Multi-Objective Variable Neighborhood Strategy Adaptive Search for Tuning Optimal Parameters of SSM-ADC12 Aluminum Friction Stir Welding

This research presents a novel algorithm for finding the most promising parameters of friction stir welding to maximize the ultimate tensile strength (UTS) and maximum bending strength (MBS) of a butt joint made of the semi-solid material (SSM) ADC12 aluminum. The relevant welding parameters are rotational speed, welding speed, tool tilt, tool pin profile, and rotation. We used the multi-objective variable neighborhood strategy adaptive search (MOVaNSAS) to find the optimal parameters. We employed the D-optimal to find the regression model to predict for both objectives subjected to the given range of parameters. Afterward, we used MOVaNSAS to find the Pareto front of the objective functions, and TOPSIS to find the most promising set of parameters. The computational results show that the UTS and MBS of MOVaNSAS generate a 2.13% to 10.27% better solution than those of the genetic algorithm (GA), differential evolution algorithm (DE), and D-optimal solution. The optimal parameters obtained from MOVaNSAS were a rotation speed of 1469.44 rpm, a welding speed of 80.35 mm/min, a tool tilt of 1.01°, a cylindrical tool pin profile, and a clockwise rotational direction.

Optimisation of FSP process parameters of surface composites using GRA and Taguchi approach

Friction stir processing (FSP) of Al7075-T6 and Boron Carbide(𝐵4𝐶) nanoparticles as reinforcement were performed adopting Taguchi’s 𝐿9 orthogonal array. Optimisation of parameters which are transverse speed (TS), tool rotational speed (TRS), and tool pin profile (TP) based on residual stress and microhardness was done using Taguchi and Grey Relational Analysis (GRA). Result showed that minimum compressive residual stress and maximum microhardness were obtained at TS of 40 mm/min, TRS of 1200 rpm, and square tool pin profile. Analysis of variance showed that TP+TS with 49.63% contribution is the most significant factor to influence residual stress and microhardness.

Variable Neighborhood Strategy Adaptive Search for Optimal Parameters of SSM-ADC12 Aluminum Friction Stir Welding

In this study, we present a new algorithm for finding the optimal friction stir welding parameters to maximize the tensile strength of a butt joint made of the semisolid material (SSM) ADC12 aluminum. The welding parameters were rotational speed, welding speed, tool tilt, tool pin profile, and rotational direction. The method presented is a variable neighborhood strategy adaptive search (VaNSAS) approach. The process of finding the optimal friction stir welding parameters comprises five steps: (1) identifying the type and range of friction stir parameters using a literature survey; (2) performing experiments according to (1); (3) constructing a regression model using the response surface method optimizer (RSM optimizer); (4) using VaNSAS to find the optimal parameters for the model obtained from (3); and (5) confirming the results from (4) using the parameter levels obtained from (4) to perform real experiments. The computational results revealed that the tensile strength generated from VaNSAS was 3.67% higher than the tensile strength obtained from the RSM optimizer parameters. The optimal parameters obtained from VaNSAS were a rotation speed of 2200 rpm, a welding speed of 108.34 mm/min, a tool tilt of 1.23 Deg, a tool pin profile of a hexagon, and a rotational direction of clockwise.

EFFECT OF TOOL PIN PROFILES OVER SQUARE WAVE TOOL PATH PATTERN ON FRICTION STIR WELDING OF AA6061-CU DISSIMILAR ALLOYS

In this present work friction stir welding of Al6061-annealed pure copper dissimilar metals with square wave pattern tool pin movementwas investigated. The aim of this experiment is to identify the significance square wave tool movement on friction stir welding process along with three different tool pin profiles. Different tool pin profiles of square, round and hexaspiral shapes were selected and their significant outcomes were unveiled. Friction stir welding process parameters of 1500 and 2000rpm & tool pin movement step size of 1.0mm and 2.0mm & weaving rate of 100mm/min and 150mm/min were selected. The advantages of tool movement pattern and tool pin profile shape wereexamined by mechanical testing, microstructure analysis. The mechanical results were showed that process parameter of 1500 rpm, 1.0mm step size, weldingrate of 150mm/min and square tool pin profile combination gives better mechanical properties. Micro structural results unveiled achievement of better grain refinement and uniform dispersion of micro constituents by implementation of square wave tool pin movement pattern along with square tool pin profile.The EDAX report confirms that the weld nugget contains both aluminum and copper as equal percentage, which indicates fine mixing of two parent metals.

Effects of friction stir welding on corrosion and mechanical properties of AA6063 in sea water

Submerged friction stir welding (FSW) is used to improve the weld zones mechanical properties in the present study. This research aims to obtain the optimized process parameters used to fabricate the AA6063 Submerged FSW joint. In the Submerged FSW process, the most important influential factors are tool rotational speed, traverse speed, and pin profile in a seawater environment. The different workpieces are friction stir welded while submerged in seawater at different tool rotational speeds, traverse speeds, and tool pin profiles such as square pin, cylindrical taper pin, and threaded pin. The produced weldments were tested for the mechanical properties of higher tensile strength, microhardness, corrosion rate, and the microstructure of weldments was characterized by using a scanning electron microscope, transmission electron microscope, and X-ray diffractometer. The corrosion rate is investigated by using an electrochemical analyzer by potential dynamic polarization open-circuit technique. For this investigation, The Taguchi method with the L9 orthogonal array design of experimentation is adopted. The maximum UTS was acquired in the weld joint fabricated with 1250 r/min of tool rotational speed, 45 mm/min traverse speed, and a square tool pin. The stirred zone is tested for microhardness. High hardness is achieved with high tool rotational speed and low traverse speed with a square tool pin profile. The corrosion rate is also decreased with high tool rotational speed, low traverse speed, and a square tool pin profile.