Effect of pulsed current on the mechanical property of weldment of Pure (AA1900) Aluminium

Pulsed Gas Tungusten Arc Welding (GTAW-P) combines the low spatter level of spray transfer with the low heat input of globuler and short circuit transfer. The main drawback of GTAW-P is the large number of paraxmeter s that must be adjusted to produce a stable arc. Synergic control with programmed ability has made the application of complicated pulse wave-forms simple and easier. These all characteristics are very suitable for the welding of pure aluminium (99.95% purity) because the refractory oxide film which is difficult to avoid insoluble in the metal and infers with the wetting action of molten filler metals. GTAW-P power source can remove these difficulties by selecting suitable high peak current and low background current. Here high peak current timing indicates the melting time of the electrode and background current time indicates the heat dissipation and solidification time. So, this concentrated heat input can burn the oxide layer and remove the difficulties produced by it. This also indicates the easiness of welding in upward position, with uneven root gap and also for low thickness we don’t have the problem like burn through. The effect of the pulsed parameters on the weldment shall be evaluated by taking peak current, background current, frequency and pulse ratio as variable parameters and rest are taken as constant. Total 26 readings will be taken and on the basis of this the mechanical properties will be found out .Now on the basis of this results optimized parameter will be concluded by Taghuchi method that will be incorporated by MINITAB software and will be proven experimentally Finally the superiority of pulsed welding will be proven by taking the readings for the same welding condition but under the continuous welding.