合金元素对DZ445合金高温氧化行为的影响

摘要DZ445合金是在K445合金成分的基础上调整化学成分，并采用定向凝固工艺，发展而成的定向凝固柱晶高温合金，定向凝固镍基高温合金DZ445是一种新型重型燃机涡轮叶片用材料，作为涡轮叶片用材料，DZ445合金应具有较好的抗疲劳性能。通过X射线衍射分析、扫描电镜和能谱分析等手段对定向凝固柱晶合金DZ445，在810℃和910℃的氧化行为进行了初步地研究。实验结果表明：定向凝固柱晶合金DZ445经过810℃和910℃氧化后，合金表层都生成了以Cr2O3为主的氧化膜同时还有尺寸较大的（Ti，Ta）O4颗粒物生成。氧化层分为两层，外层主要由Cr2O3和（Ti，Ta）O4组成，内层由NiCr2O4、TiO2和AlO3层组成，内层以AlO3为主。随氧化温度和氧化时间的增加颗粒物（Ti，Ta）O4表面产生尺寸较大的贯穿裂纹和孔洞，影响了合金表面氧化膜的完整连续性，对合金的抗氧化性能有不利影响。52675

毕业论文关键词：定向凝固；高温合金；合金元素；高温氧化行为

Abstract DZ445 alloy is adjusted on the basis of K445 alloy composition on the chemical composition, and the use of directional solidification process, directionally solidified columnar grain superalloy evolved, directionally solidified nickel-base superalloy DZ445 is a new heavy-duty gas turbine turbine blade materials, as turbine blade materials, DZ445 alloy should have good fatigue resistance.Through X-ray diffraction analysis, scanning electron microscope and energy spectrum analysis of short hand of directionally solidified columnar crystal alloy dz445 in the oxidation behavior of 81 and 91 degrees Celsius for a preliminary study. The experimental results show that the surface layer of the alloy is formed on the surface of the （Ti，Ta）O4 particles with Cr2O3 as the main oxide film and the size of the particles formed by the DZ445 based alloy coating. The oxide layer is pided into two layers, the outer layer is mainly composed of Cr2O3 and （Ti，Ta）O4, the inner layer is composed of NiCr2O4, TiO2 and AlO3 layer, and the inner layer is mainly composed of AlO3 and. With increasing oxidation temperature and oxidation time increasing particulate matter （Ti，Ta）O4 surface larger size through cracks and holes, the effect of the oxide film on the surface of the alloy of complete continuity and antioxidant properties of the alloy have adverse effects.

KeyWords： directionally solidified；superalloy；alloying element；Oxidation behavior at high temperature

1. 绪论 1

1.1 高温合金的简述与发展 1

1.2 高温合金 1

1.2.1 定向凝固高温合金 1

1.2.2 单晶高温合金 2

1.3 不同基体的高温合金 2

1.3.1 铁基高温合金 2

1.3.2 钴基高温合金 3

1.3.3 镍基高温合金 3

1.4 GH4169合金简介 3

1.5 K445高温合金简介 4

1.6 DZ445高温合金简述 4

1.7 DZ445合金性质 4

1.7.1 DZ445合金的热疲劳性能 4

1.7.2 DZ445合金的力学性能 5

1.8 合金的氧化 5

1.8.1 合金的内氧化 5

1.8.2 合金的外氧化 6

1.8.3 合金的选择氧化 6 合金元素对DZ445合金高温氧化行为的影响:http://www.751com.cn/cailiao/lunwen_56653.html