摘要
采用等离子喷涂技术在钛合金表面制备了(HA+5wt%CaB_(6))+0.4wt%La_(2)O_(3)/HA+50wt%Ti(过渡层)的复合涂层,并对该涂层经热处理与激光重熔后进行对比研究。对比研究了两种不同工艺对等离子喷涂涂层的晶化率、形貌和物相及缺陷的影响,并研究了在模拟体液(SBF)环境下两种不同工艺下涂层的电化学腐蚀性能。结果表明,热处理温度从550℃升高到850℃,晶化转变率逐渐提高,但温度超过650℃时,会出现裂纹;激光重熔功率从30 W升高到150 W,晶化转变率也逐渐提高,但裂纹会增多,当激光功率达到120 W时,局部甚至会出现严重的剥落现象。通过进一步研究发现,在热处理温度为550℃到到850℃之间,涂层的各衍射峰位置和相转变均没有发生,但经激光重熔后,随着激光功率密度提高,涂层的衍射峰强度会出现增强和减弱,并晶体的择优取向发生了改变。最后,对等离子喷涂涂层经热处理(650℃保温2 h)和激光重熔(50 W)后的耐腐蚀性能结果对比,热处理后涂层腐蚀电流密度I_(corr)=5.1871×10^(-7)A⋅cm^(-2);激光重熔腐蚀电流密度I_(corr)=3.6503×10^(-6)A⋅cm^(-2),I_(corr)值越高的材料越容易腐蚀,即热处理涂层具备更优异的耐腐蚀性能。
A composite coating of(HA+5wt%CaB_(6))+0.4wt%La_(2)O_(3)/HA+50wt%Ti(transition layer)was prepared on the surface of titanium alloy by plasma spraying technology,and the coating was compared after heat treatment and laser remelting.The effects of two different processes on the crystallization rate,morphology,phase and defects of plasma sprayed coatings were compared,and the electrochemical corrosion performance of the coatings in simulated body fluid(SBF)environment was also studied.The results show that when the heat treatment temperature increases from 550℃to 850℃,the crystallization transformation rate gradually increases,but when the temperature exceeds 650℃,cracks will appear.With the increase of laser remelting power from 30 W to 150 W,the crystallization transformation rate will gradually increase,but cracks will increase.When the laser power reaches 120 W,even severe spalling will occur locally.Through further study,it was found that the diffraction peak position and phase transition of the coating did not occur between 550℃and 850℃,but after laser remelting,with the increase of laser power density,the diffraction peak intensity of the coating increased and decreased,and the preferred orientation of the crystal changed.At last,the corrosion resistance results of plasma sprayed coatings after heat treatment(650℃for 2 h)and laser remelting(50 W)were compared,and the corrosion current density I_(corr)=5.1871×10^(-7)A⋅cm^(-2) after heat treatment.The laser remelting corrosion current density I_(corr)=3.6503×10^(-6)A⋅cm^(-2),and the higher the I_(corr) value,the easier the material is to corrode,the heat-treated coating has better corrosion resistance.
作者
贺冬
林英华
刘京晋
周浩
陈皓
王新林
He Dong;Lin Yinghua;Liu Jingjin;Zhou Hao;Chen Hao;Wang Xinlin(School of Mechanical Engineering,University of South China College,Hengyang,Hunan 421001,China;Ultra-fast Wiener Technology and Laser Advanced Manufacturing Hunan Provincial Key Laboratory,University of South China College,Hengyang,Hunan 421001,China;School of Electrical Engineering,University of South China College,Hengyang,Hunan 421001,China)
出处
《机电工程技术》
2022年第3期99-103,154,共6页
Mechanical & Electrical Engineering Technology
