1、 Rare Metal Materials and Engineering Volume 40,Suppl.3,October 2011 Received date:January 15,2011 Foundation item:Science and Technology Department of Zhejiang Province Fund(2007c21139);Youth Science Foundation of China(10802083);Ningbo Branch of China Academy of Ordnance Science Fund Corresponding
2、 author:Zheng Shunqi,Ningbo Branch of China Academy of Ordnance Science,Ningbo 315103,P.R.China,E-mail: Copyright 2011,Northwest Institute for Nonferrous Metal Research.All rights reserved.290ARTICLECite this article as:Rare Metal Materials and Engineering,2011,40(S3):290-293.Tribological Behavior o
3、f Magnesium Alloy by Composite Treatment Tribological Behavior of Magnesium Alloy by Composite Treatment Zheng Shunqi1,Zhang Gaohui2,Huang Guoqing2,Xu Peng2,Li Gen2 1 Ningbo Branch of China Academy of Ordnance Science,Ningbo 315103,China;2 China Jiliang University,Hangzhou 310018,China Abstract:A co
4、mpact and homogeneous composite membranous layer was coated on the surface of AZ31 magnesium alloy by a multiple treatment of micro-arc oxidation,magnetron sputtering,and ion implantation in order to improve the wear-resistance performance and micro-arc oxidation surface of the magnesium alloy.X-ray
5、 diffraction(XRD)and metallurgical microscopy as well as scanning electron microscopy(SEM)were used to identify the phases structures of the coating and worn surface.The dry sliding wear behavior of the composite membranous layer was performed on WTM-2E tribological and wear tester.The results show
6、that the ceramic coating formed by micro-arc oxidation is not uniform,and lots of holes can be founded on the surface.While a uniform composite membranous layer with TiN can be formed on the surface of the magnesium alloy by the multiple treatment technology,and the porosity of this layer is also re
7、duced.And the multiply treated sample shows good anti-wear performance in dry sliding against the steel,the width of the wear trace is 227.5767 m which is only 66%of the micro-arc oxidation one as the sliding distance reaches 175 m.Key words:magnesium alloy;micro-arc oxidation;multiple treatment;sli
8、ding wear Magnesium alloy has numerous of advantageous properties such as high specific strength,high damping characteristics,excellent mechanical processing properties and polished performance,non-toxic,non-magnetic,high thermal conductivity,as well as easy recycle.These properties make magnesium a
9、lloy valuable in a number of applications including cars,computers,mobile phones,precision instruments,defence and aerospace as well as many other fields1-6.However,the magnesium alloy with poor chemical stability is unstable in most media7,8.Thus,the surface treatment technology can be one feasible
10、 way to expand the applications of magnesium alloy.Many surface treatment methods such as anodic oxidation9,micro-arc oxidation10-12,chemical conversion film13,monomolecular film14,and ultrahard coating(AlN/TiN)15,16 etc have been used to improve the wear resistant and the corrosion resistant of mag
11、nesium alloy.The reaches show that the micro-arc oxidation and metal nitriding are good ways to improve the wear resistance and the corrosion resistance of the samples,but the surface condition is poor.In order to improve the wear resistant performance of AZ31 magnesium alloy,two methods have been e
12、mployed.One is to coat a ceramic layer on the surface of magnesium alloy by using micro-arc oxidation.The other one forms a layer with the phase of TiN by diffusing Ti on the surface of the sample treated by micro-arc oxidation,then infusing N by iron implantation.1 Experimental1 Experimental AZ31 m
13、agnesium alloy disks with diameter of 60 mm and thickness of 5mm(Al 3.0%-4.0%,Zn 1.0%,Mn 0.2%-0.8%,the remaining is Mg)have been chosen as the substrate.The substrates had been cleaned,polished by the SiC sandpaper(200#to 2000#)and polishing machine,then were put in an ultrasonic acetone-bath for 5
14、min.The treatment of micro-arc oxidation is consisted of a alternating current power supply unit,a stainless container,a stirring and cooling system.The substrates were treated by micro-arc oxidation after polishing and hanging,then washing and daring.During the process of micro-arc Zheng Shunqi et
15、al./Rare Metal Materials and Engineering,2011,40(S3):290-293 291 oxidation,the samples were treated in the solution of 30-60 g/L Na2SiO3 and 20-40 g/L NaOH as well as little additive.The current and the final voltage were taken as 2 A and 280 V respectively,and the working time was 10 min.Multiple t
16、reatment was carried out by MIB-700 Multi-ion beam co-sputtering equipment.Ti had been diffused on the sample treated by micro-arc oxidation,and then N2 was implanted to form a TiN layer by iron implantation.The parameters of the magnetron sputtering and iron implantation processes are listed in Tables 1 and 2,respectively.D/MAX-Ultima IV X-ray diffraction(XRD)has been employed to analyze the phase structures of the samples.The morphologies can be observed by JEOL JSM-5610LV scanning electron mi
