Wear behaviour of flame sprayed NiCrBSi coating remelted by flame or by laser
Wear behaviour of flame sprayed NiCrBSi coating remelted by flame or by laser
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DOI：
10.1016/j.wear.2006.05.009
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发表时间：
2007-02-04
期刊：
影响因子：
5
通讯作者：
Rodriguez, E.
中科院分区：
文献类型：
--
作者：
Gonzalez, R.;Cadenas, M.;Rodriguez, E.
火焰喷涂涂层因成本低和工艺简单而在工业中广泛应用。然而，高孔隙率以及与基体的附着力差意味着质量不佳，不过通过使用一种通常涉及氧乙炔火焰的技术对涂层进行重熔，质量可以得到改善。接下来的研究试图评估一种激光技术，作为对火焰喷涂层更传统的火焰重熔的替代方法，采用灰铸铁（DIN GG30）作为基体，一种NiCrBSi合金作为涂层材料。通过激光重熔获得的涂层呈现出几乎无孔隙的微观结构，且与基体的附着力良好。火焰重熔过程中对工艺参数的有限控制在某些情况下导致涂层全厚度未完全熔化。两种情况下重熔涂层的硬度非常相似，其数值略低于火焰喷涂层。然后在不同载荷（30 - 100 N）和滑动速度（0.65 - 2.62 m/s）下的干滑动磨损试验（环 - 块试验）中对两种涂层类型的摩擦学行为进行了比较。计算了两种涂层的磨损率和磨损率系数k（mm³/Nm）。未发现两种涂层在磨损性能上有显著差异。在较高试验载荷下观察到以粘着为主要成分的严重磨损状况。在较低试验速度下，主要的磨损机制是氧化。（c）2006 Elsevier B.V. 保留所有权利。
Flame spray coatings are widely used in industry because of low cost and process simplicity. However, high porosity and poor adherence to the substrate means that quality is poor, though it can nevertheless be improved by subjecting coatings to a remelting using a technique that usually involves an oxyacetylene flame. The study that follows is an attempt to evaluate a laser technique as an alternative to the more traditional flame remelting of flame spray layers, using grey cast iron (DIN GG30) as the substrate and a NiCrBSi alloy as the coating material. Coatings obtained by laser remelting exhibited a practically pore-free microstructure with good adherence to the substrate. The limited control of process parameters during flame remelting led in some cases to incomplete melting of the full thickness of the layers. Hardness of the remelted coatings was very similar in both cases, with values that were slightly lower than for flame-spray layers. The tribological behaviour of both coating types was then compared in dry sliding wear tests (block-on-ring tests) at various loads (30-100 N) and sliding speeds (0.65-2.62 m/s). Both coatings wear rates and wear rate coefficients k (mm(3)/Nm) were calculated. No significant differences in wear performance between the two coatings were found. A severe wear regime with adhesion as the principal component was observed at the higher test loads. The predominant wear mechanism at the lower test velocities was oxidation. (c) 2006 Elsevier B.V. All rights reserved.