International Journal of Innovative Technology and Exploring Engineering (IJITEE) ISSN: 2278-3075, Volume-8 Issue-7, May, 2019 2077 Published By: Blue Eyes Intelligence Engineering & Sciences Publication Retrieval Number G5554058719/19©BEIESP Influence of Tool Geometry and Effects of Plunge Depth in Friction Stir Welding Of AA2014 Borigorla Venu, L.S. Raju Abstract Friction stir welding (FSW) is a noteworthy technique this is used to fabricate the joints which are difficult to join by fusion welding methods and it gives fabulous results compare to Conventional Welding. In FSW process parameters such as Tool Rotation speed, Traverse speed, Axial Force, Plunge Depth and Tilt angle and tool geometry plays a vital role to obtain the defect free welds, towards this achievement the tool shape, especially the shoulder and pin structure design plays a crucial role. In this paper, equations are made using the MATLAB to find out the geometry of the shoulder and pin changes based on the thickness of the welding plate. This makes it possible to produce specific tool dimensions, by using these equations, a tool was developed. Similarly, the experiments were conducted by varying the plunge depth and correlated the results of microstructure, mechanical properties and fracture features. Key words:Tool Design; Plunge Depth; Defects; MATLAB, properties. I. Introduction Present century, the field of manufacturing concentrated towards the safety, life, quality and cost of the product for better achievements a numerous techniques i.e. friction stir welding was invented by the welding Institute (TWI) in 1991 [6].Friction stirring is a surname of the Friction stir welding and processing (FSW&P).Presently, this technique gives worthy consequences compare to other existing techniques in welding, where the tool Plays a key role in the process of joining [1]. The tool comprises pin and shoulder. The pin generates the frictional and deformational heating makes the material soften, and the shoulder generates the heat in between the work-piece and contact area of shoulder, expands the region of softened material,and constraints thedeformed material[2].The tool life is dependent on the selection of tool material and its geometry were the pin and shoulder material is same otherwise the tool does not have the significant effect in FSW&P [3]. Plasticized material gets translated in the weld route, and is moved from the leading edge of tool to the trailing edge, where it is forged into the joint and thus creates a through solid phase bonding between the plates [4]. Joint strength is dependent on the geometry of tool such as shoulder length, shoulder diameter, pin height, pin diameter [5]. In the past decades many researches dedicated on the effect of tool pin profiles and plunge depth on the mechanical and microstructures of Friction stir welding joints of several aluminium alloys. Revised Manuscript Received on May 06, 2019 Borigorla Venu, Mechanical, Engineering, VFSTR, Guntur, India. L.S.Raju, Mechanical Engineering, VFSTR, Guntur, India. Very little amount work was carried out on AA2014- T651.The coreidea of this study is to focus on the influence of tool design and various plunge depth with constant welding speed and tool rotational speed on AA2014-T651 weldments.The representation diagram of the FSW as presented in the Fig.1. Fig.1 schematic diagram of FSW II. EXPERIMENTAL PROCEDURE The experimental work has been carried out on AA2014- T651of 5.5 mm thick sheet and the experimentation was comprises in to two parts like design and fabrication. The tool design was done by using MATLAB and Fabrication was done by using the Computer Numerical Control FSW (CNCFSW).H13 tool steel was chosen as a tool material due their strength, less wear resistance and thermal fatigue behaviour. The piloted experiments were using taper threaded cylindrical tool pin profile on CNCFSW of AA2014 by varying the plunge depth were tool rotation speed and welding speed are constant like 900rpm and 60mm/min. The fabricated joints were shown in Figure 3. The tool dimensions were calculated by using the MATLAB software, the coding details are presented in results phase. A. Metallographic testing: The sample specimens for microstructure investigation were prepared to the requisitesizes from Friction Stir Joints towards perpendicular to welddirection, and then polished the specimens with different grades of emery papers, finally etched by using Keller’s reagent. Samples microstructures of the weld region is examined with optical microscope. B. Mechanical Testing: Specimens for tensile test were sliced based on ASTM E8M in the perpendicular direction of the weld joints. Tensile test is carried out by using the computerized universal Testing Machine. Impact test specimens were sliced perpendicular direction of the weld line with ASTM A370 standards. The hardness samples also prepared in a same manner. The microhardness was measured at the weldzone by the help of vicker’s hardness tester with a 100grams load and dwell time of 10 seconds.