Deposition mechanism of ceramic reinforced metal matrix composites via cold spraying
Zhongyu Wang, Pengcheng Mao, Chunjie Huang, Pengfei Yu, Wenya Li, Shuo Yin
Abstract
Understanding the mechanism underlying metal matrix composites (MMCs) in cold spraying is critical to fabricate innovative MMC coatings and deposits with tailored microstructures and excellent mechanical performance. In this work, we propose a systematic numerical simulation framework combined with experimental observations to reveal the co-deposition mechanism of cold-sprayed metal/ceramic MMCs. The finite element modeling results and experimental validation found some critical conclusions regarding the deposition mechanism. The modeling results show that most of alumina particles are significantly fractured in Inconel718/alumina coating in contrast to aluminum/alumina coating. This fact suggests that the critical fragmentation velocity (CFV) of ceramic particles is dependent on the hardness of the metal substrate/matrix. Ceramic particles are more prone to fracture when co-deposited with metals having high hardness. Moreover, the simulation results also indicate that the rebounded alumina particles or fragments are possibly captured by incoming metal particles and trapped into MMCs. Since intact alumina particles are barely seen in composites, especially when co-deposited with hard metals, it can be concluded that direct ceramic particle deposition significantly relies on fragmentation. In addition, secondary fragmentation plays a key role in the metal-ceramic co-deposition process. The particles that have completed the impact process may be subjected to secondary fragmentation in the form of new cracks and fragmentation due to the impact by following metal and ceramic particles. • A systematic numerical method was presented for unveiling metal-ceramic co-deposition by cold spraying. • The critical fragmentation velocity of ceramic particles was quantitatively identified and studied. • The essence of the deposition mechanism of ceramic particles in cold spraying was revealed utilizing energy analysis. • Numerical methods unravelled the secondary fragmentation of ceramic particles during the co-deposition process. • The metal-ceramic co-deposition mechanism in cold spray was elaborated with simulation and experimentation.