Microstructure change of AZ91 magnesium alloy surface melted by laser

XU Ren-jun; ZHANG Yong-kang; CHEN Ju-fang

In order to study the surface tissue variation of the magnesium alloy treated by laser,the surface of AZ91 magnesium alloy was treated by CO2 laser under the protection of helium gas.The treated workpiece was observed through optical microscope,and the microhardness value of the cross section was tested by microhardness tester.The result of the experiment showed that the grain size of the treated magnesium alloy was refined to the primitive magnesium alloy,the grain size of the magnesium alloy becoming smaller with the decrease of the scanning speed,and that the β phase along the grain boundary decreased distinctly.The microhardness test of the cross section showed that the microhardness value of the treated section enhanced distinctly,and the smaller of the grain size,the harder of the cross section,according to the Hall-Petch formula.

Corresponding author: ZHANG Yong-kang, ykzhang@ujs.edu.cn;

1. School of Mechanical Engineering, Jiangsu University, Zhenjiang 212013, China

Received Date: 2007-07-03

Accepted Date: 2007-12-24

Available Online: 2008-10-25

Abstract: In order to study the surface tissue variation of the magnesium alloy treated by laser,the surface of AZ91 magnesium alloy was treated by CO2 laser under the protection of helium gas.The treated workpiece was observed through optical microscope,and the microhardness value of the cross section was tested by microhardness tester.The result of the experiment showed that the grain size of the treated magnesium alloy was refined to the primitive magnesium alloy,the grain size of the magnesium alloy becoming smaller with the decrease of the scanning speed,and that the β phase along the grain boundary decreased distinctly.The microhardness test of the cross section showed that the microhardness value of the treated section enhanced distinctly,and the smaller of the grain size,the harder of the cross section,according to the Hall-Petch formula.

HTML

Reference (11)

[1]	LEI M K,LI P,YANG H G,et al.Wear and corrosion resistance of Al-ion implanted AZ31 magnesium alloy[J].Surface Coatings Technology,2007,201(9/11):5182-5185.
[2]	ABBAS G,LIU Z,SKELDON P.Corrosion behavior of laser-meltedmagnesium alloys[J].Applied Surface Science,2005,247(1/4):347-353.
[3]	GAO Y L,WANG C Sh,LIU H B,et al.Grain refinement of AZ91HP magnesium alloy treated by vacuum laser melting[J].Transactions of Materials and Heat Treatment,2006,27(1):92-95(in Chinese).
[4]	LIU Zh,ZHANG K,ZENG X Q.Theoretical basis and application of magnesium-based alloy[M].Beijing:China Machine Press,2002:1-14(in Chinese).
[5]	CHEN Zh H.Magnesium alloys[M].Beijing:Chemical IndustryPress,2004:203-204(in Chinese).
[6]	ZHANG H Y,LI H L,GUO Y N.Study of corrosion resistance of chemical conversion coatings on magnesium alloys substrate[J].Materials Protection,2007,40(1):10-12(in Chinese).
[7]	QIAN J G,LI D,WANG Ch,et al.EIS study on corrosion process of anodized film on AZ91D magnesium alloy[J].Raremetal Materials and Engineering,2006,35(8):1280-1284(in Chinese).
[8]	MIAO Y J,SHEN Ch J,LIU J J.Corrosion resistance of ceramic layer on AZ91D magnesium alloy formed by micro-arc oxidation[J].Light Alloy Fabrication Technology,2006,34(10):43-46(in Chinese).
[9]	GUO H F,AN M Zh.Electroplating and electroless plating on magnesium and its alloys[J].Electroplating Pollution Control,2004,24(2):1-5(in Chinese).
[10]	WANG X F,LU X D,CHEN G N,et al.Simulation and verification of the temperature field in laser hardening[J].Laser Technology,2004,28(2):162-165(in Chinese).
[11]	LI H Q,XING D M,TONG J W,et al.Relationship between yield stress and microcosmic structure of nanostructured material[J].Journal of Tianjin University,2000,33(5):671-674(in Chinese).

Microstructure change of AZ91 magnesium alloy surface melted by laser

Abstract

References

Proportional views

通讯作者: 陈斌, bchen63@163.com

Proportional views