Improvement of microstructure,mechanical properties,and corrosion resistance of WE43 alloy by squeeze casting

摘要

The WE43 magnesium alloy was prepared by squeeze casting,and the influence of squeeze casting parameters on mechanical properties and corrosion resistance was studied and compared with gravity casting.The gravity cast WE43 alloy shows uneven grain size distribution,and some grains even greater than 90μm.While,the grain size of the squeeze cast WE43 alloy is mainly distributed in 20-50μm.The Mg12Nd2Y phase morphology changes from large lamellar to strips after squeeze casting,whereas Mg_(24)Y_(5) phase exhibits no obvious change.The yield strength,tensile strength,and elongation of the gravity cast WE43 alloy are 127 MPa,157 MPa,and 6%,respectively,and 145 MPa,193 MPa,and 9.1%for squeeze cast alloy.For the squeeze cast WE43 alloy,the average corrosion rate is 0.6056 mm·year^(-1) according to immersion test results,and according to electrochemical measurements,the corrosion current density is 78.13μA·cm^(-2),which is better than that of the gravity cast WE43 alloy.Compared with gravity casting,the grains and second phase of the WE43 alloy by squeeze casting are refined,and the mechanical properties and corrosion resistance are improved.This may expand the applications of the WE43 alloy.