Effect of minor RE addition on microstructures and mechanical properties of AZ31 magnesium alloy
(1.江苏省苏州市苏州有色金属研究院
2.Suzhou Institute for Nonferrous Metals Processing Technology, Suzhou 215026, China)
2.Suzhou Institute for Nonferrous Metals Processing Technology, Suzhou 215026, China)
Abstract: AZ31 alloy with minor RE addition was investigated. The material was homogenized, hot-rolled and annealed. Optical microscopy, scanning electron microscopy and X-ray diffractometry were employed to characterize the microstructures of AZ31 alloy with RE addition. And micro-hardness test was employed to measure mechanical properties of annealed material. The results show that minor RE addition (0.3% is mass fraction) has little effect on the grain size of as-cast AZ31 alloy, and only Mg17(Al, Zn)12 phase was found in the microstructure of as-cast AZ31RE alloy. The result of X-ray diffraction shows that supersaturation of alloying elements has little effect on the lattice parameters of the α-Mg in homogenized sample; but owing to RE solute with high melting point, AZ31RE alloy exhibits better heat resistance than AZ31 alloy.
Key words: rare earth; AZ31 alloy; microstructures; properties; grain refinement