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摘要：NiAl具有很多优异的性能，人们对它进行研究的最大兴趣集中在用它制作先进航空发动机的高温结构部件。与Ni基高温合金相比，NiAl具有许多突出的优点，如拥有较高的熔点，较低的密度，良好的热传导性，优异的抗氧化性能等，作为高温合金潜在的替代材料，在新材料的研制中受到了特别的重视，而为了进一步提高NiAl的高温力学性能加入了Cr，Mo，Hf，Ho等合金元素，使其组织和性能发生了改变。合金元素对多元合金高温氧化性能有非常重要的影响，其综合作用机制比较复杂。本课题的主要是研究NiAl基共晶合金在800℃、900℃高温度空气中的氧化行为及氧化机理，结果表明：NiAl-Cr(Mo)-Hf-Ho合金高温氧化后表面得到Al2O3、Cr2O3、HfO2复合氧化膜，稀土元素Hf、Ho的加入提高了外氧化膜附着性，提高了合金的抗氧化性。27803
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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