Water-lubricated tribological behavior of WC-Ni coatings deposited by off-angle HVOF spraying
Water-lubricated tribological behavior of WC-Ni coatings deposited by off-angle HVOF spraying
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斜角 HVOF 喷涂沉积的 WC-Ni 涂层的水润滑摩擦学行为
DOI：
10.1016/j.surfcoat.2016.11.026
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发表时间：
2017-01
影响因子：
5.4
通讯作者：
Lei M. K.
中科院分区：
文献类型：
--
作者：
Du P. C.;Zhu X. P.;Meng Y.;Feng H.;Wang Q. F.;Lei M. K.
斜角热喷涂涂层通常在涂层特征和特性（例如密度、显微硬度和/或韧性）方面存在显著的退化。先前针对不同的热喷涂技术提出了临界喷涂角，例如HVOF为45°、电弧喷涂为60°、等离子喷涂为50°或45°，主要基于以法向角为基准的退化程度。在这项研究中，偏角超音速火焰喷涂的WC-Ni涂层的可行性澄清直接在水润滑下的磨损性能，因为报道的磨损试验结果似乎是有争议的。结果表明，喷涂角度从90°减小到30°时，涂层孔隙率几乎增加了3倍，但孔隙率上限在3%以内，WC相保留率的最大变化约为13.6%，显微硬度和弹性模量的最大变化约为11.7%，压痕断裂韧性的最大变化约为26.4%。在10− 4-10− 5 mm 3/Nm范围内，与文献报道的干磨粒磨损试验结果相比，超音速火焰喷涂WC-Co涂层在30°喷涂角下的比磨损率几乎是90°喷涂角下的2倍，我们的水润滑磨损试验表明，WC-10 Ni涂层的比磨损率非常低，低于10− 7 mm 3/Nm，最大变化约为30%，相对于正常喷雾角的喷雾角。在30°和45°角下，斜角喷涂涂层的摩擦系数显著降低。摩擦学性能的改善主要归因于较高的孔隙率和良好分散的微孔有利于更好的水润滑，以及由于将孔隙率控制在一定范围内而基本保留了斜角涂层的机械性能。喷涂角度小于30°的WC-Ni涂层由于改善了流体润滑特性而适用于摩擦学应用。
The off-angle thermally sprayed coatings generally present noticeable degradation in coating feature and characteristic, such as density, microhardness and/or toughness. A critical spray angle was previously suggested for different thermal spray techniques, e.g. HVOF of 45°, wire arc spraying of 60°, plasma spraying of 50° or 45°, primarily based on degree of the degradation benchmarked on that of normal angle. In this study, the feasibility of off-angle HVOF spraying of WC-Ni coatings is clarified directly by wear performance under water lubrication, since reported wear test results seem to be controversial. It is found that, the coating porosity is almost tripled with an upper limit within 3% as reducing the spray angle from 90° to 30°, while the maximum variation in the WC phase retention is about 13.6%, and about 11.7% in both microhardness and elastic modulus, and about 26.4% in indentation fracture toughness, respectively. As compared to a reported dry abrasive wear test showing that specific wear rate of HVOF WC-Co coatings at a spray angle of 30° was nearly doubled to that of 90° within 10− 4–10− 5mm3/Nm, our water-lubricated wear test shows a comparably low specific wear rate below 10− 7mm3/Nm with about 30% maximum variation for WC-10Ni coatings off-angle sprayed with respect to that of normal spray angle. A notable reduction in friction coefficient is confirmed for off-angle sprayed coatings at 30° and 45°. The improved tribological behavior is mainly attributed to the higher porosity with well-dispersed micro-pores facilitating a better water lubrication, as well as the mostly retained mechanical properties of off-angle coatings due to controlled porosity in a certain range. The off-angle sprayed WC-Ni coatings down to the spray angle of 30° are applicable in tribological applications due to improved fluid lubricating characteristic.
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DOI：
--
发表时间：
1995
期刊：
--
影响因子：
--
作者：
C. M. Hacket
通讯作者：
C. M. Hacket
影响因子：
5.4
作者：
G. Espie;A. Denoirjean;P. Fauchais;J. Labbe;J. Dubský;O. Schneeweiss;K. Voleník
通讯作者：
G. Espie;A. Denoirjean;P. Fauchais;J. Labbe;J. Dubský;O. Schneeweiss;K. Voleník
影响因子：
3.1
作者：
C. Hackett;G. Settles;J. Miller
通讯作者：
C. Hackett;G. Settles;J. Miller
影响因子：
3.1
作者：
R. Neiser;Mark F. Smith;R. Dykhuizen
通讯作者：
R. Neiser;Mark F. Smith;R. Dykhuizen
影响因子：
3.1
作者：
Yikai Chen;Y. Tan;Silvia Tessarini;S. Sampath
通讯作者：
Yikai Chen;Y. Tan;Silvia Tessarini;S. Sampath