Dissimilar Study on Friction Welding of AA 2025 Tube Plate to Copper Tube Using an External Tool

摘要

In this project the feasibility of friction welding in tube to tube plate using an external tool (FWTPET) of commercial Copper and Aluminum 2025 tube plate is investigated using an clearance fit method and the process parameters have been prioritized using Taguchi's L_(27) orthogonal array. Than experiment is conducted and take results are compressive strength and hardness testing, Radiography test, Scanning Electron Microscopy and Energy Dispersive Spectroscopy testing. Aluminum 2025 are widely used in aerospace, automotive, marine, defense, construction etc. Friction welding is preferred for joining these materials as it is a solid state forge welding process and problems related with welding of aluminum tube plate and copper tube can be subdued through this process. This welding process is a solid state welding procedure that uses a non-consumable rotating tool that is permitted to rub against the work piece hence generating frictional heat. When the weld constraints such as tool rotation speed, welding time, axial load are optimum the friction between the work piece and the tool generates enough heat to create a plastic deformation layer at the weld interface. The process doesn't involve any melting process and whole process occurs in solid state through plastic deformation and mass flow among the work pieces. The experimental investigation of FWTPET is done by varying the friction welding parameters such as work piece rotation speed, depth and projection. The work piece is rotated at the speeds 285 rpm, 480 rpm and 750 rpm, projection 0 mm, 1 mm, 2 mm and depth are 0.5 mm, 1 mm, 1.5 mm. The experiment is done in a general purpose vertical milling machine. To hold the work piece a fixture is designed. A tool is also designed. This work confirms that a high quality tube to tube plate joint can be achieved using FWTPET process.