稀土元素Hf,Ho对NiAl合金高温氧化行为的影响
毕业论文关键词：稀土元素；高温合金; NiAl；金属氧化
Rare earth elements of Hf, Ho to leicester and high-temperature oxidation behavior of alloy
Abstract: NiAl has many excellent properties, it studied the biggest interest is focused on the use of advanced aircraft engine high temperature structure parts. Compared with Ni based high temperature alloy, NiAl and has many outstanding advantages, such as a higher melting point, low density, good thermal conductivity, excellent oxidation resistance, etc., as a potential alternative materials, high temperature alloy in received special attention in the research of new materials, and in order to improve the high temperature mechanical properties of NiAl and joined the Cr, Mo, Hf, Ho, such as alloy elements, the microstructure and property has changed. The Hf,Ho to alloy high temperature oxidation performance have very important influence, its comprehensive effect mechanism is more complex. This topic mainly the leicester and eutectic alloy was studied at 800 ℃, 900 ℃ high temperature oxidation behavior of air and oxidation mechanism, the results show that the NiAl - Cr (Mo) - Hf - Ho alloy surface after the high temperature oxidation for Al2O3, Cr2O3, HfO2 composite oxide film, the addition of rare earth elements, Hf, Ho improves its outer oxide film adhesion, improve the oxidation resistance of alloy.
Key Words: rare earth element；high temperature alloy；NiAl；metal oxidation；
目录
摘要 i
Abstract i
目录 iii
1 绪论 1
1.1 高温合金 1
1.1.1 高温合金的发展概况 1
1.2 高温合金的分类 1
1.3 提高高温合金性能的途径和方法 2
1.3.1 结构强化 2
1.4 高温合金的制备工艺 4
1.4.1 高温合金的电弧炉冶炼 4
1.4.2 感应炉冶炼 4
1.4.3 真空感应炉冶炼 4
1.4.4 真空自耗炉重熔 4
1.4.5 高温合金的电渣炉重熔 4
1.4.6 高温合金的压力加工 4
1.4.7 高温合金涡轮盘的热加工 4
1.4.8 高温合金的熔模精密铸造 4
1.4.9 高温合金的热处理 5
1.4.10 高温合金的焊接 5
1.5 NIAL金属间化合物 5
1.5.1 NiAl基金属间化合物的概述 5
1.5.2 NiAl的物理性质 5
1.5.3 NiAl的化学性能 6
1.6 金属的高温氧化 6
1.6.1 金属初期氧化机理 6
1.6.2 纯金属的氧化 7
1.6.3 合金的氧化 7
1.7 实验目的与意义 8
2 实验方案 9