Effect of substrate hardness and spray angle on the deposition behavior of cold sprayed Ti particles

In this study, finite element analysis combined with experimental observation was conducted to clarify the effect of substrate hardness and spray angle on the deposition behavior of cold sprayed Ti particles. It is found that both the particle and substrate deform intensively after Ti particle depositing on Cu substrate. The contact area between the particle and substrate is large. Metallurgical bonding is highly possible to occur and thus large coating thickness is achieved. For Ti particle depositing on soft Al substrate, although the contact area is smaller, the particle can be trapped by the soft substrate material. Mechanical interlock is formed between the particle and substrate. Therefore, the final coating thickness is also relatively large. However, when using hard stainless steel as substrate, the contact area between the particle and substrate is small. Mechanical interlock is lack and the first layer coating is difficult to be formed. Hence, the thickness of the final coating is rather small. Furthermore, it is also found that with decreasing the spray angle, the interfacial contact area and coating thickness decrease, but the coating porosity increases gradually.