scholarly journals Effect of shoulder features during friction spot extrusion welding of 2024-T3 to 6061-T6 aluminium alloys

2020 ◽  
Vol 20 (3) ◽  
Author(s):  
Jinzhen Han ◽  
M. Paidar ◽  
R. Vaira Vignesh ◽  
Kush P. Mehta ◽  
A. Heidarzadeh ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Metal Flow ◽  
Base Material ◽  
Welding Process ◽  
Fracture Load ◽  
Stir Zone ◽  
Bottom Surface ◽  
Flow Zone ◽  
Dissimilar Aluminum Alloys ◽  
Extrusion Welding

Abstract Friction spot extrusion welding process is successfully performed on dissimilar aluminum alloys of AA2024-T3 and AA6061-T6 under the influence of shoulder features. The joints were analysed by microstructural features and mechanical properties using conventional and advanced tools of visual inspection, optical microscopy, scanning electron microscopy, transmission electron microscopy, electron back scattered diffractions, tensile testing and hardness testing. The results revealed that the joining was obtained by combination of mechanical locking from extruded material of top surface to predrilled bottom surface and diffusion in solid state. The stir zone and plastically deformed metal flow zone were influenced by scroll shoulder and smooth shoulder features. The tensile specimen of scroll shoulder was resulted to higher fracture load of 6381 N whereas the same was 4916 N in case of smooth shoulder. The interface of between plastically deformed metal flow zone and base material of AA6061-T6 can be considered as critical/weakest zone in case of friction spot extrusion. The variations of hardness were observed in stir zone, plastically deformed metal flow zone and thermo-mechanically affected zone in case of friction spot extrusion welding process.

Mechanical Properties and Corrosion Resistance of Friction Stir Welded Dissimilar Aluminum Alloys 2219 to 5083

2015 ◽  
Vol 813-814 ◽  
pp. 203-207
Author(s):  
M. Koilraj ◽  
A. Sathesh Kumar ◽  
D.L. Belgin Paul ◽  
S.R. Koteswara Rao
Keyword(s):  
Base Material ◽  
Welding Process ◽  
Weld Nugget ◽  
Welding Parameters ◽  
General Corrosion ◽  
Test Results ◽  
Friction Stir ◽  
Dissimilar Aluminum Alloys ◽  
Shoulder Diameter ◽  
Mechanical Properties And Corrosion

In this paper, 6 mm thickness dissimilar aluminium alloys of 5083 (H321) and 2219 (O) butt joints were fabricated successfully by friction stir welding process. The quality joints were obtained for the welding parameters of 35 mm/min and 650 rpm with the shoulder diameter to pin diameter ratio as 3. Macrostructure study shows that the interface between the weld nugget and TMAZ is smooth and clear with a flow arm extending towards the top surface of the weld in the 2219 side. The boundary on the 5083 side between the weld nugget and the TMAZ was irregular. The obtained joint efficiency is around 92.57% based on the UTS of the softer material (AA2219). The tensile test results showed that the specimens failed in the heat affected zone of the softer base material 2219. The hardness values in the stirred zone are higher than the softer base material of alloy 2219. The friction stir welded dissimilar joint 2219-5083 exhibited better general corrosion characteristics than the 2219-2219 weld and 2219 base material.

An investigation into the effect of welding parameters on fatigue crack growth rate and fracture toughness in friction stir welded copper sheets

2015 ◽  
Vol 232 (3) ◽  
pp. 191-203 ◽  
Author(s):  
Ali Alavi Nia ◽  
Ali Shirazi
Keyword(s):  
Fracture Toughness ◽  
Fatigue Crack ◽  
Fatigue Crack Growth ◽  
Crack Growth ◽  
Heat Affected Zone ◽  
Base Material ◽  
Welding Process ◽  
Stir Zone ◽  
Welding Parameters ◽  
Friction Stir

In the present study, the effect of various factors of friction stir welding including rotational and traverse speeds of tool and in fact, the amount of the heat transferred within welding was evaluated on the resistance to fatigue crack growth and fracture toughness in different zones of welding copper sheets. In order to better assess these two properties, other mechanical properties such as tensile strength and hardness were also studied and the microstructure of different zones of welds was investigated using optic and electron microscopies. By doing this study, it became clear that the less the heat transferred to the plunging during the welding process, the better properties the resulting welds will have which well justifies the use of cooling in this study. Transferring heat to plunging causes the growth of grains in various zones and can cause the fatigue crack growth in heat-affected zone to increase averagely about 4.2 times the base material for different Δ K. In contrast, the occurrence of dynamic recrystallization in the stir zone as well as fragmentizing and alignment of grains in this zone can increase the resistance to fatigue crack growth up to 9-fold the resistance of the base material. The other interesting result of this study was that although the properties of stir zone improve by increasing the number of welding passes, the properties of its weakest zone i.e. the heat-affected zone will decline.

Fatigue Behaviour of Friction Stir Welded Steel Joints

2014 ◽  
Vol 891-892 ◽  
pp. 1488-1493 ◽  
Author(s):  
José Azevedo ◽  
Virgínia Infante ◽  
Luisa Quintino ◽  
Jorge dos Santos
Keyword(s):  
Base Material ◽  
Welding Process ◽  
Steel Structures ◽  
Fatigue Behaviour ◽  
Fatigue Tests ◽  
Fatigue Properties ◽  
Welded Steel ◽  
Shipbuilding Industry ◽  
Friction Stir ◽  
Steel Joints

The development and application of friction stir welding (FSW) technology in steel structures in the shipbuilding industry provide an effective tool of achieving superior joint integrity especially where reliability and damage tolerance are of major concerns. Since the shipbuilding components are inevitably subjected to dynamic or cyclic stresses in services, the fatigue properties of the friction stir welded joints must be properly evaluated to ensure the safety and longevity. This research intends to fulfill a clear knowledge gap that exists nowadays and, as such, it is dedicated to the study of welded steel shipbuilding joints in GL-A36 steel, with 4 mm thick. The fatigue resistance of base material and four plates in as-welded condition (using several different parameters, tools and pre-welding conditions) were investigated. The joints culminate globally with defect-free welds, from which tensile, microhardness, and fatigue analyses were performed. The fatigue tests were carried out with a constant amplitude loading, a stress ratio of R=0.1 and frequency between 100 and 120 Hz. The experimental results show the quality of the welding process applied to steel GL-A36 which is reflected in the mechanical properties of joints tested.

Experimental Investigations on Aluminium Ultrasonic Welding Parameters

2014 ◽  
Vol 657 ◽  
pp. 306-310
Author(s):  
Lăcrămioara Apetrei ◽  
Vasile Rață ◽  
Ruxandra Rață ◽  
Elena Raluca Bulai
Keyword(s):  
Microstructural Analysis ◽  
Base Material ◽  
Welding Process ◽  
Ultrasonic Welding ◽  
Experimental Investigations ◽  
Welding Parameters ◽  
Material Structure ◽  
Welding Temperature ◽  
Wide Range ◽  
Made In

Research evolution timely tendencies, in the nonconventional technologies field, are: manufacture conditions optimization and complex equipments design. The increasing of ultrasonic machining use, in various technologies is due to the expanding need of a wide range materials and high quality manufacture standards in many activity fields. This paper present a experimental study made in order to analyze the welded zone material structure and welding quality. The effects of aluminium ultrasonic welding parameters such as relative energy, machining time, amplitude and working force were compared through traction tests values and microstructural analysis. Microhardness tests were, also, made in five different points, two in the base material and three in the welded zone, on each welded aluminium sample. The aluminum welding experiments were made at the National Research and Development Institute for Welding and Material Testing (ISIM) Timişoara. The ultrasonic welding temperature is lower than the aluminium melting temperature, that's so our experiments reveal that the aluminium ultrasonic welding process doesn't determine the appearance of moulding structure. In the joint we have only crystalline grains deformation, phase transformation and aluminium diffusion.

scholarly journals A Study on Determining Weld Joint Hardening and a Quality Evaluation Algorithm for 9% Nickel Weld Joints Using the Dilution Ratio of the Base Material in Fiber Laser Welding

Metals ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1308
Author(s):  
Minho Park ◽  
Jisun Kim ◽  
Changmin Pyo ◽  
Jaewoong Kim ◽  
Kwangsan Chun
Keyword(s):  
Laser Welding ◽  
Fiber Laser ◽  
Weld Joint ◽  
Base Material ◽  
Welding Process ◽  
Fuel Oil ◽  
Welding Quality ◽  
Dilution Ratio ◽  
Fiber Laser Welding ◽  
Evaluation Algorithm

The demand for LNG-powered ships and related equipment is rapidly increasing among major domestic and foreign carriers due to the strengthened IMO regulations on the sulfur content of ship fuel oil. LNG operation in a cryogenic environment requires a storage tank and fuel supply system that uses steel with excellent brittleness and fatigue strength. A ship using LNG is very sensitive to explosion and fire. For this reason, 9% Ni is often used, because ships require high quality products with special materials and structural technologies that ensure operability at cryogenic temperatures. However, research to derive uniform welding quality is urgent because the deterioration of weld quality in the 9% Ni steel welding process is caused by high process difficulty and differences in welding quality depending on a welder’s skill set. This study proposes a method to guarantee a uniform quality of 9% Ni steel in a fiber laser welding process by categorizing weld joint hardness according to the dilution ratio of a base material and establishing a standard for quantitative evaluation.

scholarly journals Research on the Friction Stir Welding of Sc-Modified AA2519 Extrusion

Metals ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 1024 ◽  
Author(s):  
Robert Kosturek ◽  
Lucjan Śnieżek ◽  
Janusz Torzewski ◽  
Marcin Wachowski
Keyword(s):  
Mechanical Properties ◽  
Friction Stir Welding ◽  
Base Material ◽  
Stir Zone ◽  
Welding Parameters ◽  
Friction Stir ◽  
Treated Condition ◽  
Heat Treated ◽  
Heat Treated Condition ◽  
Fsw Parameters

The aim of this research was to investigate the effect of friction stir welding (FSW) parameters on microstructure and mechanical properties of Sc-modified AA2519 extrusion joints. The workpiece was welded by FSW in non-heat-treated condition with seven different sets of welding parameters. For each obtained joint macrostructure and microstructure observations were performed. Mechanical properties of joints were investigated using tensile test together with localization of fracture location. Joint efficiencies were established by comparing measured joints tensile strength to the value for base material. The obtained results show that investigated FSW joints of Sc-modified AA2519 in the non-heat-treated condition have joint efficiency within the range 87–95%. In the joints obtained with the lowest ratio of the tool rotation speed to the tool traverse speed, the occurrence of imperfections (voids) localized in the stir zone was reported. Three selected samples were subjected to further investigations consisting microhardness distribution and scanning electron microscopy fractography analysis. As the result of dynamic recrystallization, the microhardness of the base material value of 86 HV0.1 increased to about 110–125 HV0.1 in the stir zone depending on the used welding parameters. Due to lack of the strengthening phase and low strain hardening of used alloy the lack of a significantly softened zone was reported by both microhardness analysis and investigation of the fractured samples.

scholarly journals A Study on Rotary Friction Welding of Titanium Alloy (Ti6Al4V)

2019 ◽  
Vol 2019 ◽  
pp. 1-9 ◽  
Author(s):  
Ho Thi My Nu ◽  
Truyen The Le ◽  
Luu Phuong Minh ◽  
Nguyen Huu Loc
Keyword(s):  
Mechanical Properties ◽  
Titanium Alloys ◽  
Friction Welding ◽  
Base Material ◽  
Welding Process ◽  
High Strength ◽  
Fusion Welding ◽  
Experimental Results ◽  
Thermomechanical Model ◽  
Rotary Friction Welding

The selection of high-strength titanium alloys has an important role in increasing the performance of aerospace structures. Fabricated structures have a specific role in reducing the cost of these structures. However, conventional fusion welding of high-strength titanium alloys is generally conducive to poor mechanical properties. Friction welding is a potential method for intensifying the mechanical properties of suitable geometry components. In this paper, the rotary friction welding (RFW) method is used to study the feasibility of producing similar metal joints of high-strength titanium alloys. To predict the upset and temperature and identify the safe and suitable range of parameters, a thermomechanical model was developed. The upset predicted by the finite element simulations was compared with the upset obtained by the experimental results. The numerical results are consistent with the experimental results. Particularly, high upset rates due to generated power density and forging pressure overload that occurred during the welding process were investigated. The performances of the welded joints are evaluated by conducting microstructure studies and Vickers hardness at the joints. The titanium rotary friction welds achieve a higher tensile strength than the base material.

Characterization of Local Deformation in Welded Joints Using a Combined Experimental and Numerical Approach

2014 ◽  
Vol 627 ◽  
pp. 241-244 ◽  
Author(s):  
Pawel Kucharczyk ◽  
Sebastian Münstermann
Keyword(s):  
Chemical Composition ◽  
Weld Metal ◽  
Welded Joints ◽  
Base Material ◽  
Welding Process ◽  
Numerical Approach ◽  
Geometrical Model ◽  
Local Deformation ◽  
Heat Treated ◽  
Welded Structure

The microstructure of welded joints differs significantly from that of the base material, what changes their mechanical properties and influences fatigue life. The aim of this work was the investigation of the local deformation field within a butt joint made of 10 mm thick structural steel S355. However, a direct sampling even of the weld metal was impossible due to small dimensions of butt joints. Therefore, the following procedure was utilized in order to manufacture big samples of the microstructure identical to that of the local weldment areas.A geometrical model of the welded structure describing the relevant areas e.g. weld metal, heat-affected zone was established. It was based on the results of the metallographic investigations, hardness mapping and electron-probe-micro-analysis of the local chemical composition. The welding process was numerically simulated using SYSWELD program to estimate the time-temperature-transition (TTT) curves for each identified area. The parameters of the heat input source were calibrated. Afterwards, the material of the defined chemical composition was heat-treated according to the TTT curves. For the validation purpose the heat-treated work pieces were evaluated in terms of microstructure and hardness distribution. Finally, the up-scaled samples of the respective bulk microstructure were manufactured and investigated in monotonic tests.

Development of an Effective ASME IX Welding Procedure Qualification Program for Pipeline Facility and Fabrication Welding

2016 ◽  
Author(s):  
Junfang Lu ◽  
Bob Huntley ◽  
Luke Ludwig
Keyword(s):  
Oil And Gas ◽  
Material Selection ◽  
Base Material ◽  
Welding Process ◽  
Notch Toughness ◽  
Essential Variable ◽  
Performance Qualification ◽  
Pipeline Welding ◽  
Welding Consumable ◽  
Welding Procedure

For cross country pipeline welding in Canada, welding procedures shall be qualified in accordance with the requirements of CSA Z662 Oil and Gas Pipeline Systems. For pipeline facility and fabrication welding on systems designed in accordance with CSA Z662 or ASME B31.4, welding procedures qualified in accordance with the requirements of ASME Boiler & Pressure Vessel Code Section IX are permitted and generally preferred. Welding procedures qualified in accordance with ASME IX provide advantages for pipeline facility and fabrication applications as a result of the flexibility achieved through the larger essential variable ranges. The resulting welding procedures have broader coverage on material thickness, diameter, joint configuration and welding positions. Similarly, ASME IX is more flexible on welder performance qualification requirements and accordingly a welder will have wider range of performance qualifications. When applied correctly, the use of ASME IX welding procedures often means significantly fewer welding procedures and welder performance qualifications are required for a given scope of work. Even though ASME IX qualified welding procedures have been widely used in pipeline facility and fabrication welding, it is not well understood on how to qualify the welding procedures in accordance with ASME IX and meet the additional requirements of the governing code or standard such as CSA Z662 in Canada. One significant consideration is that ASME IX refers to the construction code for the applicability of notch toughness requirements for welding procedure qualification, yet CSA Z662 and ASME B31.4 are both silent on notch toughness requirements for welding procedure qualification. This paper explains one preferred method to establish and develop an effective ASME IX welding procedure qualification program for pipeline facility and fabrication welding while ensuring suitability for use and appropriate notch toughness requirements. The paper discusses topics such as base material selection, welding process, welding consumable consideration and weld test acceptance criteria.

Study of Friction Stir Welding Technics and Weld Performance of Dissimilar 6063-3A21 Aluminum Alloys

2011 ◽  
Vol 299-300 ◽  
pp. 1095-1098 ◽  
Author(s):  
Lei Wang ◽  
Jian Jun Zhu ◽  
Wei Zhang ◽  
Xing Mei Feng ◽  
Zhan Ying Feng
Keyword(s):  
Tensile Strength ◽  
Aluminum Alloys ◽  
Base Material ◽  
Post Weld Heat Treatment ◽  
Weld Strength ◽  
Welding Parameters ◽  
Friction Stir ◽  
Dissimilar Aluminum Alloys ◽  
Performance Results ◽  
Better Than

Several rotating rates and welding speeds were chosen to joint 6063/3A21 dissimilar aluminum alloys, tensile strength of the welds were measured to analyze effect of welding parameters on weld performance. Results show that tensile strength of the weld is better than the base material. Weld tensile strength will decrease under a too high or too low welding speed while effect of rotating rate on weld strength is relatively small. The weakest position is at heat affected zone at 3A21 side after T6 post weld heat treatment.

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