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包覆涂层钎焊接头微观组织及界面反应研究

时间:2022-11-20 09:00来源:毕业论文
钎焊涂层组织为WC相及粘结相组成的非均匀结构,涂层致密无气孔。随着钎焊温度的升高,基体与涂层发生的冶金反应加剧

摘要柔性“金属贴布”是近20几年发展起来的一种新型金属表面改性技术。论文对金属布的制作、组织性能及成分进行分析。采用轧制的方法制备了WC含量为20%,BNi-2含量为80%的“金属布”,将该布剪切并铺展于碳钢表面进行真空钎焊,基体与涂层发生界面反应。利用金相显微镜、扫描电子显微镜对试样截面及表面组织进行观察和成分分析。研究了在相同配方下不同钎焊温度对钎焊涂层组织和性能的影响。研究结果表明:钎焊涂层组织为WC相及粘结相组成的非均匀结构,涂层致密无气孔。随着钎焊温度的升高,基体与涂层发生的冶金反应加剧。通过对试样进行硬度测试,随着钎焊温度的提高钎焊涂层的硬度下降,当温度升高到一定程度时,其硬度维持一定值,不会发生大幅度变化。86151

毕业论文关键词:钎焊涂层;微观组织;钎焊温度;界面反应

Abstract Flexible metal "Plaster" is a new type of metal surface modification technology developed in recent 20 years。 In this paper, the production, the structure and the composition of the metal cloth are analyzed。 The method of rolling by same components of “metal cloth”, the cloth cutting and spreading on the surface of carbon steel by vacuum brazing, coating and the substrate occurred interfacial reaction。 Optical microscope and scanning electron microscope were used to observe and analyze the microstructure of specimen section。 The effects of brazing temperature on the microstructure and properties of the coating were studied under the same formulation。 The results show that the microstructure of the WC phase and the bonded phase is not uniform, and the coating is compact and free of pores。 Brazing coating in the brazing temperature is different, will has important effect on the microstructure and properties of coating, low brazing temperature is not conducive to the diffusion of solder to WC particles, high brazing temperature easily in WC with BNi-2 filler metal interface was born into a brittle phase。 By testing the hardness of the sample, the hardness of the brazing coating decreased with the increasing of brazing temperature。 When the temperature was increased to a certain degree, the hardness of the sample was maintained at a certain value。 The microstructure and element composition of the sample under different temperature were obtained by metallographic microscope observation and scanning electron microscope。

Keywords: Brazing coating structure; Microstructure; Brazing temperature; Interface reaction

目  录

第一章 绪论 1

1。1 课题研究背景 1

1。2 钎焊涂层的特点 2

1。3 国内外钎焊涂层研究成果 4

1。4 论文的研究内容及意义 5

第二章 试验材料设备及方法 7

2。1 试验材料 7

2。2 试验设备及方法 7

2。2。1 真空钎焊试验 7

2。2。2 制备金属布 8

2。2。3 试样加工处理 8

2。2。4 硬度测试方法 9

2。2。5 合金金相组织观察 10

2。2。6 扫描电镜显微组织及断口观察 10

第三章 试验结果与讨论 12

3。1 钎焊式样宏观形貌 12

3。2 钎焊涂层微观组织形貌 包覆涂层钎焊接头微观组织及界面反应研究:http://www.youerw.com/cailiao/lunwen_102218.html

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