The Effect of Machined Surface Conditioning on the Coating Interface of High Velocity Oxygen Fuel (HVOF) Sprayed Coating
The Effect of Machined Surface Conditioning on the Coating Interface of High Velocity Oxygen Fuel (HVOF) Sprayed Coating
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DOI：
10.3390/jmmp3030079
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发表时间：
2019-09
影响因子：
3.2
通讯作者：
Meik Tilger;D. Biermann;M. Abdulgader;W. Tillmann
中科院分区：
文献类型：
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作者：
Meik Tilger;D. Biermann;M. Abdulgader;W. Tillmann
粗糙化基材表面是热喷涂涂层的基本要求。在这方面，喷砂已成为一种易于使用的表面处理程序。所获得的粗糙度的质量取决于喷砂材料的条件、调整的参数以及工艺执行的类型（手动或机械）。这些先决条件限制了所获得的粗糙度的再现性。喷砂会产生残余压应力，也可能导致粗糙表面中包含砂粒和缺口，这会影响涂层的界面性能以及涂层部件的弯曲强度。因此，粗糙表面的硬度起着重要作用。然而，为了可靠地避免这些影响，可以使用微精加工作为替代方案，以产生均匀粗糙的基底表面，控制诱导的残余应力，并增加再现性。此外，粗糙化表面图案可以在待涂覆部件的切屑形成过程中产生。利用适当的机械加工工艺和参数组合应导致所需的表面图案，从而提高涂层附着力和涂层部件的抗弯强度。残余应力和表面粗糙度对涂层附着力和涂层零件的使用寿命有重要影响。本文旨在分析，作为第一步，车削和微精加工的轴承钢100Cr6（AISI 52100）的表面处理的效果。研究结果表明，微精加工和喷砂处理后的表面与超音速火焰喷涂涂层的结合力和界面结合力有较大的差异。表面处理通过诱导残余应力和消除粘附缺陷起着决定性作用。
Roughening the substrate surface is essential for thermal sprayed coatings. In this regard, sandblasting has established itself as an easy to use surface conditioning procedure. The quality of the obtained roughness depends on the conditions of the sandblasting material, adjusted parameters, and the kind of the process execution (manual or mechanical). These preconditions limit the reproducibility of the roughness obtained. Sandblasting causes residual compressive stress and may also lead to the inclusion of sand particles and notches in the roughened surface, which affects the interfacial properties of the coating, as well as the flexural strength of the coated parts. The hardness of the roughened surface plays, thereby, an important role. However, in order to reliably avoid these effects, microfinishing can be used as an alternative to generate a homogenous roughened substrate surface, control the induced residual stresses, and increase the reproducibility. In addition, the roughened surface pattern can be produced during the chip forming process of the to-be-coated parts. The utilization of the appropriate combination of machining processes and parameters should lead to the required surface pattern and thus to an enhanced coating adhesion and flexural strength of the coated part. The induced residual stresses and the quality of the obtained surface roughness have a significant influence on the coating adhesion and the lifespan of the coated parts. This paper aims to analyze, as a first step, the effect of the turning and microfinishing on the surface conditioning of the bearing steel 100Cr6 (AISI 52100). The investigation concludes by comparing the microfinished with the sandblasted surfaces with regard to the interface to and the adhesion of the WC–Co high velocity oxygen fuel (HVOF) sprayed coatings on them. Surface conditioning plays a decisive role by the induced residual stresses and the elimination of adhesion defects.