Process Evaluation and Numerical Optimization in Friction Stir Welding of Dissimilar AMCs

2022 ◽  
pp. 311-338
Author(s):  
Rajesh P. V. ◽  
Saravanan A.

In recent times, any engineering material is deemed worthwhile only if it satisfies functional characteristics such as weldability, formability, machinability, etc. Aluminum-based metal matrix composites have extensive usage in modern automobile parts, aircraft components, and ship structures, mainly due to their attractive properties such as low cost, high strength-to-weight ratio, excellent corrosion and wear resistance. Friction stir welding is one of the most versatile solid-state joining processes to ensure weldability between two AMC plates. In this research work, an analysis of FSW process through parameters (e.g., composition of alumina, spindle speed, feed, etc.) in joining Alumina reinforced aluminum alloy composites Al 6061 and Al 2024 together at various proportions by analyzing properties like impact strength, hardness, flatness, and ultimate tensile strength has been done. Finally, optimization is carried out to select the best possible combination using a multi-attribute decision-making technique called the complex proportional assessment of alternatives.

Author(s):  
Toshiaki Yasui ◽  
Yuki Ogura ◽  
Xu Huilin ◽  
F. Farrah Najwa ◽  
Daichi Sugimoto ◽  
...  

Abstract For the Friction stir welding (FSW) between aluminum and steel is important to fabricate vehicles with light weight and high strength for safety at low cost. For the fabrication of sound weld, it is necessary to control the material flow during FSW. In this study, the material flow during FSW was elucidated by numerical simulation by computational fluid dynamics (CFD) analysis and simulation experiment by transparent Poly-vinyle chloride (PVC) as simulant of aluminum and tracer material. Based on this material flow analysis, several shapes of welding tool were examined for control of material flow during FSW. Scroll shoulder is effective for enhancement of stirring zone by increasing material velocity around the probe. Flute and fine screw probe promote the material flow in depth and horizontal direction. The welding tool with scroll shoulder and flute and fine screw probe achieved sound weld with highest tensile strength of 120.4 MPa.


2015 ◽  
Vol 787 ◽  
pp. 669-673
Author(s):  
K. Reddi Prasad ◽  
Arumugam Mahamani

Aluminium matrix composites have received the attention of numerous researchers, because of its attractive properties like high strength, good thermal conductivity and more strength to weight ratio. Application of the conventional welding processes for aluminium matrix composites, facilitates the formation of undesirable phase at the welded region, which limits the wide spread application. The objective of this paper is to review the literatures belonging to the friction stir welding of the composites and explore the challenges associated to maximize joint efficiency. The major contribution of this paper is to study the issue of welding of ex-situ and in-situ composites, various process parameters, properties of joint and post weld heat treatment process to improve the joint efficiency. This literature review provides some research gaps in the friction stir welding of composites.


Author(s):  
P. V. Rajesh ◽  
M. Sriram Prasanth ◽  
V. Sam Daniel ◽  
C. M. Saravanan

Aluminium Matrix Composites are extensively used due to their desirable properties like low weight, low cost, high strength to weight ratio, good corrosion resistance, good thermal conductivity and high stiffness. Their applications are diversified in production, thermal, marine and automobile industries. Aluminium is extensively used in ships, aircrafts, cars, electrical wires and household utensils because it is abundant in nature. In the present study, Aluminium alloy Al6061 Hybrid Composites reinforced with Boron carbide and Coconut shell ash are fabricated to replace the individual Aluminium alloy Al6061. For that various tests to determine properties such as strength, hardness, wear and corrosion resistance are conducted on composite samples which make them fit to be used in aircraft window frames by reviewing various literatures. In addition to above, machinability analysis is performed on all the specimens and their surface roughness is measured. Based on the results obtained, we can come to a conclusion that the aluminium composite has superior properties than individual Al6061 alloy.


2019 ◽  
Vol 16 (2) ◽  
pp. 719-724 ◽  
Author(s):  
P. Jayaseelan ◽  
T. V. Christy ◽  
Prabhu G. Rubesh ◽  
R. Srinivasan

Friction Stir welding is a solid state joining process with no filler material. In this work, we specifically investigated the Tool Pin Profile, Tool Material, Base Material and the process parameters in the Aluminum metal matrix composites especially reinforced with Zirconium diboride (Al–ZrB2 . Tools of Various Materials and the corresponding tensile strength of the weld specimen, microstructure analysis and Hardness test are evaluated. Threaded Cylinder made of various materials are OHNS, HCHCr, H13 tools are carried out in the process with D/d Ratio are used. The result will be stated with the Threaded Cylinder pin with which tool material provides highest strength to the Bas material.


2021 ◽  
Author(s):  
Bazani Shaik ◽  
Gosala Harinath Gowd ◽  
Bandaru Durga Prasad

Today is an era of metals including Aluminum alloys owing to a fundamental paradigm shift in research objectives. In addition to superior performance and lightweight criteria that are used to define the innovations of yore, scientists today are compelled to take into consideration the environment-friendliness of the new and novel materials being developed due to the concerns of maintaining a sustainable and safe existence. The solid-state Friction stir welding process has immense potential in the areas of automobiles, aerospace and construction industries due to its overwhelming advantages over the conventional fusion welding process of aluminum alloys. The thesis presents an experimental investigation of friction stir welding of dissimilar aluminum alloys AA7075T651 and AA6082T651. Mathematical modeling equations are developed to predict the tensile strength, impact strength, elongation, and micro-hardness of the dissimilar FSW joints AA7075T651 and AA6082T651. The process parameters are optimized for maximum tensile strength and hardness values. Post weld heat treatment is conducted and the metallurgical properties of the FS welded AA7075T651 and AA6082T651 are presented for different combinations of tool rotational speeds. Aluminum and its alloys are widely used in nonferrous alloys for many industrial applications. Aluminum exhibits a combination of an excellent mechanical strength with lightweight and thus it is steadily replacing steel in industrial applications where the strength to weight ratio plays a significant role. In conventional welding, the joining of aluminum is mainly associated with a high coefficient of thermal expansion, solidification shrinkage and dissolution of harmful gases in the molten metal during welding. The weld joints are also associated with segregation of secondary alloys and porosities which are detrimental to the joint qualities. Friction Stir Welding (FSW) and Friction Welding (FW) are the most popular emerging solid welding techniques in aircraft and shipbuilding industries. FSW is mainly used for the joining of metal plates and FW is mainly used for the joining of rods. Both techniques are suitable for high strength material having less weight. These techniques are environmentally friendly and easy to execute. Hence, the study of these techniques can contribute much to the field of green technology. This research work is dealt with the experimental and numerical investigations on FSW and FW of aluminum alloys.


2012 ◽  
Vol 622-623 ◽  
pp. 330-334 ◽  
Author(s):  
G. Elatharasan ◽  
V.S. Senthil Kumar

The heat treatable aluminium alloy AA7075 is used extensively in the aircraft industry because of its high strength to weight ratio and good ductility. In this present study the effect of process parameters on the mechanical and micro-structural properties of AA 7075 joints produced by friction stir welding was analyzed. The two sheets, aligned with perpendicular rolling directions, have been welded successively. The welded sheets have been tested under tension at room temperature in order to analyze the mechanical response with respect to the parent materials. Effects of welding speed and fixed location of base metals on microstructures, hardness distributions, and tensile properties of the welded joints were investigated. Optical microscope and SEM analysis revealed that the stir zone contains a mixed structure and onion ring pattern with a periodic change of grain size as well as a heterogeneous distribution of alloying elements. The maximum tensile strength was achieved for the joint produced at rotation speed of 800rpm and a welding speed of 20 mm/s.


2016 ◽  
Vol 710 ◽  
pp. 41-46 ◽  
Author(s):  
Aline F.S. Bugarin ◽  
Fernanda Martins Queiroz ◽  
Maysa Terada ◽  
Hercílio G. De Melo ◽  
Isolda Costa

2XXX and 7XXX high strength aluminum alloys are the most used materials for structural parts of aircrafts due to their high strength/weight ratio. Their joining procedure is an engineering challenge since they present low weldability. Friction Stir Welding (FSW) is a joining technology developed in the early 90 ́s. It is a solid-state welding process, without the use of fillers or gas shield, that eliminates conventional welding defects and has been considered of great interest for application in the aircraft industry. FSW of aluminum alloys results in four regions of different microstructures, specifically: the base material (BM), the heat affected zone (HAZ), the thermo-mechanically affected zone (TMAZ), and the nugget zone (NZ). The complex microstructure of the weld region leads to higher susceptibility to localized corrosion as compared to the BM even when similar alloys are joined. The welding of dissimilar alloys in its turn results in even more complex microstructures as materials with intrinsically different composition, microstructures and electrochemical properties are put in close contact. Despite the great interest in FSW, up to now, only few corrosion studies have been carried out for characterization of the corrosion resistance of dissimilar Al alloys welded by FSW. The aim of this study is to investigate the corrosion behavior of aluminum alloy 2024-T3 (AA2024-T3) welded to aluminum alloy 7475-T761 (AA7475-T761) by FSW. The evaluation was performed in 0.01 mol.L-1 by means of open circuit potential measurements, polarization techniques and surface observation after corrosion tests.


2016 ◽  
Vol 704 ◽  
pp. 85-93 ◽  
Author(s):  
Isabel Montealegre-Meléndez ◽  
Erich Neubauer ◽  
Cristina Arévalo ◽  
Ana Rovira ◽  
Michael Kitzmantel

Nowadays, the demands for materials with high strength based on a titanium matrix are increasing. The manufacturing of titanium composites through low cost and near-net-shape techniques is a challenge for the industry. There are different processing routes to meet these requirements of the market. As it is well known fast powder metallurgical densification techniques could satisfy these needs. In the present work, several titanium metal matrix composites (TiMMCs) have been fabricated by using a fast hot consolidation technique, namely direct hot pressing (dHP) in order to reduce the manufacturing time. Through a pressure assisted sintering with direct heating of a pressing die the consolidated composites can be formed directly from powders in a short period of time (15 min). The matrix materials were selected from two titanium grade 1 powders and as reinforcement materials boron carbide and boron amorphous particles were employed. Varying the reinforcement’s content in addition to their particle size, their influence on the composites behaviour was expected. Furthermore in this research work, the mechanical and microstructural characterisation of the specimens was carried out in order to identify the best combination of process parameters, material reinforcement and matrix powders.Nowadays, the demands for materials with high strength based on a titanium matrix are increasing. The manufacturing of titanium composites through low cost and near-net-shape techniques is a challenge for the industry. There are different processing routes to meet these requirements of the market. As it is well known fast powder metallurgical densification techniques could satisfy these needs. In the present work, several titanium metal matrix composites (TiMMCs) have been fabricated by using a fast hot consolidation technique, namely direct hot pressing (dHP) in order to reduce the manufacturing time. Through a pressure assisted sintering with direct heating of a pressing die the consolidated composites can be formed directly from powders in a short period of time (15 min). The matrix materials were selected from two titanium grade 1 powders and as reinforcement materials boron carbide and boron amorphous particles were employed. Varying the reinforcement’s content in addition to their particle size, their influence on the composites behaviour was expected. Furthermore in this research work, the mechanical and microstructural characterisation of the specimens was carried out in order to identify the best combination of process parameters, material reinforcement and matrix powders.


Author(s):  
Kulwant Singh ◽  
Gurbhinder Singh ◽  
Harmeet Singh

The weight reduction concept is most effective to reduce the emissions of greenhouse gases from vehicles, which also improves fuel efficiency. Amongst lightweight materials, magnesium alloys are attractive to the automotive sector as a structural material. Welding feasibility of magnesium alloys acts as an influential role in its usage for lightweight prospects. Friction stir welding (FSW) is an appropriate technique as compared to other welding techniques to join magnesium alloys. Field of friction stir welding is emerging in the current scenario. The friction stir welding technique has been selected to weld AZ91 magnesium alloys in the current research work. The microstructure and mechanical characteristics of the produced FSW butt joints have been investigated. Further, the influence of post welding heat treatment (at 260 °C for 1 h) on these properties has also been examined. Post welding heat treatment (PWHT) resulted in the improvement of the grain structure of weld zones which affected the mechanical performance of the joints. After heat treatment, the tensile strength and elongation of the joint increased by 12.6 % and 31.9 % respectively. It is proven that after PWHT, the microhardness of the stir zone reduced and a comparatively smoothened microhardness profile of the FSW joint obtained. No considerable variation in the location of the tensile fracture was witnessed after PWHT. The results show that the impact toughness of the weld joints further decreases after post welding heat treatment.


2021 ◽  
Vol 13 (4) ◽  
pp. 168781402110090
Author(s):  
Sudip Banerjee ◽  
Prasanta Sahoo ◽  
J Paulo Davim

Magnesium matrix nanocomposites (Mg-MNCs) are high grade materials widely used in aerospace, electronics, biomedical and automotive sectors for high strength to weight ratio, excellent sustainability and superior mechanical and tribological characteristics. Basic properties of Mg-MNCs rely on type and amount of reinforcement and fabrication process. Current study reviews existing literatures to explore contribution of different parameters on tribological properties of Mg-MNCs. Effects of particle size and amount of different reinforcements like SiC, WC, Al2O3, TiB2, CNT, graphene nano platelets (GNP), graphite on tribological behaviour are discussed. Incorporation of nanoparticles generally enhances properties. Role of different fabrication processes like stir casting (SC), ultrasonic treatment casting (UST), disintegrated melt deposition (DMD), friction stir processing (FSP) on wear and friction behaviour of Mg-MNCs is also reviewed. Contributions of different tribological process parameters (sliding speed, load and sliding distance) on wear, friction and wear mechanism are also examined.


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