多冲载荷下表面涂层覆盖形式与基体开裂

The cover structure of surface coating on substrate and cracks in with multiple-impact load

对在多冲碰撞载荷下的激光厚涂层试件进行试验 ,发现涂层在基体上的全覆盖形式比部分覆盖形式的极限应力要低 ,但在相同多冲应力作用下寿命长。后者的基体在涂层覆盖区边缘下部会出现强烈的形变硬化与材料流动现象 ,同时此处容易产生裂纹并扩展 ,造成涂层脱落。

The multiple-impact experiment to chick coating test-piece was carried out.The experimental result showed that the edge limit-press of substrate covered fully by coating is lower to that covered partly by coating,but the life of the former is longer to the one of the latter.The intense deformation hardening and material flow will emerge in the substrate of the edge cover by coating,The region easily come into being cracks and fall away with the coating.