The retention and fragmentation of the polycrystalline ceramic particles have a significant influence on the properties of the cold sprayed coatings. In this computational study, polycrystalline ceramic models were developed which demonstrated that ceramic fragmentation and retention were influenced by particle grain sizes and their impact velocities. The underlying mechanisms of crack initiation and propagation were outlined. Larger grain sizes showed higher crater depths and lower rebounding velocities, while smaller grain sizes exhibited significantly lower fragmentation. Based on the results, an optimum grain size range was proposed for lower fragmentation and higher retention. Moreover, using multiple particles and first-layer crater models, the beneficial role of surrounding metal particles on reducing fragmentation has been clarified and compared to the experimental observations. The present work provides theoretical insights on the damage mechanism and retention of ceramics during metal-ceramic composite cold spraying.

多晶陶瓷颗粒的保留和破碎对冷喷涂涂层的性能有重大影响。在这项计算研究中，开发了多晶陶瓷模型，该模型表明陶瓷的碎裂和保留受到颗粒尺寸及其冲击速度的影响。概述了裂纹萌生和扩展的潜在机制。较大的晶粒尺寸显示较高的弹坑深度和较低的回弹速度，而较小的晶粒尺寸显示的碎屑明显较低。根据结果​​，提出了最佳的晶粒尺寸范围，以减少碎裂和提高保留率。此外，使用多个粒子和第一层火山口模型，周围金属颗粒在减少碎裂中的有益作用已得到阐明，并与实验观察结果进行了比较。本工作为金属陶瓷复合材料冷喷涂过程中陶瓷的损伤机理和保持提供了理论见解。