In this study, Ti-6Al-4V (TC4) coating was prepared using an in situ shot peening-assisted cold spraying technology in which large shot peening particles were mixed with TC4 spraying powders to prepare the deposit. To improve its strength and toughness, the coating was heat-treated at 600-1000 °C in vacuum. The results demonstrated that the microstructure of the as-sprayed coating exhibited a special structure that was denser at the regions tamped by the shot peening particles and porous at the nontamped regions. When the coating was heat-treated at 800 and 1000 °C, the interface between the particles had largely disappeared and the local pores had interconnected with each other due to thermal diffusion and recrystallization. The coating hardness decreased slightly after annealing at 600 and 800 °C due to the released strain hardening effect. The bonding strength of the coating after annealing improved in comparison with that of the as-sprayed coating. The tensile strength of the coating improved significantly under annealing at 800 °C. A cross-linked high densification network was formed after annealing due to the effect of in situ shot peening, which served as a reinforced framework and enhanced the strength of the coating.

中文翻译：

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冷喷涂Ti-6Al-4V涂层热处理后交联高致密化网络的组织与强化机制

在这项研究中，Ti-6Al-4V (TC4) 涂层是使用原位喷丸辅助冷喷涂技术制备的，其中大的喷丸颗粒与 TC4 喷涂粉末混合以制备沉积物。为了提高其强度和韧性，涂层在真空中在 600-1000°C 下进行热处理。结果表明，喷涂态涂层的微观结构表现出一种特殊的结构，在被喷丸颗粒夯实的区域更致密，而在未夯实的区域则是多孔的。当涂层在 800 和 1000 °C 下进行热处理时，由于热扩散和再结晶，颗粒之间的界面已基本消失，局部孔隙相互连通。由于释放的应变硬化效应，涂层硬度在 600 和 800 °C 退火后略有下降。与喷涂后的涂层相比，退火后涂层的结合强度有所提高。涂层的拉伸强度在 800°C 退火后显着提高。由于原位喷丸处理的作用，退火后形成了交联的高致密网络，起到了增强骨架的作用，提高了涂层的强度。