摘要活塞杆是液压缸动力输出的执行部件，由于经常暴露在外部环境下往复运动，其表面很容易产生磨损和腐蚀。目前活塞杆表面防护的传统工艺是在表面镀铬，但镀铬工艺严重污染环境，其废水和废气严重致癌，对人体危害较大。鉴于此，本课题拟采用一种新型工艺——等离子喷涂技术对活塞杆表面进行防护，以期制备出耐蚀、耐磨的高性能涂层并对其各性能加以研究。

本文采用NiCrBSi涂层材料对2Cr13不锈钢活塞杆表面进行等离子喷涂，对制备好的涂层进行重熔处理。借助SEM、EDS和XRD对喷涂态涂层和重熔态涂层的微观组织结构、形貌及涂层成分进行分析，通过测试对比上述涂层结合强度、显微硬度、孔隙率和耐腐蚀性来综合评定涂层的性能。87005

试验研究结果表明：喷涂态涂层与基体以机械结合方式为主，涂层存在少量的孔洞、裂纹等缺陷。经过重熔后的涂层，涂层结构更加均匀、致密，涂层结合强度也略高于喷涂态涂层。此外，孔隙率还大大降低，不到喷涂态的一半。在显微硬度方面，重熔态涂层的硬度也明显高于喷涂态。经过电化学试验测定，重熔态涂层腐蚀电位和钝化区更高，腐蚀电流更低，其耐蚀性能更加明显。

毕业论文关键词：大气等离子喷涂；活塞杆；防护涂层；涂层性能

Abstract Piston rod is the executive component of the power output of the hydraulic cylinder, because it is often exposed to the reciprocating motion of the external environment, its surface is easy to abrasion and corrosion。 In view of this, this subject is to use a new technology -- plasma spraying technology on the surface of the piston rod to protect, in order to prepare the corrosion resistance, wear resistance of high performance coating and its performance to be studied。

This paper adopts NiCrBSi coating material for 2Cr13 stainless steel piston rod surface by plasma spraying, and remelting processing for the coating 。By means of SEM, EDS and XRD, the microstructure of the coating and the laser remelted coating of spray, morphology and composition of coating were analyzed, through the contrast test of the coating bonding strength, micro hardness, porosity and resistance to corrosive to comprehensive evaluation of coating performance。

The experimental results show that the coating and the substrate are mainly mechanical bonding, the coating has a small amount of holes, cracks and other defects。 After remelting coating, the coating structure is more uniform and dense, and the bonding strength of the coating is slightly higher than that of the coating。 In addition, the porosity is lower, less than half of the spraying state。 In the micro hardness, the hardness of the coating is significantly higher than that of the coating。 After electrochemical tests, the corrosion potential and passivation zone are higher, and the corrosion current is lower, and the corrosion resistance of the coating is more obvious。

Keywords: atmospheric plasma spraying；piston rod；protective coating； coating properties

目  录

第一章  绪论 1

1。1 引言 1

1。2 等离子喷涂技术概述 2

1。2。1 等离子喷涂基本原理 2

1。2。2 等离子喷涂涂层形成过程 3

1。2。3 等离子喷涂的特点 4

1。2。4 影响等离子涂层质量的主要工艺参数 4

1。2。5 等离子喷涂涂层的应用 6

1。3 液压缸活塞杆的失效形式