Article
Chemistry, Physical
J. R. Kennedy, A. E. Davis, A. E. Caballero, N. Byres, S. Williams, E. J. Pickering, P. B. Prangnell
Summary: Adding low levels of yttrium (Y) can reduce the width of solidified columnar beta grains in large titanium parts and induce a columnar-to-equiaxed transition (CET) in the latter stages of melt pool solidification, leading to reduced texture and increased solidification velocity.
JOURNAL OF ALLOYS AND COMPOUNDS
(2022)
Article
Nanoscience & Nanotechnology
Aitang Xue, Xin Lin, Lilin Wang, Xufei Lu, Hanlin Ding, Weidong Huang
Summary: The coarsening of equiaxed beta-grains in titanium alloy produced by additive manufacturing under high-temperature thermal cycling was reported. A modified model was proposed to predict the coarsened beta-grain size, providing guidance for the composition design of titanium alloy with fine equiaxed beta-grains.
SCRIPTA MATERIALIA
(2021)
Article
Engineering, Manufacturing
J. R. Kennedy, A. E. Davis, A. E. Caballero, S. Williams, E. J. Pickering, P. B. Prangnell
Summary: The study explores the use of TiN and ZrN as grain refining inoculants to reduce the size of beta grains and improve their morphology in Wire-Arc Additive Manufacturing (WAAM) of titanium components.
ADDITIVE MANUFACTURING
(2021)
Review
Engineering, Manufacturing
A. Sola, A. Trinchi
Summary: The role of boron (B) in microstructural changes in titanium (Ti) castings has been clarified, but its effects in additive manufacturing (AM) are still debated. Many studies have found that B can refine the microstructure in Ti-based AM parts and increase their strength. However, there are still issues such as deviation from equilibrium due to fast cooling in AM, which can lead to the formation of out-of-equilibrium phases, and the growth of TiB may negatively impact the ductility and crack propagation resistance of AM parts, requiring appropriate remediation strategies.
VIRTUAL AND PHYSICAL PROTOTYPING
(2023)
Article
Engineering, Manufacturing
A. Sola, A. Trinchi
Summary: This review examines the impact of boron on the microstructure of titanium during additive manufacturing. It discusses the refining effect of boron on the microstructure and its role in regulating columnar grain growth. However, it also highlights the potential issues that can arise during fast cooling, such as eutectic point shift and formation of out-of-equilibrium phases, as well as the impact of TiB growth on ductility and crack propagation resistance in additive manufacturing parts.
VIRTUAL AND PHYSICAL PROTOTYPING
(2023)
Article
Nanoscience & Nanotechnology
Siyu Zhang, Qiang Zhang, Min Zheng, Yunlong Hu, Shang Sui, Jing Chen, Xin Lin
Summary: Increasing powder feed rate can effectively promote the columnar to equiaxed transition of Ti5Al2Sn2Zr4Mo4Cr titanium alloy during the LSF process, but excessively high powder feed rate does not further refine beta grains, especially near the fusion lines.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2021)
Article
Engineering, Manufacturing
C. H. Ng, M. J. Bermingham, M. S. Dargusch
Summary: High energy input additive manufacturing technologies, such as wire-based directed energy deposition, have high deposition rates but can result in coarse microstructures and defects. This work demonstrates a method to produce high-quality additively manufactured products using low-quality feedstock materials that are usually considered unsuitable. By intentionally introducing large pores using contaminated wire feedstock in a metastable β-Ti alloy, and subsequent hot isostatic pressing, porosity-free parts with refined grain size and excellent ductility can be obtained through dynamic recrystallisation. This approach is applicable to various metallic alloys produced by other additive manufacturing techniques, allowing the engineering of completely homogenous equiaxed grain microstructures.
ADDITIVE MANUFACTURING
(2023)
Article
Engineering, Manufacturing
C. H. Ng, M. J. Bermingham, M. S. Dargusch
Summary: This study investigates the improvement of columnar grain structure in titanium alloys by thermal post processing treatments. The results show that Hot Isostatic Pressing (HIPing) can promote the formation of equiaxed grains, significantly refine the grain size, and weaken the texture intensity. Evidence of grain recrystallization processes including discontinuous dynamic recrystallization (DDRX) and dynamic recovery (DRV) is also observed.
ADDITIVE MANUFACTURING
(2022)
Article
Engineering, Manufacturing
Danni Huang, Qiyang Tan, Yinghao Zhou, Yu Yin, Feng Wang, Tao Wu, Xianliang Yang, Zhiqi Fan, Yingang Liu, Jingqi Zhang, Han Huang, Ming Yan, Ming-Xing Zhang
Summary: LaB6 nanoparticles were identified as an effective inoculant for LAMed gamma-TiAl alloy, leading to significantly reduced grain size and transformed microstructural morphology. The inoculation treatment not only resulted in crack-free alloy fabrication but also increased compressive yield strength, ultimate strength, and strain to fracture, showing comparable or even better performance than conventionally processed gamma-TiAl alloys.
ADDITIVE MANUFACTURING
(2021)
Article
Engineering, Multidisciplinary
Cheng Kui, Zhang MingBo, Song Hao, Liu XinWang, Fan ZiTian, Wang GuiLan, Zhang HaiOu
Summary: This study explores the use of synchronous microrolling (HDMR) to address the problems of coarse columnar grains, inhomogeneous microstructure, and anisotropic mechanical properties in Ti-6Al-4V manufactured by wire and arc additive manufacturing (WAAM) and hybrid additive manufacturing with plasma-arc deposition. HDMR significantly refines the grains and improves isotropy, leading to better tensile properties in titanium alloys.
SCIENCE CHINA-TECHNOLOGICAL SCIENCES
(2022)
Article
Engineering, Multidisciplinary
Jinlong Su, Fulin Jiang, Chaolin Tan, Fei Weng, Fern Lan Ng, Min Hao Goh, Haiming Xie, Jin Liu, Youxiang Chew, Jie Teng
Summary: A novel multi-eutectoid elements alloying approach based on thermodynamic prediction is demonstrated to achieve refined microstructure and high strength in Ti alloys. Trace eutectoid alloy elements Co, Cr, and Ni were in-situ alloyed with the Ti-6Al-4V alloy through laser-directed energy deposition, resulting in superior combination of strength and ductility.
COMPOSITES PART B-ENGINEERING
(2023)
Article
Nanoscience & Nanotechnology
Xiaotong Pang, Zhihui Xiong, Shilong Liu, Junhao Sun, R. D. K. Misra, H. Kokawa, Zhuguo Li
Summary: Significant grain refinement of beta grains in metastable beta TB2 titanium alloy was achieved through the minor addition of zirconium diboride during laser melting deposition. The addition of 0.5 wt% ZrB2 resulted in smaller beta grains and improved mechanical properties, including higher ultimate tensile strength and ductility.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2022)
Article
Materials Science, Multidisciplinary
Qiang Wang, Kang Zhang, Dong Qiu, Wenjuan Niu
Summary: This study comprehensively investigated the effect of La2O3 addition on the microstructure and mechanical properties of CP-Ti fabricated through SLM, demonstrating that La2O3 can suppress massive phase transformation, refine grain size, and enhance mechanical properties through multiple strengthening mechanisms.
MATERIALS CHARACTERIZATION
(2021)
Article
Crystallography
Yucong Lei, Milad Ghayoor, Somayeh Pasebani, Ali Tabei
Summary: This study introduces a fast modeling approach for predicting texture evolution in metal additive manufacturing of stainless steel 304L, showing excellent consistency with validation experiments. The major novelty lies in the model's speed and extremely light computational load, with calibrations and predictions carried out in 9.2 s on a typical desktop computer.
Article
Chemistry, Physical
Yuhua Chen, Mingfang Xu, Timing Zhang, Jilin Xie, Kang Wei, Shanlin Wang, Limeng Yin, Peng He
Summary: Ultrasound-assisted wire and arc additive manufacturing (WAAM) can disrupt the growth of columnar grains, promote the transformation of grain orientation, improve material performance, and reduce anisotropy.
JOURNAL OF ALLOYS AND COMPOUNDS
(2022)
Article
Engineering, Industrial
Tao Zhang, Huigui Li, Hai Gong, Jialuo Ding, Yunxin Wu, Chenglei Diao, Xiaoyong Zhang, Stewart Williams
Summary: WAAM process is suitable for Inconel 718 components due to high deposition efficiency, but large columnar dendrites can lead to mechanical anisotropy. Cold rolling and warm rolling improve microstructure and tensile properties, with warm rolled material showing superior mechanical properties after HSA treatment. Grain refinement and strengthening precipitates contribute to the enhancements in mechanical properties. However, precipitation particles lead to lower elongation and trans-granular ductile fracture modes for both cold and warm rolled materials.
JOURNAL OF MATERIALS PROCESSING TECHNOLOGY
(2022)
Article
Materials Science, Multidisciplinary
Valeriy Gornyakov, Yongle Sun, Jialuo Ding, Stewart Williams
Summary: This study develops an efficient modeling approach to simulate wire arc additive manufacturing (WAAM) and rolling, providing steady-state solutions. By reducing the size of the model and applying proper constraints, the short models can achieve solutions equivalent to traditional full-size models. The study also analyzes the influential factors and implications of the strains and stresses generated by WAAM and rolling.
MODELLING AND SIMULATION IN MATERIALS SCIENCE AND ENGINEERING
(2022)
Article
Materials Science, Multidisciplinary
Bilal Ahmad, Xiang Zhang, Hua Guo, Michael E. Fitzpatrick, Leonor MacHado Santos Carvalho Neto, Stewart Williams
Summary: This paper investigates residual stress in WAAM Ti-6Al-4V walls built using different deposition strategies, namely single bead, parallel path, and oscillation path. The effects of interlayer hammer peening and interlayer temperature on residual stress are also examined. The findings show that the oscillation-path wall has the lowest residual stress values, while the single bead walls experience significant reduction in residual stress after removing the substrate.
Article
Materials Science, Multidisciplinary
Valeriy Gornyakov, Jialuo Ding, Yongle Sun, Stewart Williams
Summary: Post-build rolling can effectively mitigate residual stress and distortion in WAAM-built components, with slotted rollers being the most effective in introducing tensile plastic strain to counteract compressive strain generated during WAAM deposition. The rolling load and roller-to-wall friction coefficient significantly influence the effectiveness of the mitigation process, providing insights for the development of optimal post-build rolling processes in WAAM manufacturing.
MATERIALS & DESIGN
(2022)
Article
Nanoscience & Nanotechnology
Salome Sanchez, G. Gaspard, C. J. Hyde, I. A. Ashcroft, G. A. Ravi, A. T. Clare
Summary: Heat treatment is crucial for post additive manufactured products to optimize their metallurgical condition. This study focuses on LPBF alloy 718 and reveals the instability of its microstructure under thermal and thermomechanical exposure conditions. The study emphasizes the importance of appropriate heat treatment in relation to future service conditions, and provides recommendations for achieving an ideal microstructure for improved performance.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2022)
Article
Engineering, Manufacturing
Jan-Hendrik Groth, Mirco Magnini, Christopher Tuck, Adam Clare
Summary: Current biomimetic designs lack the incorporation of natural variance, while the presented methodology allows for the introduction of randomness through the superimposition of Gaussian distribution on regular arrays of parametric unit cells, preventing overlaps and providing a template for more accurate mimicry of biological structures across multi-physics problems.
ADDITIVE MANUFACTURING
(2022)
Article
Chemistry, Multidisciplinary
Alistair Speidel, Ivan Bisterov, Adam Thomas Clare
Summary: Counterfeit parts are a serious concern for manufacturers and end users, and preventing counterfeiting is of great importance. This article presents a rapid electrochemical jet engraving routine for encoding materials at lengths that can be imaged with a smartphone, in order to prevent counterfeiting. The encoded structures are stable and can withstand high temperatures, and individual identification can be achieved through rapid image recognition.
ADVANCED FUNCTIONAL MATERIALS
(2022)
Article
Engineering, Environmental
Deyu Yang, Rui Bao, Adam T. Clare, Kwing-So Choi, Xianghui Hou
Summary: This study proposes a new ice mitigation strategy called slippery liquid-impregnated porous metallic structure (LIPMS), which involves impregnating selected liquids into porous copper components to prevent ice formation. The results show that LIPMS can significantly delay the icing of water droplets, provide good frost resistance, and demonstrate ultra-low ice adhesion strength.
CHEMICAL ENGINEERING JOURNAL
(2022)
Article
Engineering, Manufacturing
Xin Chen, Chong Wang, Jialuo Ding, Phillippe Bridgeman, Stewart Williams
Summary: A three-dimensional wire-feeding model was developed to study the transient coupling behavior in wire plasma arc additive manufacturing. The model included a novel surface heat source model and an improved momentum source of the arc force. Simulation results agreed reasonably with experimental data, showing three different metal transfer modes as wire-feeding speed increased. The effects of arc shading and metal transfer on melt pool dynamics and bead shape were discussed.
JOURNAL OF MANUFACTURING PROCESSES
(2022)
Article
Engineering, Manufacturing
Yao Lu, Jun Wang, Stewart Williams, Lisong Zhu, Jialuo Ding, Chenglei Diao, Zhengyi Jiang
Summary: A functionally graded AlxCoCrFeNi high entropy alloy with a variation in Al concentration along the building direction was successfully produced using a hybrid powder-bed wire-based direct energy deposition process. The alloy exhibited a continuous transition from a single FCC structure to a major BCC+minor FCC dual-phase structure, which was facilitated by the remelting and reheating process during the deposition. The mechanical properties of the alloy showed higher strength and hardening rate but lower plasticity in areas with higher Al content.
ADDITIVE MANUFACTURING
(2023)
Article
Engineering, Civil
E. Ghafoori, H. Dahaghin, C. Diao, N. Pichler, L. Li, M. Mohri, J. Ding, S. Ganguly, S. Williams
Summary: In this study, the fatigue strengthening of damaged steel members was conducted using a directed energy deposition (DED) process called wire arc additive manufacturing (WAAM). Experimental and finite element (FE) simulation results showed that the WAAM process introduced compressive residual stresses at the crack tip and stress concentration at the root of the as-deposited WAAM, which can be mitigated by machining. Fractography analysis revealed that cracks were initiated at the WAAM-steel interface and microscopic observations showed that the microcracks were arrested by the porosities in the melted interface. Overall, this pioneering study highlights the promising potential of WAAM repair for combating fatigue damage in steel structures.
ENGINEERING STRUCTURES
(2023)
Article
Chemistry, Analytical
Charalampos Loukas, Momchil Vasilev, Rastislav Zimmerman, Randika K. W. Vithanage, Ehsan Mohseni, Charles N. MacLeod, David Lines, Stephen Gareth Pierce, Stewart Williams, Jialuo Ding, Kenneth Burnham, Jim Sibson, Tom O'Hare, Michael R. Grosser
Summary: The increasing demand for cost-efficient manufacturing and metrology inspection solutions in high-value manufacturing sectors has led to the integration of automated robotic solutions. However, the current manipulators using traditional programming approaches are inflexible and challenging to adapt to unique specifications per component. This study proposes a novel software system that utilizes an off-the-shelf force-torque sensor to achieve real-time kinesthetic guidance for path planning, resulting in improved performance and programming time.
Article
Chemistry, Multidisciplinary
Wenqi Li, Paul Dryburgh, Don Pieris, Rikesh Patel, Matt Clark, Richard J. Smith
Summary: This paper presents a method for measuring the microstructure of industrially relevant surface finishes. Spatially resolved acoustic spectroscopy is used to measure the microstructure, and the influence of surface roughness on the measurements is discussed. It is demonstrated that a wide range of surface finishes can be measured, but the correlation length of the roughness has a significant impact on the ability to detect surface waves.
APPLIED SCIENCES-BASEL
(2023)
Article
Chemistry, Analytical
Jian Qin, Javier Vives, Parthiban Raja, Shakirudeen Lasisi, Chong Wang, Thomas Charrett, Jialuo Ding, Stewart Williams, Jonathan Mark Hallam, Ralph Tatam
Summary: Part quality monitoring and control in wire-based directed energy deposition additive manufacturing (w-DEDAM) processes has been a topic of continuous interest. This paper investigates the behavior of interlayer deposition height in different wall regions, particularly the transition areas, when process parameters change. It also explores the potential of using geometry monitoring information for interlayer wall height compensation during w-DEDAM part-building.
Article
Engineering, Industrial
Guangyu Chen, Jialuo Ding, Yongle Sun, Xin Chen, Chong Wang, Goncalo Rodrigues Pardal, Stewart Williams
Summary: This study proposes an innovative method to accelerate the thermal analysis of the scanning laser (SL) process for additive manufacturing (AM) by reducing the order of the finite element model. The method achieves high accuracy while significantly reducing computational time and element amount. Additionally, the introduction of an equivalent heat source improves computational efficiency. This method can be applied to parametric analysis and optimization of novel AM processes, as well as thermal analyses of large structures AM and other manufacturing processes.
JOURNAL OF MATERIALS PROCESSING TECHNOLOGY
(2023)
Article
Engineering, Manufacturing
Przemyslaw Golebiewski, Pawel Wienclaw, Jaroslaw Cimek, Pawel Socha, Dariusz Pysz, Adam Filipkowski, Grzegorz Stepniewski, Olga Czerwinska, Ireneusz Kujawa, Ryszard Stepien, Rafal Kasztelanic, Andrzej Burgs, Ryszard Buczynski
Summary: We report the development of a 3D printing process for producing soft glass optical fibers. The process involves direct printing using a miniaturized crucible and depositing straight horizontally-oriented lines to replace traditional assembly techniques. Experimental results demonstrate good performance of the printed photonic crystal fiber preform.
ADDITIVE MANUFACTURING
(2024)
