Investigation of Friction Weldability of En Aw 6063 Aluminium Alloy Tube to Tube Plate Using an External Tool
The traditional welding methods are commonly used tube to tube plate of heat exchangers and economiser. In this study it was investigated that application of an alternative welding method which called friction welding of tube to tube plate by using an external tool was used joining of AlMg0,7Si (EN AW 6063) aluminium alloy. The AlMg0,7Si plates with dimensions 5x50x70 mm were drilled Ø20,5, Ø21, Ø21,5, Ø22 mm. The four different sizes AlMg0,7Si tubes with dimensions 2 mm wall thickness, 20 mm outer diameter, respectively 45,5, 46, 46,5, and 47 mm length friction welded to plate using an external tool (FWTPET) at constant 900 min-1 tool rotational speed. The vertical force between tool shoulder and tube was constant during the welding, and temperature was measured at every different welding parameters. The shear test was done for determining for welded joints using special fixture. Shear strength of welded joints were determined depend on welding parameters
Optimization of friction welding of tube to tube plate using an external tool
The field of materials technology has been witnessing tremendous developments. Friction welding is an important solid state joining technique. In this research study, friction welding of tube to tube plate using an external tool has been performed and the process parameters are optimized by Taguchi L8 orthogonal array. The prioritization of the process parameters has been obtained and ANOVA has been conducted to predict the statistical significance of the process parameters. This is followed by the optimization of welding process parameters using genetic algorithm. The practical feasibility of applying Genetic Algorithm to friction welding process has been ensured by means of studying the deviation between predicted and experimentally obtained welding process parameters.
Phase formation during mechanical alloying in the Ti–Si system
Abstract Mechanical alloying of Ti–Si powder mixture or TiH 1.924 –Si powder mixture was performed by high-energy ball milling, in which the Ti to Si mole ratio was 1:2. The phase formations in both mixtures during milling were investigated by X-ray diffraction. Mechanical alloying a mixture of elemental powders led to the formation of TiSi 2 equilibrium compound, while when starting from Si + TiH 1.924 , a metastable phase was formed. The metastable phase completely transforms to TiSi 2 when the mechanically alloyed powder is annealed at temperatures above 800 °C. Two different pathways of phase transitions during mechanical alloying are attributed to the existence of hydrogen atoms, i.e., when starting from Si + TiH 1.924 compared to Si + Ti, the kinetics for the formation of the TiSi 2 intermetallic compound slows down. The kinetics related to the different phase transitions depending on the starting powder mixture are discussed.