利用应力波测量涂层的结合强度

Measurement of Bond Strength of Coating Using Stress Wave

基于探索评价涂层抗拉结合强度方法的目的,考虑到激光冲击法测量涂层的抗拉伸结合强度时应力难于测量的情况,依据一维应力波的线性理论:在杆的一端撞击产生一压应力脉冲,此脉冲传到自由端后将反射为拉应力脉冲,当在杆的自由端有涂层薄膜时这一应力对涂层界面产生拉伸作用,如果这一应力幅值足够大就会将其拉开,以此实现抗拉结合强度测量。文中分析了应力波在涂层界面处产生拉应力的规律,利用Hopkinson压杆技术产生和测量应力脉冲。以此测量了铁基涂层的结合强度,证明了方法的有效性。

A way of measuring tensile bond strength of coating is presented in this paper. When a compressive stress pulse is generated by an impact at one end of a bar, the pulse reflected from the other end （free end） becomes a tensile wave in terms of the one dimension linear theory of stress wave. If a film is coated on the surface of the free end, the tensile stress acts on the coating interface, and in case of large enough amplitude, the coating can be pulled apart. In above mentioned method, the measurement of tensile bond strength of coating can be accomplished. The characteristics of tensile stress produced on the coating interface by stress pulse were analyzed. Stress pulses were obtained and tested using Hopkinson pressure bar technique. The bond strength of an iron-base coating material was measured and the validity of the method was proved.