Multi Response DEA-Based Taguchi Optimization of Process Parameters on AA8011 Friction Stir Welded Aluminium Alloys

2015 ◽  
Vol 766-767 ◽  
pp. 921-927 ◽  
Author(s):  
K. Palani ◽  
C. Elanchezhian ◽  
G.B. Bhaskar

In this investigation, an attempt using data envelopment analysis based Taguchi method, is involved in solving the multi-response optimization of the process parameters of rotational speed, transverse speed, tool tilt angle with different tool pin profiles on the stir zone evolution in AA8011 Aluminium alloys. Three different tool pin profiles (hexagonal, pentagonal pin profiles of High Carbon High Chromium steel and Hexagonal tool pin profile of H13 steel) have been used to make the joints at the different combination of process parameters using L9 orthogonal array. The Vickers hardness and Impact strength are measured to optimize the process parameters using DEA based Taguchi method. It is found that the optimum conditions of rotational speed 660 RPM, transverse speed of 30 mm per minute and tilt angle of 2 degrees with the hexagonal tool pin profile of High Carbon High Chromium steel yielded a good quality weld.

2014 ◽  
Vol 695 ◽  
pp. 20-23
Author(s):  
L.H. Shah ◽  
N.F. Zainal Ariffin ◽  
Akhtar Razul Razali

In this study, the Taguchi method was utilized to determine the optimum process parameters for dissimilar friction stir welding between AA6061 and AA7075 aluminium alloys. The Taguchi L9 orthogonal array and optimization approach was applied on three levels of three critical factors, namely rotational speed, transverse speed and tool tilt angle. The optimum levels of process parameters were determined through the Taguchi parametric design approach. Through the parameter analysis, the predicted value of the dissimilar joint’s tensile strength was calculated to be 209.7 MPa, which is in close proximity to the experimental data (219.6 MPa) with 4.5% error. It can be concluded that a high tensile value of 219.6 MPa was achieved using 1000 rpm rotational speed, 110 mm/min travel speed and 3 ̊ tilt angle.


Author(s):  
Sanjay Kumar ◽  
Sudhir Kumar ◽  
Ajay Kumar

The friction stir welding is a pioneering solid-state metal joining technique for producing high-quality joints in materials. In this article, Taguchi approach is applied to analyze the optimal process parameters for optimum tensile strength and hardness of welded dissimilar A6061 and A6082 alloys. An orthogonal array of L9 is implemented and the analysis of variance is employed to investigate the importance of parameters on responses. The experimental tests, conducted according to combination of rotational speed, tool tilt and types of tool pin profile parameters. The results indicate that the rotational speed is most significant process parameter that has the highest influence on tensile strength and hardness, followed by tool pin profile and tool tilt. The optimum results verified by conducting confirmation experiments. The predicted optimal value of tensile strength and hardness of dissimilar joints produced by friction stir welding are 267.74 MPa and 80.55 HRB, respectively.


2015 ◽  
Vol 813-814 ◽  
pp. 446-450 ◽  
Author(s):  
K. Palani ◽  
C. Elanchezhian

The friction stir welding process is the newly developed material joining process used to join the different materials which are very difficult to join in the conventional fusion welding process. In this investigation using the specially designed straight cam profiled tool, the multiple responses of Ultimate tensile strength, Ultimate yield strength and Percentage of elongation with the process parameters of rotational speed, tool tilt angle and feed rate are optimized. The five level, three factor rotatable central composite design is selected to optimize the responses of friction stir welded AA 8011 aluminium alloys. The highest gray relational grade with the highest relative efficiency is found using the gray relational analysis coupled with the data envelopment analysis to predict the optimum parameters. It exposes that at the rotational speed of 680 rpm, the tool tilt angle of 98 degrees and the feed rate of 24 mm/min the good weld quality can be attained.


Alloy Digest ◽  
1969 ◽  
Vol 18 (4) ◽  

Abstract AISI Type 440B is a hardenable high-carbon high-chromium steel recommended stainless for cutlery, valve parts, ball bearings, pivot pins, etc. This datasheet provides information on composition, physical properties, microstructure, hardness, elasticity, and tensile properties as well as fracture toughness. It also includes information on corrosion resistance as well as forming, heat treating, machining, joining, and surface treatment. Filing Code: SS-223. Producer or source: Stainless steel mills.


Materials ◽  
2021 ◽  
Vol 14 (16) ◽  
pp. 4375
Author(s):  
David G. Andrade ◽  
Sree Sabari ◽  
Carlos Leitão ◽  
Dulce M. Rodrigues

Friction Stir Spot Welding (FSSW) is assumed as an environment-friendly technique, suitable for the spot welding of several materials. Nevertheless, it is consensual that the temperature control during the process is not feasible, since the exact heat generation mechanisms are still unknown. In current work, the heat generation in FSSW of aluminium alloys, was assessed by producing bead-on-plate spot welds using pinless tools. Coated and uncoated tools, with varied diameters and rotational speeds, were tested. Heat treatable (AA2017, AA6082 and AA7075) and non-heat treatable (AA5083) aluminium alloys were welded to assess any possible influence of the base material properties on heat generation. A parametric analysis enabled to establish a relationship between the process parameters and the heat generation. It was found that for rotational speeds higher than 600 rpm, the main process parameter governing the heat generation is the tool diameter. For each tool diameter, a threshold in the welding temperature was identified, which is independent of the rotational speed and of the aluminium alloy being welded. It is demonstrated that, for aluminium alloys, the temperature in FSSW may be controlled using a suitable combination of rotational speed and tool dimensions. The temperature evolution with process parameters was modelled and the model predictions were found to fit satisfactorily the experimental results.


Author(s):  
Shubham Verma ◽  
Joy Prakash Misra ◽  
Meenu Gupta

The present study deals with the application of sequential procedure (i.e. steepest ascent) to obtain the optimum values of process parameters for conducting friction stir welding (FSW) experiments. A vertical milling machine is modified by fabricating fixture and tool ( H13 material) for performing FSW operation to join AA7039 plates. The steepest ascent technique is employed to design the experiments at different rotational speed, welding speed, and tilt angle. The ultimate tensile strength is considered as a performance characteristic for deciding the optimal levels. The mechanical and metallurgical characteristics of the joints are studied by executing tensile and microhardness tests. It is concluded from the graphical analysis of the steepest ascent technique that the optimal maximum and minimum values are 1812–1325 r/min for rotational speed, 43–26 mm/min for welding speed, and 2°–1.3° for tilt angle, respectively. Besides, optical microscope and scanning electron microscope are utilized for microstructural and fractographic analyses for a better understanding of the process.


Author(s):  
Sanjeev Verma ◽  
Vinod Kumar

Aluminium and its alloys are lightweight, corrosion-resistant, affordable and high-strength material and find wide applications in shipbuilding, automotive, constructions, aerospace and other industrial sectors. In applications like aerospace, marine and automotive industries, there is a need to join components made of different aluminium alloys, viz. AA6061 and AA5083. In this study friction stir welding (FSW) is used to join dissimilar plates made of AA6061-T6 and AA5083-O. The effect of varying tool pin profile, tool rotation speed, tool feed rate and tilt angle of the tool has been investigated on the tensile strength and percentage elongation of the welded joints. Box-Behkan design, with four input parameters and three levels of each parameter has been employed to decide the set of experimental runs. The regression models have been developed to investigate the influence of welding variables on the tensile strength and elongation of the welded joint. It is revealed that with the increase in welding parameters like tool rpm, tool feed rate and tilt angle of the tool, both the mechanical properties increase, reach a maximum level, followed by a decrease with further increase in the value of parameters. Amongst different types of tool pin profiles used, the FSW tool having straight cylindrical (SC) pin profile is found to yield the maximum strength and elongation of the welded joint for different combinations of welding parameters. Multiple response optimization indicates that the maximum UTS (135.83 MPa) and TE (4.35%) are obtained for the welded joint fabricated using FSW tool having SC pin profile, tilted at 1.11° and operating at tool speed and feed rate of 1568 rpm and 39.53 mm/min., respectively.


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