基于涂层技术的薄壁止裂试验研究

EXPERIMENTAL STUDY ON THIN WALL CRACK ARREST BASED ON COATING TECHNOLOGY

工程薄壁结构长期受到交变载荷作用,产生疲劳裂纹且多为贯穿性裂纹,进而导致修复困难和工程中不能替换问题,因此提出一种涂层技术对薄壁结构修复和止裂。制作与实际工程相关的薄板试验件,并预置裂纹。试验件在振动试验台做1阶弯曲共振状态和基础激励为10g的激励试验,直至出现微裂纹。采用双面喷涂方法对试验件进行NiCrAl涂层和NiCrAl过渡层+ZrO_(2)功能层复合涂层两种涂层设置修复裂纹,并重复激励试验。对比试验件涂层前后的裂纹扩展时间和扩展速率,分析NiCrAl涂层和ZrO_(2)涂层对带裂纹薄板试验件裂纹扩展的影响。验证涂层对薄壁板件的止裂效果。

Due to long-term alternating load,engineering thin-walled structures will produce fatigue cracks,and most of them are penetrative cracks,which will lead to difficult repair and irreplaceable problems in engineering.Therefore,a coating technology is proposed to repair and crack arrest thin-walled structures.Thin plate test pieces related to practical engineering were made,and cracks were preset.The test piece was going to be subjected to the first-order bending resonance state and the excitation test with the foundation excitation of 10 g on the vibration test bench until cracks appear.Two kinds of coatings,NiCrAl coating and NiCrAl transition layer+ZrO_(2) functional layer composite coating,were applied to the test piece by double-sided spraying method to repair the crack,and the excitation test was repeated.Comparing the crack propagation time and propagation rate of the test piece before and after coating,the influence of NiCrAl coating and ZrO_(2) coating on the crack propagation of the thin-walled plate test piece was analyzed.The crack arrest effect of the coating on the thin-walled plate is verified.