金属陶瓷涂层的固体粒子冲蚀磨损行为研究

发布时间：2018-03-05 12:00

本文选题：金属陶瓷涂层　切入点：冲蚀　出处：《北京石油化工学院》2015年硕士论文　论文类型：学位论文

【摘要】：固体颗粒的冲蚀是造成防护涂层失效或破坏的重要原因之一,目前针对其磨损机理和失效行为尚缺乏系统深入的研究。本文使用数值模拟与试验及理论分析相结合的方法,对Cr3C2-NiCr金属陶瓷涂层在固体粒子冲蚀下的磨损力学行为进行了研究,主要内容如下:(1)分析了冲蚀磨损机理及其主要影响因素。针对现有文献对于冲蚀过程数值模拟方法研究的不足,基于显式动力学理论,提出了冲蚀磨损过程的数值建模方法,并对仿真关键技术进行了深入研究。利用ANSYS/LS-DYNA建立了单颗粒冲蚀力学模型,分析了冲蚀过程中粒子运动和能量变化规律。通过分析单颗粒冲蚀条件下的仿真研究,并与现有文献试验数据对比,验证了建模方法的有效性。(2)提出了偏置建模法,构建了多固体颗粒冲蚀磨损的仿真模型,分别研究了涂层厚度、冲蚀粒子速度、冲蚀粒子大小等因素对金属陶瓷涂层的作用机制。结果表明:涂层厚度是影响冲蚀磨损的关键因素,实际工程应用中应制备合理的涂层厚度(大于100μm),以有效地保护基体材料;固体粒子侵蚀机制主要是由冲蚀粒子的动能决定,冲蚀磨损率随冲击速度的增大而增加;冲蚀粒子在40~60μm直径范围内涂层材料磨损率和等效应力最大,超过60μm后,其值基本不变。(3)制备了Cr3C2-NiCr金属陶瓷涂层试样,观察了涂层表面及截面的微区组织,并对涂层性能进行了分析。开展了不同冲蚀条件下(冲蚀压力、冲蚀角度、冲蚀粒子尺寸和冲蚀温度)的试验研究,结果表明涂层材料的最大体积冲蚀磨损率出现在60°冲角范围内,涂层同时表现出脆、塑性冲蚀失效机制。其它各影响因素得到的试验结果与仿真规律大致吻合,这一方面验证了仿真模型的正确性,另一方面也为涂层的合理设计及抗磨损性能研究提供一定的理论指导。(4)针对现有高温冲蚀试验装置的不足,设计了可调角度的高温固体粒子冲蚀磨损测试装置,完成了主要零部件的设计,为后续高温条件下固体粒子冲蚀磨损行为研究提供了更高效的测试手段和方法。
[Abstract]:The erosion of solid particles is one of the important reasons for the failure or failure of protective coatings. At present, the wear mechanism and failure behavior of solid particles have not been studied systematically and deeply. In this paper, the method of combining numerical simulation with test and theoretical analysis is used. The wear mechanical behavior of Cr3C2-NiCr cermet coating under solid particle erosion was studied. The main contents are as follows: (1) the erosion wear mechanism and its main influencing factors are analyzed. The numerical modeling method of erosion process is proposed based on explicit dynamics theory. The key technology of simulation is deeply studied. The mechanical model of single particle erosion is established by ANSYS/LS-DYNA, and the law of particle motion and energy change in the process of erosion is analyzed. By analyzing the simulation research under the condition of single particle erosion, Comparing with the existing experimental data, the effectiveness of the modeling method is verified. (2) the bias modeling method is proposed, and the simulation model of erosion wear of multi-solid particles is constructed. The thickness of coating and the velocity of erosion particles are studied, respectively. The effect mechanism of erosion particle size on cermet coating. The results show that the thickness of the coating is the key factor affecting the erosion wear, and a reasonable coating thickness (more than 100 渭 m) should be prepared in practical engineering to protect the substrate material effectively. The erosion mechanism of solid particles is mainly determined by the kinetic energy of the erosion particles, and the erosion wear rate increases with the increase of the impact velocity, and the wear rate and equivalent stress of the coating materials are the largest in the range of 40 ~ 60 渭 m in diameter, when the erosion rate exceeds 60 渭 m. Cr3C2-NiCr cermet coating samples were prepared, the microstructure of the coating surface and section were observed, and the properties of the coating were analyzed. Under different erosion conditions (erosion pressure, erosion angle, erosion angle), The results show that the maximum volume erosion wear rate of the coating material appears in the range of 60 掳angle of attack, and the coating exhibits brittleness at the same time. The failure mechanism of plastic erosion. The experimental results obtained by other factors are in good agreement with the simulation law. On the one hand, the correctness of the simulation model is verified. On the other hand, it also provides some theoretical guidance for the reasonable design of coating and the study of wear resistance. (4) aiming at the deficiency of the existing high temperature erosion test equipment, a high temperature solid particle erosion wear testing device with adjustable angle is designed. The design of the main components is completed, which provides a more efficient test method for the study of erosion wear behavior of solid particles at high temperature.
【学位授予单位】：北京石油化工学院
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TG174.4

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