PVD coatings and their failure behavior under extreme high contact stresses

物理气相沉积（PVD）涂层可以策略性地应用于安装在可能发生严重磨损的区域的相对较小的冲压模具镶件上。这种方法很可能是必要的，因为PVD涂层比电镀或化学涂层和氮化钢具有更高的硬度和耐磨性。在实际生产应用之前，实验室测试通常用于评估PVD涂层。剥落是冲压应用中PVD硬质涂层的主要失效机制，在与实际生产不相符的操作条件下进行的实验室测试中无法观察到剥落。本研究将选择销盘式滑动磨损试验、球盘式冲击疲劳试验和超高接触应力下附加滑动运动的扩展冲击疲劳试验作为加速实验室试验，模拟剥落失效的磨损情况。

Physical vapor deposition (PVD) coatings can be strategically applied on relatively small stamping die inserts which are installed in the areas where severe wear may occur. This approach is most likely necessary because PVD coatings can have a much higher hardness and wear resistance than electroplated or electroless coatings and nitrided steels. Lab tests are usually used to evaluate the PVD coatings before actual production applications. Spallation is the main failure mechanism of PVD hard coatings in stamping applications, which can not be observed in lab tests conducted in operating conditions that do not correspond to actual productions. In the proposed research, pin-on-disc sliding wear tests, ball-on-plate impact fatigue tests, and extended impact fatigue tests with additional sliding motions under ultra high contact stress will be chosen as the accelerated lab tests to simulate the wear conditions of spallation failures.