脉冲频率及占空比对Ti6Al4V合金微弧氧化膜层微观结构及性能的影响  

Effect of pulse frequency and duty ratio on microstructure and properties of microarc oxidation coating on Ti6Al4V alloy

作　　者：陈宇科 原梅妮[1] 周鹏飞 杭瑞月 李茂华 Chen Yuke;Yuan Meini;Zhou Pengfei;Hang Ruiyue;Li Maohua(College of Mechatronic Engineering,North University of China,Taiyuan Shanxi 030051,China;School of Materials Science and Engineering,Taiyuan University of Technology,Taiyuan Shanxi 030024,China;School of Materials Science and Engineering,Hunan University of Science and Technology,Xiangtan Hunan 411201,China)

机构地区：[1]中北大学机电工程学院,山西太原030051 [2]太原理工大学材料科学与工程学院,山西太原030024 [3]湖南科技大学材料科学与工程学院,湖南湘潭411201

出　　处：《金属热处理》2023年第6期9-15,共7页Heat Treatment of Metals

摘　　要：研究了脉冲频率及占空比对Ti6Al4V合金在Na_(2)SiO_(3)-Na(PO_(4))_(6)电解液体系中制备的微弧氧化膜层微观结构及其性能的影响,采用扫描电镜、能谱仪、X射线衍射仪、涂层厚度仪、激光共聚焦显微镜及显微硬度计对膜层形貌、元素分布、相组成、厚度、粗糙度及硬度进行测试表征。结果表明,Ti6Al4V合金微弧氧化膜层主要元素组成为Ti、O、Si等,物相组成主要为Rutile-TiO_(2)、Anatase-TiO_(2)及非晶相SiO_(2),随脉冲频率增加,膜层中Anatase衍射峰强度先降低后增加,Rutile呈相反趋势;随脉冲占空比增大,Anatase衍射峰强度逐渐减小,而Rutile衍射峰强度逐渐增加。膜层表面均匀分布微米级孔洞,脉冲频率对膜层微观形貌及粗糙度影响较小,膜层厚度先增大后减小;随占空比增加,膜层快速增厚,但表面逐渐出现微裂纹及局部烧蚀等缺陷,膜层粗糙度大幅增加,600 Hz、20%占空比时膜层厚度达45.46μm,粗糙度R_(a)为4.75μm。随脉冲频率及占空比增加,膜层显微硬度均呈现先增大后减小的变化规律,频率600 Hz、占空比20%时达最大值863.2 HV0.5,相比Ti6Al4V合金提高了149.5%。Effects of pulse frequency and duty ratio on microstructure and properties of microarc oxidation coatings prepared on Ti6Al4V alloy in Na_(2)SiO_(3)-Na(PO_(4))_(6)electrolyte system were studied.The morphology,element distribution,phase composition,thickness,roughness and microhardness of the coatings were characterized by means of scanning electron microscope,energy dispersive spectrometer,X-ray diffractometer,coating thickness meter,laser confocal microscope and microhardness tester.The results show that the main elements of Ti6Al4V alloy microarc oxidation coatings are Ti,O and Si.The phase composition is mainly Rutile-TiO_(2),Anatase-TiO_(2)and amorphous SiO_(2).With the increase of pulse frequency,the intensity of Anatase diffraction peak in the coating decreases first and then increases,whereas Rutile shows the opposite trend.With the increase of pulse duty ratio,the intensity of Anatase diffraction peak decreases,while that of Rutile diffraction peak increases.Micro-holes are uniformly distributed on the surface of the coatings.Pulse frequency has little effect on the microstructure and roughness,and the thickness increases first and then decreases.With the increase of duty ratio,the thickness increase rapidly,but the surface gradually appears microcracks and local ablation defects,causing the roughness increase rapidly.The thickness reaches 45.46μm and the roughness R_(a)is 4.75μm at 600 Hz and 20%duty ratio.With the increase of pulse frequency and duty ratio,the microhardness of coatings increases first and then decreases.The maximum microhardness is 863.2 HV0.5 at 600 Hz and 20%duty ratio,compared with Ti6Al4V alloy,the increase is 149.5%.

关 键 词：TI6AL4V合金 微弧氧化 脉冲频率 占空比 

分 类 号：TG174.41[金属学及工艺—金属表面处理]