Effects of Substrate Hardness and Spray Angle on the Deposition Behavior of Cold-Sprayed Ti Particles
Effects of Substrate Hardness and Spray Angle on the Deposition Behavior of Cold-Sprayed Ti Particles
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DOI：
10.1007/s11666-013-0039-0
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发表时间：
2014-01-01
影响因子：
3.1
通讯作者：
Wang, Xiaofang
中科院分区：
文献类型：
--
作者：
Yin, Shuo;Suo, Xinkun;Wang, Xiaofang
采用有限元分析和实验相结合的方法，研究了基体硬度和喷涂角度对冷喷涂Ti颗粒沉积行为的影响。结果表明，在Ti颗粒与Cu基体之间，由于界面边缘处强烈的金属射流有助于去除开裂的氧化物，因此Ti颗粒与Cu基体之间极有可能发生冶金结合。由于冶金结合和大的界面接触面积可以保证高的结合强度，因此在Cu基体上沉积后获得了厚的Ti涂层。对于软Al基体，第一层Ti颗粒嵌入并被软基体材料捕获，导致界面处发生机械互锁。因此，最终涂层厚度也相对较大。当使用硬不锈钢作为基底时，由于基底材料的高硬度而缺乏形成机械联锁的必要条件。此外，与Ti-Cu情况相比，界面边缘处的金属射流不太突出，界面接触面积也较小。因此，颗粒-基材结合强度和随之而来的涂层厚度相对较低。此外，还发现喷涂角度对粒子变形和涂层质量有显著影响。由于附加的切向动量，粒子的变形仅局限于一侧。此外，这种局部变形随着喷雾角的减小而变得越来越强烈。涂层厚度随斯帕伊角度的减小而减小，孔隙率随喷涂角度的减小而减小。
In this study, finite element analysis combined with experimental observation was conducted to clarify the effects of substrate hardness and spray angle on the deposition behavior of cold-sprayed Ti particles. It is found that metallurgical bonding is highly possible to occur between the Ti particle and Cu substrate due to the intensive metal jet at the rim of the interface which helps to remove the cracked oxides. Because metallurgical bonding and large interfacial contact area can guarantee high adhesion strength, the thick Ti coating is achieved after deposition on the Cu substrate. As for the soft Al substrate, the first layer Ti particles are embedded in and then trapped by the soft substrate material, which results in the occurrence of mechanical interlock at the interface. As a consequence, the final coating thickness is also relatively large. When using hard stainless steel as the substrate, the essential conditions for forming the mechanical interlock are lacked due to the high hardness of the substrate material. In addition, the metal jet at rim of the interface is less prominent and also the interfacial contact area is smaller in comparison with the Ti-Cu case. Therefore, the particle-substrate bonding strength and the consequent coating thickness are relatively low. Besides, it is also found that the particle deformation and coating quality are significantly affected by the spray angle. The deformation of the particle localizes at only one side due to the additional tangential momentum. Also, such localized deformation becomes increasingly intensive with decreasing the spray angle. Moreover, the coating thickness is found to reduce with the decrease in spay angle, but the coating porosity shows a reverse trend.