Study of Action Mechanism of Fluxes and Microstructure and Properties of Joints in ZA Alloy TIG Welding
|Course||Materials Processing Engineering|
|Keywords||ZA alloy Welding flux Mechanism of action Organization Performance|
The ZA alloys based on Zn , Al two elements in the main alloying elements such as Cu , Mg, supplemented by the diversified alloy has good mechanical properties , excellent casting properties, good friction and wear characteristics , low cost and low energy consumption , environmental pollution and other characteristics , the increasingly widespread application . The new ZA alloy object of study , a preliminary study of the mechanism of action of ZA alloy TIG welding flux , and the welded joint organization and the performance of the system . The thesis studied the mechanism of action of the the TIG flux in the the ZA alloy welding process . The studies show that the TIG- flux lead to contraction of the plasma arc arc column , so that the conductive channel narrows , the weld width decreases , while the arc voltage increases , the penetration increases ; weld of Zn to reduce the losses . Studies suggest that the flux chemical metallurgical reaction occurs in the welding process : a transition to weld Zn ; two liquid film will be formed in the bath surface , and to protect the molten pool , blocking the evaporation and oxidation of the zinc loss . ZA Alloy Welds slender columnar grain , coarse dendritic and lamellar organizations . Fusion zone organization mainly composed of columnar dendrites , eutectic structure composed . HAZ is composed mainly by the recrystallization zone and the partially recrystallized zone and no coarse overheating organization . ZA alloy TIG weld corrosion resistance is higher than the base material , the tensile strength of the TIG welding head is not less than the base material , and the cleavage site in the base material , the elongation is slightly lower than the base material . Little difference butt welded tensile strength and elongation and base metal , the surfacing joint tensile strength and elongation difference . Weld fusion zone hardness is slightly higher than that of the base material , of which the highest hardness of the fusion zone . ZA alloy welded joint hardness of the fusion zone with the highest value .