基于涡流锁相热成像的刹车片内部气泡检测

摘要

Brake block is an essential part of auto brake parts,and its inner air bubbles seriously affect driving safe-ty.Traditional sound detection method has strong subjectivity,low efficiency,difficult to meet the accurate and high ef-ficient detection requirements.The detection method based on eddy current lock-in thermography is applied to detect air bubble in less metal friction material brake blocks as it has the characteristics of the non-contact and large area in-spection.In order to investigate the effect of structure and inner air bubble on phase,finite element method is adopt-ed.Taking back side steel phase as a reference,the air bubbles were separated.The brake block was tested,and the same defect also can be seen after water cutting.Experiment results show that eddy current lock-in thermography de-tection method can effectively detect air bubbles in less metal friction material brake blocks.%刹车片是汽车必不可少的制动部件，其内部气泡严重影响行车安全。传统敲击听声检测方法主观性强，检测效率低，难以满足准确高效的检测需求。基于涡流锁相热成像具有非接触、大面积检测的特点，将其应用于少金属摩擦材料汽车刹车片的内部气泡检测。采用有限元仿真探索了刹车片结构和内部气泡对相位的影响，并以背钢处相位为参考，分离出气泡存在。对刹车片试样进行检测，并采用水切割观察剖面的方法验证结果。实验表明涡流锁相热成像检测方法能有效检测少金属摩擦材料汽车刹车片的内部气泡。