摘要： DD417G合金是密度最小的单晶高温合金，不含W、Ta、Nb、Hf、Re等贵重金属。本文利用X射线衍射分析、扫描电镜和能谱分析等分析手段对DD417G合金在810℃和910℃的组织与抗氧化性能进行了初步地研究。实验结果表明：DD417G合金经高温氧化后表面形成出现了大量细小而致密的氧化物颗粒，成了具有一定厚度连续致密的氧化膜，随着加热温度与时间的增加，氧化膜的厚度也逐渐增，更多的元素也从合金内析出并在样品表面形成氧化物颗粒；表面氧化膜的外层主要成分是Cr2O3、内层主要成分是Al2O3。合金在910℃ 氧化10小时后，合金表面氧化膜截面厚度且无剥落现象，由此可以证明该合金在高温环境中存在较好的抗氧化能力。62141

毕业论文关键词： DD417G合金；高温氧化；合金元素；镍基单晶合金

Research on high temperature oxidation behavior of alloys DD417G

Abstract: DD417G alloy is the least dense crystal superalloy, excluding W, Ta, Nb, Hf, Re and other precious metals. In this paper, the use of X-ray diffraction analysis, scanning electron microscopy and energy spectrum analysis means for analyzing DD417G alloy microstructure and oxidation resistance at 810 ℃ and 910 ℃ conducted a preliminary study. The results showed that: DD417G alloy formed on the surface by high temperature oxidation appeared a large number of small, dense oxide particles, an oxide film having a certain thickness became continuous and compact, with the increase of heating temperature and time, the thickness of the oxide film is also gradually increasing , more elements are precipitated from the surface of the alloy and oxide particles in the sample; main component of the outer surface of the oxide film is Cr2O3, the main component of the inner layer is Al2O3. Alloy oxidation at 910 ℃ for 10 hours, the alloy surface oxide film-sectional thickness and no flaking, which can prove the existence of the alloy good oxidation resistance in high temperature environments.

Keywords: DD417G alloy; high temperature oxidation; alloying elements; single crystal super alloy

目　录

1 绪论 1

1.1 高温合金的概述 1

1.1.1 国外高温合金发展简史 1

1.1.2 我国高温合金发展历程 2

1.1.3 高温合金的性能特征及其用途 3

1.1.4 高温合金分类和牌号的表示法 4

1.2 单晶高温合金概述 5

1.2.1 单晶高温合金发展现状 5

1.2.2 单晶高温合金成分发展的主要特点 6

1.2.3 单晶高温合金主要强化元素的作用 6

1.2.4 Cr含量对单晶高温合金显微组织和力学性能的影响 8

1.3 金属氧化的概述 8

1.3.1 氧化物的结构 8

1.3.2 氧化物的生长 8

1.3.3 氧化物的应力