Extensive work on the influence of pin geometry on

Extensive work on the influence of pin geometry on mechanical properties of 2014 aluminium alloy friction stir welds has been carried out by Zhao et al. [18]. Taper screw thread pin weld was reported to have the highest weld joint efficiency (75%) compared to the threaded cylindrical tool pin profile welds. The tools have all along been designed predominantly by the trial-and-error approach [19]. Most of the previous investigations on the design of tool geometry were focused on optimizing the tool pin profile with respect to microstructure and mechanical properties. However, the study did not provide any clear guidelines for the optimal design of tool geometry. While the effect of different pin profiles has been studied, very little effort has been made to study the influence of tool pin profile on the generation of heat during welding. Several studies concerning the calculation of thermal loading during FSW process are available in literature. Some of these studies [20,21] are based on the critical assumption that cdc42 the heat generated due to pin-material interaction is very low compared to that generated by the shoulder and hence may be neglected. The influence of tool pin profiles on FSW was hardly discussed in the published literature. In many industrial applications steels are readily replaced by nonferrous alloys and aluminium alloys. Some of these materials combine mechanical strength comparable with that of structural steels and low weight. While production of aluminium alloy component is not very complex, joining of these materials can sometimes cause serious problems. The friction stir welding, as a solid state joining technique, can be used to settle the problems appearing in joining of these materials, in which the joined material is plasticized by heat generated by friction between the surface of the plate and the contact surface of a special tool. The tool is composed of two main parts: shoulder and pin. The shoulder is responsible for generating the heat and containing the plasticized material in the weld zone, while the pin mixes the material of the components to be welded, thus creating a joint. This allows for producing defect-free welds characterized by good mechanical properties. However, the material flow behaviour is predominantly influenced by the FSW tool profiles, FSW tool dimensions and FSW process parameters [22]. In order to get the maximum corrosion resistance, FSW process parameters should be optimized. Tool pin profile plays a crucial role in material flow and, in turn, regulates the welding parameters of the FSW process [23]. Friction stir welds are characterized by well defined weld nugget and flow contours, almost spherical in shape, and these contours are dependent on the tool design, the welding parameters and the process conditions [24]. Hence, an attempt has been made to optimize the FSW process parameters to maximize the corrosion resistance of AA2219 aluminium alloy joints using the design of experiment concept, the response surface method and the simulated annealing algorithm.
Experimental details
Optimization of friction stir welding parameters The traditional simulated annealing algorithm method [28] is used as an optimization tool to search the optimum values of the process variables. The mathematical model was framed by using the coded values. Hence, the coded values was optimized and then converted to the actual values. A computer program using MATLAB for the algorithm was developed to optimize the process variables. The objective is first written as a non-linear programming problem, (NLPP).
Result and discussion
Conclusions
Acknowledgements
Historical background and introduction In the modern battles, there is an aim to build a new naval body structures composed of light and strong composite materials [1]. This naval vessel must be able to withstand the damage produced by underwater explosion (UNDEX) Understanding node of Ranvier the interaction between the composite material and the applied load simulate the underwater explosion is an interesting study. Low rates of the stress applied to the composite material were deeply studied in many studies unlike the higher loading caused by the underwater explosion [1].