mm. A lapped type of seam was applied for ultrasonic welding and conventional joining techniques. A conventionally sewn zigzag seam was produced using three main factors at two different levels according to the application area. To avoid seam permeability, the conventional seam was sealed with tape by means of hot-air tape welding and subsequently investigated regarding its hydrostatic pressure resistance. The hydrostatic pressure resistance value of the conventional seam was then compared with ultrasonic weld seams of 6 and 12 mm welding width, and its parametric influence on the quality of the seam was analyzed. The result shows that the ultrasonic weld seam with a 12 mm welding width provided a higher hydrostatic pressure resistance than the 6 mm welding width and the conventionally sewn seam. Statistical analyses were also carried out to prove the significant effect of welding process parameters on hydrostatic pressure resistance, whereby the obtained results were statistically significant. A suitable nonlinear numerical model was also developed to predict the hydrostatic pressure resistance.