Effects Of Welding Time Research Articles

Effect of welding time on the joint organization and mechanical properties of 6063 aluminum alloy

The 6063 Aluminum alloy brazing joint was prepared with the Al-Si12 solder. The effect of welding time on the structure and shear properties of brazing weld is studied and the interface is analyzed. The study shows that the spreading performance of brder gradually increases with the welding time, the shear strength of the 6063 aluminum alloy joint increase first and then decreases with the increase of the welding time. When the optimal brazing process is 605°C 15min, the interface between Al-Si12 solder and aluminum alloy is good, and the shear strength is 122.4MPa. To ensure the bonding strength of 6063 aluminum alloy, the optimal insulation time of brazing is 15min.

Effect of welding time on microstructure and properties of Al2O3/AlSiMg/1A95 aluminum alloy direct brazing joint

Al2O3 ceramic and 1A95 aluminum alloy vacuum brazed joints were prepared with Al-Si-Mg-La solder. The effects of brazing time on the structure and shear properties of brazed joints were studied, and the interface of the joints was analyzed. Studies have shown that the shear strength of Al2O3/Ag-Si-Mg-La/Al joints all show a trend of increasing first and then decreasing with the increase of brazing temperature and holding time; when the best brazing process is 590°C×30 min, the boundary between AlSiMgLa solder and aluminum alloy disappears; the interface between Al2O3 ceramic and solder is well bonded, and the shear strength reaches 65.12 MPa. The fracture form of the joint is brittle fracture. Under different brazing process parameters, the fracture position of the joint is mainly divided into two types: when the joint strength is low, the fracture occurs near the interface between the aluminum alloy and the brazing filler metal layer; when the joint strength is higher, the fracture occurs at the interface between the Al2O3 ceramic and the solder.

MULTI-OBJECTIVE OPTIMIZATION OF THE RESISTANCE SPOT-WELDING PROCESS PARAMETERS FOR THE WELDING OF DUAL-PHASE STEEL DP500

Resistance spot welding (RSW) is still the most used form of welding in the automotive industry, primarily for welding steel. One of the advanced steels used in the automotive industry is dual-phase steel, so it is important to properly select the welding parameter for these steels. Therefore, this paper presents multi-objective optimization in the RSW welding process of DP 500 steel. The paper considers three different mechanical characteristics i.e., the failure load (F), failure displacement (l) and weld nugget diameter (D), as all these welding characteristics play significant roles in evaluating the quality of spot welding. The results show that the welding current is the most influential parameter with respect to the mechanical characteristics. The effect of welding time on the weld quality is the least significant. The optimal parameters for welding DP 500 steel obtained in this paper are weld current 8 kA, electrode force 4.91 kN and weld time 400 ms.

Effects of Welding Time and Electrical Power on Thermal Characteristics of Welding Spatter for Fire Risk Analysis

To predict the fire risk of spatter generated during shielded metal arc welding, the thermal characteristics of welding spatter were analyzed according to different welding times and electrical powers supplied to the electrode. An experimental apparatus for controlling the contact angle between the electrode and base metal as well as the feed rate was prepared. Moreover, the correlations among the volume, maximum diameter, scattering velocity, maximum number, and maximum temperature of the welding spatter were derived using welding power from 984–2067 W and welding times of 30 s, 50 s, and 70 s. It was found that the volume, maximum diameter, and maximum number of welding spatters increased proportionally as the welding time and electrical power increased, but the scattering velocity decreased as the particle diameter increased regardless of the welding time and electrical power. When the measured maximum temperature of the welding spatter was compared with an empirical formula, the accuracy of the results was confirmed to be within ±7% of the experimental constant C=112.414×Pe−0.5045. Results of this study indicate quantitatively predicting the thermal characteristics of welding spatter is possible for minimizing the risk of fire spread when the electrode type and welding power is known.

Analysis of Welding Strength S45C Material in Spot Welding Process with Variations in Welding Press Time and Electrode Diameter

Spot welding is one system of connecting to steel materials or other materials that make up sheets. The welding time and electrode diameter are the factors that determine the formation of welding nuggets. This study was conducted to analyze the effect of welding time and electrode diameter on the joint strength of the S45C steel plate with a thickness of 1 mm. The welding process takes place with variations in welding time lasting 1 second, 1.5 seconds, 2 seconds, 2.5 seconds, 3 seconds, and variations in the electrode diameter of 6 mm, 8 mm, 10 mm. The results of welding are then carried out a tensile test to determine the strength of the formed nugget. From the data obtained, an analysis is performed. The highest output voltage analysis result of a 6 mm electrode diameter is 0.92 V with a welding time of 1.5 seconds, 8 mm electrode diameter is 0.9 Volt with 2 seconds welding time and a 10 mm electrode diameter is 0.98 Volt with welding time 1 second. The results of the highest electric power analysis of the 6 mm electrode diameter were 9655.12 Watt with 3 seconds welding time, 8 mm electrode diameter was 9227.66 Watt with 3 seconds welding time, and 10 mm electrode diameter was 9260.64 Watt with 3 seconds welding time. The highest tensile stress analysis results were 20.97 N/mm2 at 6 mm electrode diameter, 21.7825 N/mm2 at 8 mm electrode diameter and 29.555 N mm2 at 10 mm electrode diameter

Rotary Friction Welding of Molybdenum without Upset Forging.

A large instantaneous axial forging load is required to be applied for the final stage of rotary friction welding (RFW), which is usually conducive to obtaining clean, compact, and high-quality joints. However, for slender fuel claddings made of molybdenum (Mo) with low stiffness, the instantaneous axial forging load cannot be applied at the final stage of welding. This study carried out RFW tests without upset forging on Mo in the atmospheric environment and investigated the effects of welding time on joint morphology, axial shortening, microstructures, microhardness, tensile strength, and tensile fracture morphology. It found that the excessive and abrupt burning and a lot of smoke were generated around the weld zone during welding and spiral flashes were observed after welding. Under welding pressure of 80 MPa and spindle speed of 2000 r/min, the minimum average grain size and maximum tensile strength can be obtained in 4 s when the welding time is between 2–5 s. Scanning electron microscope (SEM) results show that there were morphologies of a large number of intergranular fractures and a small number of transgranular fractures in the fracture. The above results demonstrated that it is feasible to use RFW without upset forging to seal the last weld spot on upper end plugs of fuel claddings made of Mo in high-pressure inert gas, which would not only obtain reliable welding quality but also seal high-pressure inert gas in cladding tubes. The research results have a practical guiding significance of manufacturing accident-tolerant Mo nuclear fuel cladding.

Effect of welding time on fatigue properties of friction stir spot welds of Al to carbon fibre-reinforced plastic

ABSTRACTOne way of addressing environmental problems is to increase the use of light-weight materials in automobiles, such as the multi-material structure, which improves fuel economy and reduces pollution. However, it is necessary to develop a welding technique to join carbon fibre-reinforced plastic to metals to achieve a multi-material structure. So, this paper aims to shorten the welding time and to clarify the fatigue fracture mechanism of shear type friction stir spot welding joint between aluminium alloy and CFRP experimentally and analytically. As a result, the static and fatigue strength of the joint improved as the welding time increased due to the increase of total joint area to increased resin melting.

Experimental investigations on resistance spot welding for producing indentation free joints on AISI 409M grade stainless steels

Stainless steels of various grades are widely used in industries including transportation because of high strength and corrosion resistance properties. High initial cost of SS is justified by its increased life and reduced maintenance cost. Effect of welding time and shielding gas on various properties of resistance spot welded joint of AISI 409 M ferritic stainless steel sheets of 2 mm thickness is studied in this paper. The objective of this study is to find the lowest values of parameters that are required to make a joint, which meets the strength requirement with minimum surface indentation levels and discoloration. It is observed that, when weld time is varied, keeping other parameters constant, tensile shear strength found to increase linearly up to certain level and start decreasing thereafter.

Effect of Welding Time on Resistance Spot Weldability of Aluminum 5052 Alloy

In the study, the effect of welding time on resistance spot weldability of aluminum 5052-H32 alloy was analyzed through simulation and experiments. The resistance spot weldability was evaluated by measuring the tensile shear strength, nugget size, and hardness of welds with variations in the welding time. The simulated results of parameters such as tensile shear strength and nugget size obtained using the SORPAS program were compared with the experimental results. Furthermore, a simulation was performed to calculate the temperature inside the weld nugget based on the distance from the center of the nugget. Hence, an optimum welding time to retain the required weld strength of the aluminum 5052-H32 alloy was obtained.

Effect of welding time on microstructure and mechanical properties of Al-Ti ultrasonic spot welds

AA6061 A l alloy and commercial pure Ti sheets were successfully joined by ultrasonic spot welding. The microstructure and mechanical properties of joints under welding time from 0.6 s to 1.4 s were investigated. No intermetallic compounds were founded at the interface of the joints. As the welding time increased, the peak load of the joints firstly increased with the expansion of bond area, then decreased afterwards due to the fatigue crack in Al side. The peak temperature increased with increasing welding time. In the weld region, the aluminum alloy was softened by the weld energy, while the hardness of pure titanium did not change distinctly. All the failure occurred along the interface of the joints with brittle fracture characteristics during tensile shear test.

Identification of the Quality Spot Welding used Non Destructive Test-Ultrasonic Testing: (Effect of Welding Time)

Resistance Spot Welding (RSW) is frequently used as one way of welding is used in the manufacturing process, especially in the automotive industry [4][5][6][7]. Several parameters influence the process of welding points. To determine the quality of a welding job needs to be tested, either by damaging or testing without damage, in this study conducted experimental testing the quality of welding or identify quality of the nugget by using Non-Destructive Test (NDT) –Ultrasonic Testing (UT), in which the identification of the quality of the welding is done with parameter thickness of worksheet after welding using NDT-UT with use same material worksheet and have more thickness of worksheet, the thickness of the worksheet single plate 1mm, with the capability of propagation Ultrasonic Testing (UT) standard limited> 3 mm [1], welding process parameters such as the time difference between 1-10s and the welding current of 8 KV, visually Heat Affected Zone ( HAZ ) have different results due to the length of time of welding. UT uses a probe that is used with a frequency of 4 MHz, diameter 10 mm, range 100 and the couplant used is oil. Identification techniques using drop 6dB, with sound velocity 2267 m / s of Fe, with the result that the effect of the Welding time affect the size of the HAZ, identification with the lowest time 1s show results capable identified joined through NDT - UT.

Development of Resistant Spot Welding Technology for Automotive Ferrite-Martensitic Dual-Phase Steels with Joint Application of Finite Element Modelling and Experimental Research

In this paper spot-welding technology of sheets made of Dual-Phase (DP) steel, which is one of the most important materials in the automotive industry, has been analyzed using finite element modelling and experimental research. The traditional, continuous energy input and the symmetric double pulse as non-continuous energy input were compared for resistance spot welding focusing on the advantages of pulsed energy input. For numerical analysis an axisymmetric coupled finite element model was developed to study the effect of welding time and current intensity on nugget size and thermal history in resistance spot welding process using MSC.Marc software package. The cross-section macrostructures of the welded specimens were examined and compared to the predicted size of the weld nugget and heat affected zone.

Dissimilar ultrasonic spot welding of aerospace aluminum alloy AA2139 to titanium alloy TiAl6V4

The microstructure, hardness, lap shear strength and fracture energy of AA2139–TiAl6V4 spot joints produced by ultrasonic welding were investigated and related to the weld thermal cycle. No obvious intermetallic reaction layer was observed in the AA2139–TiAl6V4 welds, even using transmission electron microscopy. The hardness profile of AA2139 side after welding was studied, demonstrating that the heat introduced by the welding process leads to some softening with partial hardness recovery after natural aging. The effects of welding time on peak load and fracture energy were investigated. The peak load and fracture energy of welds increased with an increase in welding time and then reached a plateau, i.e., maximum peak load 5.3kN and maximum fracture energy 3.7kNmm. In all cases, failure occurred by fracture at the weld interface.

Analytical solution of temperature distribution in resistance spot welding

In this study, an analytical model based on integral transformations was developed to predict nugget diameters in resistance spot welding of 1.5 mm thick 5083-O aluminum alloy sheets. Welding time was fixed at six cycles. However, welding current and electrode pressure were changed; experiments were carried out for both situations. First, the effect of contact resistance on nugget diameters was studied. During the welding process, three electrode forces were selected at 2500, 3000, and 3500 N, and the welding current was fixed at 20 kA. Second, the effect of welding current on the nugget diameter was investigated. In the investigation, the electrode force was fixed at 3000 N, and the welding current was varied at 20, 25, and 30 kA. To improve accuracy, a correction factor to thermal expansion was considered. Finally, the effect of welding time on thermal history was investigated theoretically.

Numerical Simulation of Nugget Geometry and Temperature Distribution in Resistance Spot Welding

Resistance spot welding is an important manufacturing process in the automotive industry for assembling bodies. The quality and strength of the welds and, by extension, the body is mainly defined by the quality of the weld nuggets. The most effective parameters in this process are sheet material, geometry of electrodes, electrode force, current intensity, welding time and sheet thickness. The present research examined the effect of process parameters on nugget formation. A mechanical/ electrical/ thermal coupled model was created in a finite element analysis environment. The effect of welding time and current, electrode force, contact resistivity and sheet thickness was simulated to investigate the effect of these parameters on temperature of the faying surface. The physical properties of the material were defined as nonlinear and temperature dependent. The shape and size of the weld nuggets were computed and compared with experimental results from published articles. The proposed methodology allows prediction of the quality and shape of the weld nuggets as process parameters are varied. It can assist in adjusting welding parameters that eliminates the need for costly experimentation. This process can be economically optimized to manufacture quality automotive bodies.

Effect of Welding Time in the Resistance Spot Welded Dissimilar Stainless Steels

In this study, the effect of welding time on joining capability of austenitic stainless steel (AISI 304) sheets and ferritic stainless steel (AISI 430) sheets by using resistance spot welding (RSW) process was investigated. Therefore, macrostructure, microstructure, microhardness, tensile shear strength, and failure mode of welded materials were determined for various welding times. The welding times values used in the resistance spot welding process were 0.4, 0.8, 1.2, and 1.6 s. Tensile shear tests carried out on the welded joints determined their strength and failure mode. The increase in the welding time resulted in an increase in the nugget size and the weld strength. Two distinct failure modes were observed during the tensile shear test: interfacial, pullout failure modes. Finally, an optimum welding time was obtained.

Microstructural characterization and mechanical properties of high power ultrasonic spot welded aluminum alloy AA6111–TiAl6V4 dissimilar joints

Aluminum alloy AA6111 and TiAl6V4 dissimilar alloys were successfully welded by high power ultrasonic spot welding. No visible intermetallic reaction layer was detected in as-welded AA6111/TiAl6V4 welds, even when transmission electron microscopy was used. The effects of welding time and natural aging on peak load and fracture energy were investigated. The peak load and fracture energy of welds increased with an increase in welding time and then reached a plateau. The lap shear strength (peak load) can reach the same level as that of similar Al–Al joints. After natural aging, the fracture mode of welds transferred from ductile fracture of the softened aluminum to interfacial failure due to the strength recovery of AA6111.

Resistance spot welding and the effects of welding time and current on residual stresses

A 2-D finite element model is developed based on fully coupled electrical-thermal and incrementally coupled thermal-mechanical analysis. The growth rate of the weld nugget as a function of welding time and current is studied. Comparison of the predicted results with the experimental data shows good agreement. Contact area variations and pressure distribution between the sheets’ faying surface and electrode-sheet interfaces during the welding process are studied. Compressive radial residual stress on the surface of the specimen obtained in the center region of the nugget while it becomes tensile and rises toward the nugget edge. The maximum tensile residual stress occurs outside of the nugget, near the edge region. The effects of welding time and current on distribution and magnitude of welding residual stresses are also investigated. The magnitudes of radial residual stresses in the inner and outer areas of the weld nugget grow with increasing the welding time and current while they decrease slightly in the edge regions of the weld nugget. The growth rate of the maximum residual stress reduces with increase in the welding time and current. This fact is more tangible for welding time.

PS16 連続繊維強化熱可塑性樹脂複合材料の超音波溶着における成形条件の影響

Ultrasonic welding was adopted for continuous Fiber Reinforced Thermoplastic composites (c- FRTP) with different thickness, and effect of welding time on the essential welding time, welded area, maximum load and maximum shear stress of lap joint tensile test, were investigated. Essential molding time was increased with increasing in welding time and showed almost the same value regardless of thickness, and maximum load was also increased with an increase in essential molding time. Maximum shear stress was increased with an increase in molding time and then reached to constant value, and thinner specimens showed better maximum stress than thicker one. It might be because of a difference of the energy applied on welding part and interfacial strength leaded by the cooling rate.

Effects of Welding Time and Alloy Elements on Mechanical Properties of Aluminum/SPCC Joint Using Resistance Spot Welding

In this study, effects of welding time and elements Mg, Si and Cu in aluminum alloys on hardness and tensile shear strength of aluminum alloys/steel joints in resistance spot welding have been investigated. The welding current was kept a constant 10.5kA and electrode force was 1kN. Welding time was increased from 0.067s up to 0.2s with a rise of 0.033s. Two intermetallic compound layers were generated at weld interfacial zones between aluminum alloys and steel during welding process, and the major phases were FeAl3 adjacent and directing to aluminum alloy and Fe2Al5 adjacent and directing to the steel. Diffusion of Si in aluminum alloy occurred at the interface, whereas the diffusion of Mg and Cu was not observed at the interface according to the EPMA analysis results. Hardness of intermetallic compound layers was 13.8GPa, which was about 12 times as much as that of the aluminum alloy. The largest tensile-shear strength was obtained on the condition of 0.134 and 0.167s welding time.