选择性激光熔化技术制备γ-TiAl基合金的组织与性能
发布时间：2021-10-28 06:59
γ-TiAl基合金由于密度低,具有较高的强度和抗蠕变性能而成为重要的高温材料,然其较低的延展性和抗氧化能力限制了其应用和发展。选区激光熔化（Selective laser melting,SLM）技术是一种常用的增材制造技术,该技术不需要特殊的加工工具和铸模,在3D模型的基础上通过逐层堆积来实现小批量和复杂结构零件的加工,特别适用于难变形材料的加工。近年来,人们研究了激光选区熔化制备γ-TiAl基合金的组织和性能,发现由于较快的冷却速度,合金具有更细小的内部组织,同时合金强度也得以提高。B,V,Y,Mo,和Cr等合金化元素的添加也在一定程度提高了合金的延展性和抗氧化性但和理想效果仍有差距。因此,为了进一步提高γ-TiAl基合金的延展性和高温抗氧化性,本研究将Nb元素添加入该合金并采用电磁搅拌辅助激光选区熔化技术来加工不容成分的合金。本研究中,通过激光选区熔化技术（SLM）在TC4合金基板上加工了不同Nb含量的Ti-Al-Mn-Nb合金,分析了不同Nb添加量合金的组织和性能。结果显示:合金组织主要由四方点阵结构的γ-TiAl相和密排六方点阵结构的α2-Ti...
【文章来源】：大连理工大学辽宁省 211工程院校 985工程院校 教育部直属院校
【文章页数】：74 页
【学位级别】：硕士
【文章目录】：
摘要
Abstract
1. Introduction
1.1 Applications of γ-Ti Al based alloys
1.1.1 Aerospace applications
1.1.2 Automotive sectors
1.2 Intermetallics
1.3 Ti and its properties
1.4 Al and it's properties
1.5 Nb and its properties
1.6 Titanium aluminde
1.6.1 Intermetallic compounds
1.6.2 Microstructure of γ-Ti Al
1.7 Processing methods of γ-Ti Al
1.7.1 Additive manufacturing
1.7.2 Selective laser Melting
1.8 Residual stresses
1.9 Effect of electromagnetic stirring
1.9.1 Rotating electromagnetic stirring
1.9.2 Linear electromagnetic stirring
1.9.3 Pulsed magnetic field
2. Experimental materials and methods
2.1 Materials
2.2 Selective laser melting (SLM)
2.3 Material characterizations
2.3.1 X-ray diffraction (XRD)
2.3.2 Scanning electron microscope (SEM)
2.4 Mechanical test procedures
2.4.1 Microhardness
2.4.2 Compression test
2.5 Tribological test procedures
2.6 High temperature oxidation-resistance
2.7 Rotating electromagnetic stirring
3. Results and discussions
3.1 The effect of Nb on microstructure of γ-Ti Al
3.1.1 Phase identification
3.1.2 Phase morphologies
3.2 The effect of Nb on mechanical properties of γ-Ti Al
3.2.1 Microhardness
3.2.2 Compressive analysis
3.3 The effect of Nb on tribological properties of γ-Ti Al
3.4 The effect of Nb on high temperature oxidation resistance of γ-Ti Al
4. Crack and holes analysis
4.1 Crack formation
4.2 Holes formation
5. Results and discussions
5.1 The effect of EMS on microstructure and microhardness of γ-Ti Al
5.1.1 Phase identification
5.1.2 Phase morphologies
5.1.3 Microhardness
Conclusions
References
Appendix A
Research Projects and Publications in Master Study
Acknowledgement
本文编号：3462445
【文章来源】：大连理工大学辽宁省 211工程院校 985工程院校 教育部直属院校
【文章页数】：74 页
【学位级别】：硕士
【文章目录】：
摘要
Abstract
1. Introduction
1.1 Applications of γ-Ti Al based alloys
1.1.1 Aerospace applications
1.1.2 Automotive sectors
1.2 Intermetallics
1.3 Ti and its properties
1.4 Al and it's properties
1.5 Nb and its properties
1.6 Titanium aluminde
1.6.1 Intermetallic compounds
1.6.2 Microstructure of γ-Ti Al
1.7 Processing methods of γ-Ti Al
1.7.1 Additive manufacturing
1.7.2 Selective laser Melting
1.8 Residual stresses
1.9 Effect of electromagnetic stirring
1.9.1 Rotating electromagnetic stirring
1.9.2 Linear electromagnetic stirring
1.9.3 Pulsed magnetic field
2. Experimental materials and methods
2.1 Materials
2.2 Selective laser melting (SLM)
2.3 Material characterizations
2.3.1 X-ray diffraction (XRD)
2.3.2 Scanning electron microscope (SEM)
2.4 Mechanical test procedures
2.4.1 Microhardness
2.4.2 Compression test
2.5 Tribological test procedures
2.6 High temperature oxidation-resistance
2.7 Rotating electromagnetic stirring
3. Results and discussions
3.1 The effect of Nb on microstructure of γ-Ti Al
3.1.1 Phase identification
3.1.2 Phase morphologies
3.2 The effect of Nb on mechanical properties of γ-Ti Al
3.2.1 Microhardness
3.2.2 Compressive analysis
3.3 The effect of Nb on tribological properties of γ-Ti Al
3.4 The effect of Nb on high temperature oxidation resistance of γ-Ti Al
4. Crack and holes analysis
4.1 Crack formation
4.2 Holes formation
5. Results and discussions
5.1 The effect of EMS on microstructure and microhardness of γ-Ti Al
5.1.1 Phase identification
5.1.2 Phase morphologies
5.1.3 Microhardness
Conclusions
References
Appendix A
Research Projects and Publications in Master Study
Acknowledgement
本文编号：3462445
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