Plasma Arc Welding Technology Design And Micro Structure Analysis Of Zamak3 Zinc Alloy

Zinc alloy is widely used in hoisting machinery,household goods,etc.due to its good workability,corrosion resistance and many other excellent properties,but how to connect zinc alloy efficiently and economically limits its application in some fields.Fusion welding High speed and low cost,but due to the problems of pores,evaporation and oxide film in zinc alloy melting welding,its welding effect is not good.This article uses the principle of non-transferred arc plasma arc welding to make a welding gun,and improves the welding process and parameters.As well as the analysis of the structure and performance,a better welded joint has been obtained,and the forming performance is superior,which provides a new idea for the development of fusion welding of zinc alloy,which has strong practical significance and research significance.This article uses Marc software to simulate the welding temperature field and stress field.According to the results,the process method and parameters of the subsequent tests are guided,and a plasma arc welding gun is built.A series of process tests are performed on Zamak3 zinc alloy,and the welding current and welding speed are analyzed.,The relationship between the shielding gas flow rate and the welding seam formation has obtained relatively good welding parameters.The influence of the solute composition in TM51-F and self-made ZnCl₂ flux on the welding process,as well as the correlation with the welding seam formation,penetration and composition,are studied.Character,which determines the metallurgical reaction process.The mechanism analysis of the structure,hardness,tensile strength,composition,corrosion resistance,and pores of the welded joints:the center of the weld is dominated by dendritic and equiaxed crystals,and the heat-affected zone is mostly columnar crystals,which is different from undercooling.The degree of temperature is closely related to the change of temperature gradient;the hardness of the fusion zone>the center of the weld>the base material,which is related to the grain refinement of the weld,and the Zn-Al solid solution generated in the heat-affected zone decomposes and relieves the indentation when pressed,but the three are relatively different Smaller,less impact on performance;due to the finer structure of the weld,the relative content of Al element is higher,and the tensile strength is improved;the flux removal oxide reaction residue covers the molten pool and reduces the heat input while reducing the evaporation of Zn.ZnCl₂Supplementing Zn to the weld effectively reduces the burning loss of Zn and makes the Zn content less than 5%of the base metal.The acid corrosion resistance of the weld has no significant change relative to the base metal,but the salt corrosion resistance is greatly increased.The corrosion weight loss coefficient K is significantly reduced,which is related to the fact that Zamak3 is not easy to react with salt,the relative content of Al element increases,and the decrease of pores reduces the contact area;the number of pores in the weld is reduced compared to the base metal,but the area increases,mainly due to The stirring and remelting of the molten pool by the plasma gas and the change of the temperature coefficient of the solubility of the active elements on the gas make the bubbles continue to gather and grow and finally escape.A small number of large bubbles will escape into pores in the future,but they are all in the micron size.The performance impact is small and can satisfy the use..