等离子喷涂Ni基WC金属陶瓷涂层的激光重熔工艺研究

发布时间：2018-09-08 12:29

【摘要】：随着现代工业的迅猛发展,人们对机器上机械零部件的要求越来越高.其使用的环境也变得多样化,许多零部件必须在高温、腐蚀性气体等环境中工作。由于目前开发的金属材料,在满足适用的前提下性价比很低。现代工业急需研制出新材料以满足使用要求。在传统材料中,陶瓷涂层具备诸多优点。如果将陶瓷涂覆在金属的基体上形成新的复合材料,不但综合了陶瓷与金属的优点,而且两种材料的高韧性、高导电性互为补充,因而受到了广泛的重视。本文以45钢为研究对象,采用等离子喷涂与激光重熔复合工艺制备Ni基WC复合涂层,基于ANSYS平台建立等离子喷涂与激光重熔过程温度场应力场有限元模型,分析了各种工艺参数下温度场的演化规律,研究了该涂层的显微组织与力学性能。论文的主要研究成果:(1).设计ANSYS有限元分析模型,实现了对等离子喷涂涂层逐层进行热结构耦合计算,得出了温度场和应力场的分布结果;对激光重熔涂层建立有限元分析模型,研究了不同激光重熔工艺参数下,等离子喷涂Ni/WC涂层温度场、应力场的变化情况。为后续实验工艺参数优化提供了理论依据。.(2)采用SEM、XRD等检测设备分析了等离子喷涂与激光重熔Ni/WC复合涂层的微观组织与相组成,结果表明:等离子喷涂层呈典型层状结构,涂层与基体结合方式为机械结合,经激光重熔处理后,涂层表面光滑平整,结合方式由机械结合转变为冶金结合。WC颗粒在高温发生分解,C元素与Cr、Fe等元素充分反应后生成新的硬质相,进一步提高了涂层硬度与耐磨性能。
[Abstract]:With the rapid development of modern industry, people are demanding more and more machine parts. The use of the environment has also become diversified, many parts must work in high temperature, corrosive gases and other environments. Because of the metal materials developed at present, the performance-price ratio is very low under the condition of satisfying the applicable condition. Modern industry is in urgent need of developing new materials to meet the operational requirements. Ceramic coatings have many advantages in traditional materials. If the ceramic is coated on the metal matrix to form a new composite material, not only the advantages of ceramics and metals are integrated, but also the high toughness and high conductivity of the two materials complement each other, so they are paid more and more attention. In this paper, Ni based WC composite coating was prepared by plasma spraying and laser remelting process, and the finite element model of temperature field stress field in plasma spraying and laser remelting process was established based on ANSYS platform. The evolution law of temperature field under various technological parameters was analyzed, and the microstructure and mechanical properties of the coating were studied. The main research results are as follows: (1). The ANSYS finite element analysis model is designed, the thermal structure coupling calculation of plasma sprayed coating layer by layer is realized, the distribution results of temperature field and stress field are obtained, and the finite element analysis model of laser remelting coating is established. The temperature field and stress field of plasma sprayed Ni/WC coating were studied under different laser remelting process parameters. (2) the microstructure and phase composition of plasma sprayed and laser remelted Ni/WC composite coatings are analyzed by means of SEM,XRD and other testing equipment. The results show that the plasma sprayed coating has a typical layered structure. After laser remelting, the coating surface is smooth and smooth. The bonding mode was changed from mechanical bonding to metallurgical bonding. After decomposition of C element with Cr,Fe element at high temperature, a new hard phase was formed, which further improved the hardness and wear resistance of the coating.
【学位授予单位】：江西理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TG174.4

【参考文献】