Prediction of 3-dimensional heat treatment model during the friction stir spot welding of AA 6061

In this research work, a die steel tool was used to join the two aluminium sheets together on a radial drill machine. For this, a cylindrical-shaped tool was fabricated. This tool is then clamped into the drill machine tool post. This rotating tool is then inserted/indented into the workpiece thus generating heat due to friction. The of the deformation of aluminium starts near the vicinity of the die steel tool impression. The tool transferred the soft material from the tip to the plunger. The plunger is in contact with the Aluminum sheet. Soften material is forged on the sheet with the help of a plunger and thus creating a solid phase joint between the Aluminum sheets. Three-dimensional numerical modelings were performed on Ansys software. A 3-D heat transfer model was used to solve the problem of friction stir spot welding (FSSW). This model was solved by applying the energy conservation equation. This model involves the heat generated at the boundary of the workpiece (AA) and the rotating tool and for study, the problem, steady-state heat transfer equation was used. The numerically computed and the measured values are compared to validate the results.

Protection enhancing of threaded connections of light-alloy drill pipes against contact corrosion

When using light-alloy drill pipes (LAIDP) with steel tool joints, the development of contact corrosion is observed under certain operating conditions. The value of corrosion mainly depends on the difference in electrochemical potential (ECP) of the contacting metals. One of the effective methods for increasing the corrosion resistance of aluminum alloys is the micro-arc oxidation (MAO) method. This is an electrochemical process in combination with micro-arc-discharges phenomena at the anode-electrolyte border, which allows forming ceramic coatings of aluminum oxides on the surface, including its high-toughness and wear-resistant phase - α-Al2O3 (corundum). MAO-technology is a highly efficient and environmentally friendly process. At the forming of such a coating on the threaded part and in the tool joint zone of the pipe, a barrier for contact corrosion between the steel tool joint and the surface of the aluminum pipe is created. In this work, contact corrosion on samples in a pair of 1953T1 aluminum alloy - 40KhN2MA steel in a 5% NaCl solution at 80 °C was investigated. The data obtained showed the effectiveness of using protective MAO-coating to reduce contact corrosion and increase the reliability of the tool joint threaded connection of LAIDP.

Optimization of Input Parameters with Carbide Inserts and HSS Tool on CNC Turning of EN19 Steel

This paper deals with the experimental investigation and testing on a single point cutting tool with carbide inserts and high speed steel tool. Cutting tool has to be strong enough to withstand the wear resistance. It is to be proved that carbide inserts have better performance than HSS tools on machining operation. Components with higher surface quality, higher material removal rate in less time and lower tool wear is only possible by carbide insert tools. The tool material selected for this experiment are cemented & tungsten carbide inserts along with high speed steel tool on machining medium carbon steel EN19. The complete machining process is performed on cnc lathe machine Hence the intention of this project is to minimize the surface roughness, tool wear, machining time and increasing the material removal rate. Taguchi’s L9 orthogonal array is favor for this investigation work. The result obtained in this project can be further used for optimizing the process parameters there by optimized results helps the operator to improve the quality as well as production rate.

Characterization of Tool Degradation during Friction Stir Processing of 6061-T6 Aluminum Alloy Extrusions

The diameter of a H13 steel tool with M6 threads and a pin diameter of 5.9 mm and a pin length of 5 mm was measured after each 25.4 mm length of friction stir processing (FSP) of 6061-T6 extrusions. The change in pin diameter with FSP time or distance did not exhibit any steady state and was found to have two distinct regions. Metallographic analysis of two tools subjected to FSP for 60 and 120 seconds showed that (i) threads fractured in early stages of FSP, (ii) a built-up layer formed between the threads, and (iii) threads progressively wore with processing time. The metallographic analysis of an embedded tool showed the presence of a fractured piece of the tool in the stir zone. These points are discussed in detail in the paper.