摘要
为了研究冷却方式对等离子喷涂热障涂层残余应力的影响规律,基于热弹塑性有限元理论,并利用ANSYS有限元软件,建立了等离子喷涂Mo/8YSZ热障涂层的数值模型,模型中考虑了材料不同温度下的热物性参数,研究了在同步冷却和滞后冷却两种冷却方式下喷涂构件残余应力的分布情况及变化趋势。结果表明:伴随着对流换热系数的增加,喷涂构件的最大径向残余拉应力逐渐减小,而最大径向残余压应力呈现先减小后增大的变化趋势;采用空气自然冷却、压缩空气冷却或静水冷却的方式对喷涂构件进行冷却处理时,喷涂构件的最大轴向残余拉应力小于最大轴向残余压应力,当采用循环水冷却时,喷涂构件的轴向残余拉应力大于轴向残余压应力;伴随着滞后冷却时间间隔的增加,喷涂构件的最大轴向残余拉应力增大,最大轴向残余压应力减小,最大径向残余应力与最大剪残余应力的变化不明显;当滞后冷却时间间隔在0~60 s范围时,喷涂构件残余应力影响变化不明显;涂层剥离失效的大概率位置位于相异涂层界面或基体与涂层界面下方0.2~0.4 mm区间范围内,且伴随着滞后冷却时间间隔的增加及对流换热系数的增加,涂层缺陷的萌发位置逐渐向界面边缘转移。通过合理调控等离子喷涂作业的冷却方式,可实现喷涂构件的残余应力合理分布,进一步提升基体与涂层的结合强度。
In order to study the influence of cooling modes on the residual stress of plasma-sprayed thermal barrier coatings,the numerical model of Mo/8YSZ thermal barrier coatings was established based on the thermoelasticplastic finite element theory and by using ANSYS finite element software.The thermal and physical properties of materials at different temperatures were considered in the model,and the distribution and variation trend of residual stress of spraying components under synchronous cooling and lag cooling were studied.The results showed that with the increase of convection heat transfer coefficient,the maximum radial residual tensile stress of the spray components decreases gradually,while the maximum radial residual compressive stress first decreases and then increases.The maximum axial residual tensile stress is less than the maximum axial residual compressive stress when spraying components are cooled by AN air natural,compressed air or static water.When cooling with circulating water,the axial residual tensile stress of spraying components is greater than that of axial residual compressive stress;With the increase of lag cooling time interval,the maximum axial residual tensile stress increases,the maximum axial residual compressive stress decreases,and the maximum radial residual stress and maximum shear residual stress do not change obviously.When the lag cooling time interval is within the range of 0~60 s,the influence of residual stress on spray components is not obvious.The most likely location of coating peel failure is within the range of 0.2~0.4 mm below the interface of dissimilar coating or substrate and coating,and with the increase of hysteresis cooling time interval and convection heat transfer coefficient,the germination position of coating defects gradually transfers to the interface edge.By adjusting the cooling mode of plasma spraying reasonably,the residual stress distribution of spraying components can be reasonably realized,and the bonding strength of substrate and coating can be furthe
作者
崔艳雨
张啸寒
庞铭
Cui Yanyu;Zhang Xiaohan;Pang Ming(Airport College,Civil Aviation University of China,Tianjin 300300,China)
出处
《中国稀土学报》
CAS
CSCD
北大核心
2020年第2期196-207,共12页
Journal of the Chinese Society of Rare Earths
基金
国家自然科学基金项目(U1633111,51206179)
中央高校基本科研业务费项目中国民航大学专项项目(3122018D020)
中国民航大学蓝天青年科研资金资助项目
中央高校基本科研业务费项目(201909)资助。
关键词
等离子喷涂
热障涂层
冷却方式
残余应力
数值模拟
稀土
plasma spraying
thermal barrier coating
cooling mode
residual stress
numerical simulation
rare earths
