In this paper, we examine the correlation between thermal spray process parameters that affect the deposition rate and the residual stress buildup in HVOF metallic and cermet coatings. Parameters of interest including feed-rate, raster speed, and substrate temperature (controlled via external cooling means) were evaluated in the context of their effect on the stress evolution in gas fuel HVOF-sprayed coatings. The process variables investigated are intended to change the deposition rate and subsequently the local deposition temperature (TLD) at the location of impact. The residual stress during the deposition tends to be more tensile with increased TLD, and this tendency is more significant when the change in TLD is produced by the feed rate. Compressive stresses result for lower TLD due to dominance of the peening effect. A systematic study of these effects was conducted for gas fuel HVOF-sprayed Ni- and WC-12%wt.Co-coatings. The Ni-coatings represent the family of ductile metallic materials, whereas the WC-12%wt.Co-coatings represent the behavior of hard cermets. Both materials develop compressive stress at low TLD and change into tensile stress at high TLD by manipulation of deposition rate parameters. Extensions to other materials and HVOF processes are also presented to support the analysis.

中文翻译：

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沉积速率和沉积温度对 HVOF 喷涂涂层残余应力的影响

在本文中，我们研究了影响沉积速率的热喷涂工艺参数与 HV​​OF 金属和金属陶瓷涂层中残余应力积累之间的相关性。感兴趣的参数包括进给速率、光栅速度和基板温度（通过外部冷却装置控制）在它们对气体燃料 HVOF 喷涂涂层应力演变的影响的背景下进行了评估。所研究的工艺变量旨在改变沉积速率，随后改变撞击位置的局部沉积温度 (TLD)。随着TLD的增加，沉积过程中的残余应力趋于更大，当TLD的变化由进料速率产生时，这种趋势更加显着。由于喷丸效应占主导地位，压缩应力导致较低的 TLD。对气体燃料 HVOF 喷涂的 Ni 和 WC-12%wt.Co 涂层进行了这些影响的系统研究。Ni 涂层代表韧性金属材料系列，而 WC-12%wt.Co 涂层代表硬金属陶瓷的行为。两种材料在低 TLD 时都会产生压应力，并通过控制沉积速率参数在高 TLD 时变成拉伸应力。还介绍了对其他材料和 HVOF 工艺的扩展以支持分析。