Pr(NO3)3对ZA31镁合金微弧氧化涂层组织与性能的影响  

Effects of Pr(NO3)3 on microstructure and properties of ZA31 magnesium alloy micro-arc oxide coating

作　　者：孙科文 张云龙[1] 李文博 李成海[1] 潘佳琦 尹冬松[1] 胡明[1] 王涛[1] Sun Kewen;Zhang Yunlong;Ii Wenbo;Li Chenghai;Pan Jiaqi;Yin Dongsong;Hu Ming;Wang Tao(College of Materials Science and Engineering,Jiamusi University,Jiamusi 154007,China)

机构地区：[1]佳木斯大学材料科学与工程学院,黑龙江佳木斯154007

出　　处：《轻金属》2020年第4期46-51,共6页Light Metals

基　　金：国家自然科学基金资助项目(51671096);黑龙江省自然科学基金(E2015038);黑龙江省教育厅科学研究项目(2016-KYYWF-0556,2017-KYYWF-0582);佳木斯大学科学研究项目(Lz2013-014,L2012-007)。

摘　　要：针对生物医用镁合金耐蚀性差的问题,利用微弧氧化技术对ZA31镁合金进行表面改性处理,旨在获得抗腐蚀性优良的陶瓷涂层。在已优化的硅酸盐电解液体系和电化学参数条件下,对ZA31镁合金进行微弧氧化处理,研究电解液中Pr(NO3)3含量对微弧氧化涂层的相组成、微观结构、润湿角、表面粗糙度以及电化学性能的影响。研究结果表明:在电解液中添加Pr(NO3)3后获得的ZA31镁合金涂层主要由MgO、MgSiO3和Mg2SiO4等晶相组成,未检测到Pr的氧化物相。未添加Pr(NO3)3时,涂层具有火山口状的微孔结构。随着Pr(NO3)3添加量增加,涂层表面的孔洞和火山状凸起减少,孔洞尺寸也明显减小,伴随出现大量表面平滑的区域,表面粗糙度降低。当Pr(NO3)3添加量不同时,涂层表面粗糙度在1.8~2.4μm范围内变化。在电解液中添加Pr(NO3)3后,涂层的极化曲线向正电位方向移动,涂层腐蚀电位正移,但幅度变化不大,腐蚀电流降低约为1~2个数量级,涂层的耐蚀性提高。With respect to the poor corrosion resistance of biomedical magnesium alloys,ZA31 magnesium alloys were treated by micro-arc oxidation technology in order to obtain a ceramic coating with excellent corrosion resistance.ZA31 magnesium alloy was treated by micro-arc oxidation under the optimized silicate electrolyte system and electrochemical parameters.The effect of Pr(NO3)3 content in the electrolyte on the phase composition,micro-structure,wetting angle,surface roughness and electrochemical properties of the micro-arc oxidation coating was investigated.The results showed that ZA31 magnesium alloy coating obtained by adding Pr(NO3)3 to the electrolyte was mainly composed of MgO,MgSiO3 and Mg2SiO4 phases,meanwhile,the oxide phase of the original added Pr had not been detected.The coating without Pr(NO3)3 had a crater-like microporous structure.With the increase of Pr(NO3)3 content,the holes and volcanic protrusions on the coating surface decreased,then the hole size also decreased significantly,accompanied by a large number of smooth surface areas and decreased surface roughness.Under different Pr(NO3)3 content,the surface roughness of coating varied from 1.8 jxm to 2.4 jxm.After Pr(NO3)3 was added into the electrolyte,the polarization curve of the coating moved towards the positive potential,and the con^osion potential of coating was positively shtfted,but the range was not changed obviously,the corrosion current dropped by about 1〜2 ordere of magnitude,then the corrosion resistance of the coating improved.

关 键 词：ZA31镁合金 微弧氧化涂层 润湿行为 稀土硝酸盐 

分 类 号：TG174[金属学及工艺—金属表面处理]