Study On Corrosion Dynamics And Mechanism Of Spray Forming ZA35 Alloy With High Mn

ZA35 alloy has excellent mechanical properties, good casting and processing performance, exceptional wear resistance, and wide source of raw materials, low cost, pollution-free. It is one of the new and rapidly developing alloys both at home and abroad. However the corrosion and failure caused by aging which impacts on its wider use, has not yet been effectively solved. In view of this question, looking forward to improve the corrosion resistance of zinc-aluminum alloy.ZA35 alloys prepared by spray forming technology with high alloying element Mn. spray test,corrosion potential test and potentiodynamic polarization were used to study spray forming ZA35-3.5%Mn alloy in this paper.The results show that the curve of corrosion dynamics of spray forming alloy is parabola under the salt spray corrosion condition, corrosion rate of the alloy with Mn has lower than that of the alloy without Mn; The corrosion reason is the dissolution of phase.The soild solubility of Mn in ZA35 matrix is considerably shifted to a higher level by spray foeming, so the potential difference betweenηphase andαphase decreases. Therefore,the corrosion rate can be limited.Under the electrochemistry corrosion condition, the corrosion potential of spray forming ZA35-3.5%Mn alloy changes to positive value and the corrosion current density reduces compared with the spray forming ZA35 alloy in 3.5% NaCl, also in 4%NaOH and 10%H₂SO₄. The results of consideration indicate that corrosion rate of spray forming ZA35-3.5%Mn alloy is lower than that of spraying forms the ZA35 alloy.So spray forming ZA35-3.5%Mn alloy has good corrosion resistance.In 3.5% NaCl solution, Cl- can promote Zn anodic dissolution, and the polarization of the alloy is under the control of activation polarization, there is no apparently passive behavior. In the 4% NaOH solution, the alloy apparent passivation. In 10% H₂SO₄ solution, the alloy polarization in the activation of polarization control. While the Corrosion rate of three alloys increases on the basis of 3.5%NaCl,4%NaOH,10%H₂SO. And as the solution temperature increases, the corrosion rate of alloy in three kinds of solution gradually increases.The corrosion trend can be increased by the treatment of solid solution and aging.