点击次数：

论文类型：期刊论文

发表时间：2014-06-01

发表刊物：SURFACE ENGINEERING

收录刊物：SCIE、EI

卷号：30

期号：6

页面范围：443-450

ISSN号：0267-0844

关键字：Cold spray; Computational fluid dynamics; Numerical simulation; Carrier gas; Coating; Preheating

摘要：Carrier gas is known as the medium to inject the cold sprayed powders into the main driving flow inside the nozzle. Hence, the properties and conditions of carrier gas should be of great importance to the particle motion behaviour and then particle deposition process. In this study, the effect of carrier gas temperature on the particle acceleration and deposition in cold spray process was investigated by both numerical and experimental methods. It is found that the supersonic driving gas flow and the consequent particle acceleration behaviour are significantly influenced by the carrier gas temperature, more specifically, higher carrier gas temperature results in higher particle impact velocity. In addition, because the carrier gas has additional heating effect on the powder particles before injection, the final impact temperature also increases with the carrier gas temperature, which leads to the reduction in the critical velocity. The increase in particle impact velocity and reduction in critical velocity enable the deposition efficiency and coating bonding strength to significantly improve as the carrier gas temperature increases. The particle impact velocity is found to be more influential than critical velocity reduction.