Effects Of Zr Elements On Microstructure And Properties Of ZA35 Alloy

As one main kind of structural materials ZA alloy is widely used, because it has many good properties, such as high strength, high hardness and low manufacturing cost etc. It has become a good substitute of parts for aluminum alloy, copper alloy and cast iron. But there are also disadvantages for ZA alloy, such as poor toughness and ductility, low corrosion resistance etc. In order to solve these problems, the effects of Zr addition and heat treatment process on the microstructure and mechanical properties of the ZA35 alloy has been studied using multi-function electronic test enginery, X-ray diffraction analysis and scanning electron microscope. The corrosion resistance of ZA35 alloy is also observed by electrochemical workstation.The results show that the refinement result of the ZA35 alloy with 0.3% Zr addition is better than others, the dendrite microstructure of the alloy is transformed from coarse to the floccus, and the tensile strength and elongation of the ZA35 alloy are relatively improved. The element Zr in the ZA35 alloy is partly solid solute inα-Al matrix, and the rest mainly exists in the form of Al3Zr compounds.The optimal solid solution process, aging and uniformization of the ZA35-0.3%Zr alloy are 340℃×1h , 120℃×4.5h and 370℃×24h respectively, and these have improved the microstucture and properties of the alloy.Under the electrochemical corrosion condition, in 3.5% NaCl and 4% NaOH solution, the open circuit potential of the Zr alloy become more positive, corrosion current density is decreases, that means the addition of Zr increases the corrosion resistance of original alloy by compared with the ZA35 alloy.