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Full-Text Articles in Engineering

Advances In Additively Manufactured Titanium Alloys By Powder Bed Fusion And Directed Energy Deposition: Microstructure, Defects, And Mechanical Behavior, Hongyi Y. Ma, J. C. Wang, Peng Qin, Y. J. Liu, L. Y. Chen, L. Q. Wang, Laichang Zhang Jun 2024

Advances In Additively Manufactured Titanium Alloys By Powder Bed Fusion And Directed Energy Deposition: Microstructure, Defects, And Mechanical Behavior, Hongyi Y. Ma, J. C. Wang, Peng Qin, Y. J. Liu, L. Y. Chen, L. Q. Wang, Laichang Zhang

Research outputs 2022 to 2026

Ti and its alloys have been broadly adopted across various industries owing to their outstanding properties, such as high strength-to-weight ratio, excellent fatigue performance, exceptional corrosion resistance and so on. Additive manufacturing (AM) is a complement to, rather than a replacement for, traditional manufacturing processes. It enhances flexibility in fabricating complex components and resolves machining challenges, resulting in reduced lead times for custom designs. However, owing to distinctions among various AM technologies, Ti alloys fabricated by different AM methods usually present differences in microstructure and defects, which can significantly influence the mechanical performance of built parts. Therefore, having an in-depth …


Recent Innovations In Laser Additive Manufacturing Of Titanium Alloys, Jinlong Su, Fulin Jiang, Jie Teng, Lequn Chen, Ming Yan, Guillermo Requena, Lai-Chang Zhang, Y. Morris Wang, Ilya V. Okulov, Hongmei Zhu, Chaolin Tan Jun 2024

Recent Innovations In Laser Additive Manufacturing Of Titanium Alloys, Jinlong Su, Fulin Jiang, Jie Teng, Lequn Chen, Ming Yan, Guillermo Requena, Lai-Chang Zhang, Y. Morris Wang, Ilya V. Okulov, Hongmei Zhu, Chaolin Tan

Research outputs 2022 to 2026

Titanium (Ti) alloys are widely used in high-tech fields like aerospace and biomedical engineering. Laser additive manufacturing (LAM), as an innovative technology, is the key driver for the development of Ti alloys. Despite the significant advancements in LAM of Ti alloys, there remain challenges that need further research and development efforts. To recap the potential of LAM high-performance Ti alloy, this article systematically reviews LAM Ti alloys with up-to-date information on process, materials, and properties. Several feasible solutions to advance LAM Ti alloys are reviewed, including intelligent process parameters optimization, LAM process innovation with auxiliary fields and novel Ti alloys …


Revised Semiempirical Approach To Predict The Occurrence Of Twinning In Titanium Alloys, Chirag Dhirajlal Rabadia, Syed Faraz Jawed, Jincheng Wang, Milind Siddhpura, Arti Siddhpura Dec 2021

Revised Semiempirical Approach To Predict The Occurrence Of Twinning In Titanium Alloys, Chirag Dhirajlal Rabadia, Syed Faraz Jawed, Jincheng Wang, Milind Siddhpura, Arti Siddhpura

Research outputs 2014 to 2021

A revised semiempirical approach, considering the average values of the valence electron to atom ratio (e/a̅) and a difference in atomic radii of alloying element/s and the base element (Δr¯), is proposed to predict the twin formation in titanium alloys. The revised e/ā versus Δr¯ diagram is plotted, considering the reported results of 90 titanium alloys fabricated using various processing methods. A new twin/slip boundary has been plotted and recommended based on the revised e/ā versus Δr¯ diagram. The conventional maximum limit reported for the twinning in titanium alloys is e/ā = 4.20; however, it has been found that twinning …


Review On Machining Of Additively Manufactured Nickel And Titanium Alloys, Navneet Khanna, Kishan Zadafiya, Tej Patel, Yusuf Kaynak, Rizwan Abdul, Rahman Rashid, Ana Vafadar Jan 2021

Review On Machining Of Additively Manufactured Nickel And Titanium Alloys, Navneet Khanna, Kishan Zadafiya, Tej Patel, Yusuf Kaynak, Rizwan Abdul, Rahman Rashid, Ana Vafadar

Research outputs 2014 to 2021

The machining of nickel and titanium-based superalloy components is very expensive and involves unusually high lead times compared with other engineering metals such as steels and aluminum. This has led to the development of most suitable additive manufacturing (AM) processes to fabricate these difficult-to-machine metals into near-net shape parts, thereby reducing the lead time and material waste, and significantly increasing productivity. Nonetheless, finish machining is still required on the AMed metal components to meet the dimensional and surface requirements of the application. Several research studies have investigated the machinability of AMed nickel and titanium alloy workpieces and have compared the …


Corrosion Behavior And Characteristics Of Passive Films Of Laser Powder Bed Fusion Produced Ti-6al-4v In Dynamic Hank’S Solution, Liang-Yu Chen, Hong-Yue Zhang, Chuanbo Zheng, Hong-Yu Yang, Peng Qin, Cuihua Zhao, Sheng Lu, Shun-Xing Liang, Linjiang Chai, Lai-Chang Zhang Jan 2021

Corrosion Behavior And Characteristics Of Passive Films Of Laser Powder Bed Fusion Produced Ti-6al-4v In Dynamic Hank’S Solution, Liang-Yu Chen, Hong-Yue Zhang, Chuanbo Zheng, Hong-Yu Yang, Peng Qin, Cuihua Zhao, Sheng Lu, Shun-Xing Liang, Linjiang Chai, Lai-Chang Zhang

Research outputs 2014 to 2021

The corrosion behavior of laser powder bed fusion produced (L-PBF-produced) titanium alloys involving flowing body fluid is still unclear. Therefore, this work investigates in vitro corrosion behavior and the characteristics of passive films formed on L-PBF-produced Ti–6Al–4V in both static and dynamic Hank’s solutions. Electrochemical measurements, immersion tests, X-ray photoelectron spectroscopy and scanning electron microscopy were conducted. In comparison to the L-PBF-produced Ti–6Al–4V in static Hank’s solution, the samples showed lower charge transfer resistance and higher passivation current density (anodic current density as well) in dynamic Hank’s solution. Meanwhile, a more apparent deposition of apatite and hydroxyapatite is found on …


Deformation And Toughness Behavior Of Β -Type Titanium Alloys Comprising C15-Type Laves Phase, C. D. Rabadia, Y. J. Liu, S. F. Jawed, L. Q. Wang, H. Sun, L. C. Zhang Sep 2020

Deformation And Toughness Behavior Of Β -Type Titanium Alloys Comprising C15-Type Laves Phase, C. D. Rabadia, Y. J. Liu, S. F. Jawed, L. Q. Wang, H. Sun, L. C. Zhang

Research outputs 2014 to 2021

Laves phases are effective in tailoring the mechanical properties of alloys used for structural engineering applications. Therefore, it is an emerging research significance to investigate the deformation features of alloys comprising a Laves phase. In this work, the Ti–33Zr–xFe–yCr (x = 5, 7 wt% and y = 2, 4 wt%) alloys were designed in such a way that a Laves phase would form in the investigated Ti–33Zr–xFe–yCr alloys and later, cast by cold crucible levitation melting. All the as-cast alloys exhibit a face-centered cubic C15-type Laves phase along with a dominant β phase. The volume fraction of C15 Laves phase …


Microstructure And Mechanical Behavior Of Metastable Beta Type Titanium Alloys, Chirag Dhirajlal Rabadia Jan 2020

Microstructure And Mechanical Behavior Of Metastable Beta Type Titanium Alloys, Chirag Dhirajlal Rabadia

Theses: Doctorates and Masters

Current biomaterials such as stainless steel, Co-Cr alloys, commercially pure titanium and Ti-6Al- 4V either possess poor mechanical compatibility and/or produce toxic effects in the human body after several years of usage. Consequently, there is an enormous demand for long-lasting biomaterials which provide a better combination of mechanical, corrosion and biological properties. In addition to this, alloys used in high-strength applications possess either high-strength or large plasticity. However, a high-strength alloy should possess a better blend of both strength and plasticity when used in high-strength applications. Metastable β-titanium alloys are the best suited alloys for biomedical and high-strength applications because …


Evaluation Of Microstructure Variation Of Tc11 Alloy After Electroshocking Treatment, Lechun Xie, Chang Liu, Yanli Song, Haojie Guo, Zhongqi Wang, Lin Hua, Liqiang Wang, Lai-Chang Zhang Jan 2020

Evaluation Of Microstructure Variation Of Tc11 Alloy After Electroshocking Treatment, Lechun Xie, Chang Liu, Yanli Song, Haojie Guo, Zhongqi Wang, Lin Hua, Liqiang Wang, Lai-Chang Zhang

Research outputs 2014 to 2021

Electro-shocking treatment (EST) has been investigated as a pathway to optimise the microstructure and mechanical properties of titanium alloys. The thermal conditions introduced by EST resulted in a phase transformation from α to β. The fraction of β phase decreased from 25.27% to 19.47% after EST for 0.02 s, which was possibly caused by the recrystallization of α phase. The application of EST for 0.04 s resulted in an increase in volume fraction of the β phase to 26.95%. The energy introduced by EST resulted in changes to the direction and intensity of texture within the microstructure with the texture …


Deformation And Strength Characteristics Of Laves Phases In Titanium Alloys, Chirag D. Rabadia, Y. J. Liu, Liang-Yu Chen, Syed F. Jawed, L. Q. Wang, Hongqi Sun, Laichang Zhang Jan 2019

Deformation And Strength Characteristics Of Laves Phases In Titanium Alloys, Chirag D. Rabadia, Y. J. Liu, Liang-Yu Chen, Syed F. Jawed, L. Q. Wang, Hongqi Sun, Laichang Zhang

Research outputs 2014 to 2021

The superior reinforcement nature of Laves phases make them suitable for high-strength applications. Therefore, investigations on the deformation and strength characteristics of Laves phases are useful in development of an improved Laves phase-reinforced alloy. In this work, the Vickers micro-indentation method is used to evaluate and compare the deformation and strength characteristics of a hexagonal close-packed Laves phase (C14-type) in Ti-35Zr-5Fe-6Mn (wt%) and a face-centered cubic Laves phase (C15-type) in Ti-33Zr-7Fe-4Cr (wt%), considering the same volume fraction of Laves phase (~7.0%) in these alloys. Moreover, the effects of higher volume fraction of Laves phase (19.4%) on indentation-based deformation features are …


Nanoindentation Characterization On Local Plastic Response Of Ti-6al-4v Under High-Load Spherical Indentation, Yan Wen, Lechun Xie, Zhou Wang, Liqiang Wang, Weijie Lu, Laichang Zhang Jan 2019

Nanoindentation Characterization On Local Plastic Response Of Ti-6al-4v Under High-Load Spherical Indentation, Yan Wen, Lechun Xie, Zhou Wang, Liqiang Wang, Weijie Lu, Laichang Zhang

Research outputs 2014 to 2021

After high-load spherical indentation treatment, the variations of hardness on the plastic zone of Ti-6Al-4V were investigated via nanoindentation method. The hardness within the center of plastic zone was measured by nanoindenter, and the magnitude decreased gradually along the depth, which were caused by the different extent of plastic deformation under the residual imprint. The microstructure of indentation were observed using scanning electron microscope (SEM) before and after surface etching, and the results showed that the microhardness revealed the average hardness of α and β phases of Ti-6Al-4V. The maximum hardness reached 6.438 GPa in the depth of 132 μm. …


Beta-Type Ti-Nb-Zr-Cr Alloys With Large Plasticity And Significant Strain Hardening, Syed F. Jawed, Chirag D. Rabadia, Y. J. Liu, L. Q. Wang, Y. H. Li, X. H. Zang, Laichang C. Zhang Jan 2019

Beta-Type Ti-Nb-Zr-Cr Alloys With Large Plasticity And Significant Strain Hardening, Syed F. Jawed, Chirag D. Rabadia, Y. J. Liu, L. Q. Wang, Y. H. Li, X. H. Zang, Laichang C. Zhang

Research outputs 2014 to 2021

A series of Ti-25Nb-8Zr-xCr (x = 0, 2, 4, 6, 8 wt%) alloys were designed based on DV-Xα cluster method and e=a-Δr diagram with an anticipation to obtain high plasticity and significant strain hardening. The designed alloys were produced through cold crucible levitation melting technique in order to effectively investigate their micro-structures and mechanical properties. The addition of Cr significantly enhances the β stability in the microstructures of the Ti-25Nb-8Zr-xCr alloys. Both yield strength and hardness of the studied alloys increase due to the effect of solid-solution strengthening. By contrast, the plasticity, maximum strength and strain hardening rate are influenced …


Processing, Microstructure And Mechanical Properties Of Beta-Type Titanium Porous Structures Made By Additive Manufacturing, Yujing Liu Jan 2017

Processing, Microstructure And Mechanical Properties Of Beta-Type Titanium Porous Structures Made By Additive Manufacturing, Yujing Liu

Theses: Doctorates and Masters

Tissue engineering through the application of a low modulus, high strength format as a potential approach for increasing the durability of bone implants has been attracting significant attention. Titanium alloys are widely used for biomedical applications because of their low modulus, high biocompatibility, specific strength and corrosion resistance. These reasons affirm why titanium alloy is selected as the specific material to research. The development of low modulus biomaterials is considered to be an effective method to remove the mismatch between biomaterial implants and surrounding bone tissue, thereby reducing the risk of bone resorption. So far, Ti–24Nb–4Zr–8Sn alloy (abbreviated hereafter as …


Equiaxed Ti-Based Composites With High Strength And Large Plasticity Prepared By Sintering And Crystallizing Amorphous Powder, Lehua Liu, Chao Yang, L. M. Kang, Yan Long, Zhiyu Xiao, Peijie Li, Laichang Zhang Jan 2016

Equiaxed Ti-Based Composites With High Strength And Large Plasticity Prepared By Sintering And Crystallizing Amorphous Powder, Lehua Liu, Chao Yang, L. M. Kang, Yan Long, Zhiyu Xiao, Peijie Li, Laichang Zhang

Research outputs 2014 to 2021

High-performance titanium alloys with an equiaxed composite microstructure were achieved by sintering and crystallizing amorphous powder. By introducing a second phase in a β-Ti matrix, series of optimized Ti-Nb-Fe-Co-Al and Ti-Nb-Cu-Ni-Al composites, which have a microstructure composed of ultrafine-grained and equiaxed CoTi2 or (Cu,Ni)Ti2 precipitated phases surrounded by a ductile β-Ti matrix, were fabricated by sintering and crystallizing mechanically alloyed amorphous powder. The as-fabricated composites exhibit ultra-high ultimate compressive strength of 2585MPa and extremely large compressive plastic strain of around 40%, which are greater than the corresponding ones for most titanium alloys. In contrast, the alloy fabricated by …