摘要钛铝基合金在高温工作条件下，材料的抗氧化性能不足。当使用温度高于850℃时，合金的抗氧化性能迅速降低。本文利用大气等离子喷涂工艺(APS)，在钛铝基合金Ti-48Al-2Cr-2Nb表面制备抗高温氧化涂层，涂层结构为NiCoCrAl/ZrO2复合涂层。以涂层结合强度为指标，开展正交实验优化喷涂工艺参数，并采用全自动显微硬度计测定涂层硬度。86500

试验结果表明，当打底层工艺参数为：喷涂距离110mm、喷涂电流750A、喷涂电压45V、主气流量60psi、送粉量0。85r/min，陶瓷层工艺参数为：喷涂距离110mm、喷涂电流850A、喷涂电压50V，主气流量60psi、送粉量1。2/min、喷涂4次时，NiCoCrAl/ZrO2复合涂层得到优化，结合强度达55。80MPa。

本文采用抗热震试验和电化学试验，对比不同材料及工艺的涂层抗热震性能和耐蚀性差异。陶瓷涂层抗热震性较好，20℃~800℃热震试验中，裂纹起源于母材靠近涂层处。基体材料耐蚀性能远高于涂层材料，而打底层与陶瓷涂层耐蚀性则相近。改变涂层喷涂次数(即涂层厚度)对涂层的耐蚀性影响较小，而涂层喷后利用等离子焰空扫则会显著提高涂层的耐蚀性。

毕业论文关键词：钛铝基合金；APS；陶瓷涂层；抗高温氧化

Abstract Under high temperature working conditions, the oxidation resistance of TiAl based alloy is insufficient。 When the temperature is higher than 850, the oxidation resistance of the alloy decreases rapidly。 In this paper, the high temperature oxidation coating was prepared on the surface of titanium aluminum base alloy Ti-48Al-2Cr-2Nb by atmospheric plasma spraying technology (APS), and the coating structure was NiCoCrAl/ZrO2 composite coating。 The orthogonal experiment was carried out to optimize the spraying process parameters, and the coating hardness was measured by the full automatic micro hardness tester。

Test results show that when the bottom process parameters are: spraying distance 110mm, spraying current 750A, spraying voltage 45V, main gas flow 60psi, powder feeding amount of 0。85r/min, the process parameters of ceramic layer: spraying distance of 110, current 850A spray, spray voltage 50V, primary gas flow 60psi, send volume fly 1。2/min, spray 4 times, NiCoCrAl/ZrO2 composite coatings are optimized, the bonding strength of 55。80MPa。

In this paper, thermal shock test and electrochemical test were used to compare the thermal shock resistance and corrosion resistance of different materials and processes。 The thermal shock resistance of ceramic coatings is better than that of 20 C ~800 C, the crack originated from the base material near the coating。 The corrosion resistance of the base material is much higher than that of the coating material, and the bottom layer is similar to that of the ceramic coating。 The influence of the coating thickness on the corrosion resistance of the coating was small, and the corrosion resistance of the coating was significantly improved after the coating sprayed with plasma flame。

Keywords: TiAl-based alloy; APS; ceramic coating; resistance to high temperature oxidation

目  录

第一章  绪论 1

1。1 选题背景和意义 1

1。2 等离子喷涂技术的发展 1

1。3 等离子喷涂原理及特点 3

1。4 钛铝基合金的特点及应用 4

1。4。1 钛铝基合金的优点 4

1。4。2 钛铝基合金的不足 4

1。5 钛铝基合金的高温氧化防护 4

1。5。1 合金化