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Advanced Characterization of Deformation Mechanisms in Additively Manufactured Metallic Systems
Advanced Characterization of Deformation Mechanisms in Additively Manufactured Metallic Systems
상세정보
- 자료유형
- 학위논문 서양
- 최종처리일시
- 20260202105642
- ISBN
- 9798270220006
- DDC
- 620.11
- 서명/저자
- Advanced Characterization of Deformation Mechanisms in Additively Manufactured Metallic Systems
- 발행사항
- [Sl] : University of California, Los Angeles, 2025
- 발행사항
- Ann Arbor : ProQuest Dissertations & Theses, 2025
- 형태사항
- 189 p
- 주기사항
- Source: Dissertations Abstracts International, Volume: 87-06, Section: B.
- 주기사항
- Advisor: Wang, Yinmin.
- 학위논문주기
- Thesis (Ph.D.)--University of California, Los Angeles, 2025.
- 초록/해제
- 요약Advances in metal additive manufacturing (AM) are reshaping the design of structural alloys with exceptional performance. This dissertation investigates the deformation behavior of laser powder-bed-fusion (L-PBF) metals through in-situ synchrotron X-ray diffraction (SXRD) and electron microscopy, establishing a mechanistic framework that connects AM-induced microstructures to strength and ductility.The first part of this work addresses the printability barrier in refractory metals. To our current knowledge, we demonstrate the first near-fully dense, crack-free L-PBF tungsten-based alloy by introducing a small boron addition (0.3 wt.%). This modification disrupts solidification-cracking pathways and enables unprecedented tensile ductility at 800 °C in a material historically viewed as unprintable and intrinsically brittle. These findings establish a new foundation for refractory AM alloys in fusion and extreme-environment applications.The second part focuses on a TiC-inoculated Al-Mg-Zn-Cu alloy designed for high performance. TiC nanoparticles provide solidification control, producing an equiaxed fine-grained structure that remains stable through post-processing. Hot isostatic pressing (HIP) and T6 aging create a hierarchical precipitation architecture consisting of a grain-boundary MgZn₂ cage and dense intragranular η'/cluster networks. In-situ SXRD measurements of lattice-strain deviation, peak broadening, and diffraction-intensity changes reveal how plasticity initiates and load progressively transfers between the matrix and its precipitates. These mechanisms yield a rare strength-ductility synergy, resulting in the highest specific ultimate tensile strength (SUTS) reported for any aluminum alloy (269MPa/g/cm3)-exceeding even conventional Ti-6Al-4V.Complementary SXRD studies of pure Cu, equiatomic CoCrNi, and 316L stainless steel provide a reference framework for interpreting defect evolution in face-centered cubic (FCC) AM metals. Cu enables unambiguous quantification of dislocation-controlled hardening, whereas CoCrNi and 316L illustrate the influence of stacking-fault energy (SFE) on lattice-strain deviation and reflection-dependent behavior. Together with Al, these comparisons show that SXRD response cannot be universally interpreted without accounting for intrinsic elastic properties, SFE, slip-system accessibility, and defect character.Overall, this dissertation demonstrates that in-situ SXRD is uniquely capable of revealing microstructural load sharing and defect evolution under realistic operating conditions. Coupled with AM-specific microstructure design strategies-from nanoparticle-stabilized grain refinement in Al to boron-driven solidification control in W-B-these results define a pathway for engineering the next generation of lightweight and extreme-environment structural materials.
- 일반주제명
- Materials science
- 일반주제명
- Chemistry
- 일반주제명
- Applied physics
- 일반주제명
- Engineering
- 키워드
- Metals
- 기타저자
- University of California, Los Angeles Materials Science and Engineering 0328
- 기본자료저록
- Dissertations Abstracts International. 87-06B.
- 전자적 위치 및 접속
- 로그인 후 원문을 볼 수 있습니다.
MARC
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■006m o d
■007cr#unu||||||||
■020 ▼a9798270220006
■035 ▼a(MiAaPQ)AAI32398797
■040 ▼aMiAaPQ▼cMiAaPQ
■0820 ▼a620.11
■1001 ▼aTalignani, Alberico.
■24510▼aAdvanced Characterization of Deformation Mechanisms in Additively Manufactured Metallic Systems
■260 ▼a[Sl]▼bUniversity of California, Los Angeles▼c2025
■260 1▼aAnn Arbor▼bProQuest Dissertations & Theses▼c2025
■300 ▼a189 p
■500 ▼aSource: Dissertations Abstracts International, Volume: 87-06, Section: B.
■500 ▼aAdvisor: Wang, Yinmin.
■5021 ▼aThesis (Ph.D.)--University of California, Los Angeles, 2025.
■520 ▼aAdvances in metal additive manufacturing (AM) are reshaping the design of structural alloys with exceptional performance. This dissertation investigates the deformation behavior of laser powder-bed-fusion (L-PBF) metals through in-situ synchrotron X-ray diffraction (SXRD) and electron microscopy, establishing a mechanistic framework that connects AM-induced microstructures to strength and ductility.The first part of this work addresses the printability barrier in refractory metals. To our current knowledge, we demonstrate the first near-fully dense, crack-free L-PBF tungsten-based alloy by introducing a small boron addition (0.3 wt.%). This modification disrupts solidification-cracking pathways and enables unprecedented tensile ductility at 800 °C in a material historically viewed as unprintable and intrinsically brittle. These findings establish a new foundation for refractory AM alloys in fusion and extreme-environment applications.The second part focuses on a TiC-inoculated Al-Mg-Zn-Cu alloy designed for high performance. TiC nanoparticles provide solidification control, producing an equiaxed fine-grained structure that remains stable through post-processing. Hot isostatic pressing (HIP) and T6 aging create a hierarchical precipitation architecture consisting of a grain-boundary MgZn₂ cage and dense intragranular η'/cluster networks. In-situ SXRD measurements of lattice-strain deviation, peak broadening, and diffraction-intensity changes reveal how plasticity initiates and load progressively transfers between the matrix and its precipitates. These mechanisms yield a rare strength-ductility synergy, resulting in the highest specific ultimate tensile strength (SUTS) reported for any aluminum alloy (269MPa/g/cm3)-exceeding even conventional Ti-6Al-4V.Complementary SXRD studies of pure Cu, equiatomic CoCrNi, and 316L stainless steel provide a reference framework for interpreting defect evolution in face-centered cubic (FCC) AM metals. Cu enables unambiguous quantification of dislocation-controlled hardening, whereas CoCrNi and 316L illustrate the influence of stacking-fault energy (SFE) on lattice-strain deviation and reflection-dependent behavior. Together with Al, these comparisons show that SXRD response cannot be universally interpreted without accounting for intrinsic elastic properties, SFE, slip-system accessibility, and defect character.Overall, this dissertation demonstrates that in-situ SXRD is uniquely capable of revealing microstructural load sharing and defect evolution under realistic operating conditions. Coupled with AM-specific microstructure design strategies-from nanoparticle-stabilized grain refinement in Al to boron-driven solidification control in W-B-these results define a pathway for engineering the next generation of lightweight and extreme-environment structural materials.
■590 ▼aSchool code: 0031.
■650 4▼aMaterials science
■650 4▼aChemistry
■650 4▼aApplied physics
■650 4▼aEngineering
■653 ▼aAdditive manufacturing
■653 ▼aElectron microscopy
■653 ▼aMetals
■653 ▼aSynchrotron radiation
■653 ▼aSynchrotron X-ray diffraction
■690 ▼a0794
■690 ▼a0537
■690 ▼a0215
■690 ▼a0485
■71020▼aUniversity of California, Los Angeles▼bMaterials Science and Engineering 0328.
■7730 ▼tDissertations Abstracts International▼g87-06B.
■790 ▼a0031
■791 ▼aPh.D.
■792 ▼a2025
■793 ▼aEnglish
■85640▼uhttp://www.riss.kr/pdu/ddodLink.do?id=T17360944▼nKERIS▼z이 자료의 원문은 한국교육학술정보원에서 제공합니다.
