Abstract This paper presents a two-dimensional (2D) plane strain finite element model to simulate fretting wear in composite cermet coating. The coating considered in this investigation is High Velocity Oxy-Fuel (HVOF) sprayed Cr3C2 – NiCr with 55% volume fraction of Cr3C2. The material microstructure is modelled using Voronoi tessellations with a log-normal variation of grain size. Moreover, the individual phases of the material in the coating were assigned randomly to resemble the microstructure from an actual SEM micrograph. The ceramic carbide phase is orthorhombic and the cubic matrix possesses a high anisotropy index. As a result, each grain was modeled with random orientation to account for material anisotropy. The RVE dimensions were chosen such that its elastic response represented the overall response of a poly-aggregate. In order to simulate debonding of the ceramic carbide phase from the matrix, cohesive elements were used at the grain boundaries. Damage mechanics was stused to model degradation of cohesive elements resulting from repeated fretting cycles. A grain deletion algorithm was developed to simulate removal of material from fretting wear. The crack patterns predicted from the model match closely with the patterns observed in experimental studies on wear of HVOF Cr3C2 – NiCr coating. The model also predicts carbide pullout, a major damage mechanism in HVOF Cr3C2 – NiCr coating subjected to wear. Experiments were also conducted to evaluate and corroborate the wear rate of HVOF Cr3C2 – NiCr coating. The wear rate from the model matches closely with experiments at a constant load and displacement amplitude. The results from the model were then extended to obtain a fretting wear map under a combination of various loads and displacement amplitudes.

中文翻译：

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各向异性复合涂层微动磨损的有限元建模：应用于 HVOF Cr3C2 – NiCr 涂层

摘要 本文提出了一种二维 (2D) 平面应变有限元模型来模拟复合金属陶瓷涂层的微动磨损。本研究中考虑的涂层是高速氧燃料 (HVOF) 喷涂的 Cr3C2 – NiCr，Cr3C2 的体积分数为 55%。材料微观结构使用 Voronoi 镶嵌法建模，晶粒尺寸呈对数正态变化。此外，涂层中材料的各个相被随机分配以类似于来自实际 SEM 显微照片的微观结构。陶瓷碳化物相是正交相，立方基体具有高各向异性指数。因此，每个晶粒都以随机方向建模，以说明材料的各向异性。选择 RVE 尺寸，使其弹性响应代表聚合体的整体响应。为了模拟陶瓷碳化物相从基体上的剥离，在晶界处使用了内聚元素。损伤力学被用来模拟由重复微动循环引起的粘性元件的退化。开发了一种晶粒删除算法来模拟从微动磨损中去除材料。从模型预测的裂纹模式与在 HVOF Cr3C2 – NiCr 涂层磨损实验研究中观察到的模式密切匹配。该模型还预测了碳化物拉出，这是 HVOF Cr3C2 – NiCr 涂层磨损的主要损伤机制。还进行了实验以评估和证实 HVOF Cr3C2 – NiCr 涂层的磨损率。模型的磨损率与恒定载荷和位移幅度下的实验密切匹配。