The influences of Zn、Sb、Ti、Zr on the corrosion of ZL114A alloy

The corrosion behaviour of cast Al-Si alloys in 3.5%NaC1 solution has been studied by electrochemical and immersion corrosion tests,at the same time,the effect of Zn,Sb,Ti and Zr on corrosion potentials,corrosion current densities and corrosion properties of ZL114 alloys have been investigated in this paper.The morphologies of tested alloys before and after immersion corrosion were analyzed by SEM(scanning electron microscopy).The results of electrochemistry tests indicate that all the tested alloys may be passivated rapidly.The free corrosion potentials shifted to negative and the corrosion current densities of the alloys increased with the increasing of alloy elements.The results of immersion corrosion tests show that corrosion resistance of ZL114 alloy is decreased when it contains the testing alloy elements,especially the Zn.