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Negative thermal expansion in metamaterials made from 4D printed Cu–Al–Ni alloy

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Journal of Materials Research and technology 2025年 37卷 2005-2021页

作者： Daniyal Abolhasani Wook Jin Lee Young Hoon Moon Center for Innovative Technology on Advanced Forming School of Mechanical Engineering Pusan National University Busan 46241 Republic of Korea School of Material Science and Engineering Pusan National University Busan 46241 Republic of Korea

The materials used in precision instruments need to withstand temperature variations that causes dimensional variations due to thermal expansion (TE). To address this issue, mechanical metamaterials made from two materials with different TE have been proposed. However, fabricating such structures using additive manufacturing is challenging because it requires the simultaneous operation of two lasers or nozzles. advanced materials, such as shape memory alloys (SMA)s, can achieve negative thermal expansion (NTE) through modifications in composition and microstructure, but their development is typically limited to single components. In pursuit of this objective, this study aims to provide valuable insights into the relationship between the shape memory effect (SME) and unit cells designed with straight (stretching-dominated) and curved (bending-dominated) beams at various angles between the beams (2β) ranging from 40° to 60°. The focus is on how these designs impact dimensional variations for NTE applications. NTE lattices made of high-temperature Cu–Al–Ni SMA were subjected to a thermal load of 400 K. The results indicated that larger angles in straight beams led to a softening effect, reducing the SME and size stability. In contrast, curved beams at larger angles demonstrated stable SME and maintained size stability due to the influence of bending moments and the reorientation of martensite. For beams at lower angles, heat radiation initially improved SME and size stability by promoting the reversion of remnant martensite back into austenite. However, the stress gradients in cells with curved beams at these angles resulted in twin disconnection, leading to decreased SME and size stability.

关键词： Metamaterial Negative thermal expansion Shape memory effect Cu–Al–Ni 4d printing

Engineering design of feedstock powder and relevant thermal-mechanical performance of thermal/environmental barrier coatings

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Journal of advanced Ceramics 2025年第2期14卷 37-56页

作者： Xinchang Feng Fangwei Guo Lirong Luo Yuzhang Wang Yun Long Xiaofeng Zhao Fei Pan Lei Guo Qingfeng Zeng Jing Feng Chunlei Wan Shanghai Key Laboratory of Advanced High-temperature Materials and Precision Forming School of Materials Science and EngineeringShanghai Jiao Tong UniversityShanghai 200240China National Engineering Research Center of Special Equipment and Power System for Ship and Marine Engineering Shanghai 200030China School of Mechanical Engineering Shanghai Jiao Tong UniversityShanghai 200240China State Key Laboratory of Advanced Nuclear Energy Technology Nuclear Power Institute of ChinaChengdu 610213China Innovative Sensor Technology IST AG Ebnat-Kappel 9642Switzerland School of Materials Science and Engineering Tianjin UniversityTianjin 300072China Tianmushan Laboratory Hangzhou 311115China School of Materials Science and Engineering Kunming University of Science and TechnologyKunming 650093China State Key Laboratory of New Ceramics and Fine Processing School of Materials Science and EngineeringTsinghua UniversityBeijing 100084China

The development of aeroengine with a high thrust-weight ratio poses great challenges for current top-coating thermal barrier coatings (TBCs) and environmental barrier coatings (EBCs) in service. Medium/high-entropy ceramics are highly promising candidate material for advanced TBCs/EBCs owing to their low thermal conductivity, high melting point, high-temperature stability, and calcium–magnesium–alumino–silicate (CMAS) resistance. Most feedstock powder used for medium/high-entropy TBCs/EBCs is prepared via traditional spray drying, which cannot fully exploit the advantages of multicomponent ceramics. The density, sphericity, inner structure, and flowability of feedstock powder affect their melting state during the thermal spraying process, which strongly affects the microstructure and properties of the deposited coatings. Therefore, the deposited coatings exhibit phase segregation, amorphous phases, and microstructure defects owing to unpredictable variations in feedstock powder with random morphologies and structures. Here, the structure and properties of feedstock powder prepared by state-of-the-art granulation technologies and their influences on the deposited coatings were systematically investigated, which can provide guidance for configuration optimization of feedstock powder and the manufacturing accuracy of the deposited coating. This review aims to bridge the gap between cutting-edge ceramics and advanced engineering technologies, thus providing concrete background knowledge and crucial guidelines for designing and developing TBCs/EBCs.

关键词： thermal/environmental barrier coatings(TBCs/EBCs) spraying ceramic powder multiscale structure control high-entropy ceramics thermal-mechanical performance

4d-Printed Niti Auxetic Metamaterial with Enhanced Functionality Via Deposition of Nano-Ni Layer

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SSRN 2024年

作者： Abolhasani, Daniyal Lee, Wookjin VanTyne, Chester J. Moon, Young Hoon Center for Innovative Technology on Advanced Forming School of Mechanical Engineering Pusan National University Busan46241 Korea Republic of School of Material Science and Engineering Pusan National University Busan46241 Korea Republic of Department of Metallurgical and Materials Engineering Colorado School of Mines GoldenCO80401 United States

The aerospace and energy conversion industries utilize superelastic metallic metamaterials fabricated by additive manufacturing (AM). Currently, printing samples with "residual particle-free" surfaces requires post-cleaning techniques such as chemical and electrochemical etching. However, the high concentration of stress and cracking near the nodes and sharp edges can cause brittle fracture, strength reduction, and energy absorption. Moreover, topological optimization can significantly increase the weight of a structure. To overcome these challenges, in this study, we utilized the benefits of multicomponent structures and nanomaterials possessing high capillary effects and low melting points. Specifically, a thin layer of nano-Ni was deposited on the surfaces of NiTi auxetic structures printed using micro-Ni–Ti powders. The results showed that high-performance functional structures with reliable surfaces, high strength, high energy absorption, and constant Poisson’s ratios for a given deformation could be achieved. This was attributed to a low stress-induced martensite formed during laser processing and a low residual stress, computed experimentally and by simulations. Although the loss factor or dissipated energy during superelastic cycling was enhanced, the superelastic reproducibility was lowered in the samples fabricated using the developed method. This was attributed to the higher strain hardening and dislocation generation, despite the developed approach resulting in a very high superelastic recovery in the initial cycles. The findings of this study provide a framework for designing high-performance functional structures using AM and nanomaterials for energy-absorbing devices with high resistance to vibration. © 2024, The Authors. All rights reserved.

关键词： Binary alloys

High-Performance Cu-Al Shape Memory Alloy in Ternary Combination with Graphene Fabricated by Powder Bed Fusion Process

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SSRN 2023年

作者： Abolhasani, Daniyal Moon, Byungrok Kang, Namhyun VanTyne, Chester J. Moon, Young Hoon Center for Innovative Technology on Advanced Forming School of Mechanical Engineering Pusan National University Busan46241 Korea Republic of School of Material Science and Engineering Pusan National University Busan46241 Korea Republic of Department of Metallurgical and Materials Engineering Colorado School of Mines GoldenCO80401 United States

The main characteristic feature of Cu-based high-temperature shape memory alloys (SMAs) such as Cu-Al-Ni alloys is their high transformation temperatures that enable their applications at high temperatures. The improvement of thermodynamic properties of SMAs with reinforcements is essential for more applications at high temperatures with fewer negative effects of exposure at high temperatures, such as alloy softening that can deteriorate the strength and shape memory effect (SME) simultaneously. To avoid the negative effects of micro-reinforcements such as stress localization, in this study, graphene (GN) was substituted with Ni, and a new alloy labeled Cu-Al-GN with 0.2 wt% graphene was formed. A graphene-reinforced alloy labeled Cu-Al-Ni-GN was also fabricated by a laser powder bed fusion process for comparison purposes. The results showed that the Cu-Al-GN alloy exhibited enhanced performance in terms of improved reinforcement distribution, finer grains, defect-free samples with the highest SME at subsequent cycles, and less time required to achieve a targeted SME during heating, despite the smaller SME in the initial recovery cycles. Thus, the results of this study confirm that the proposed Cu-Al-0.2GN alloy combination promises high performance for recovery cycles and is time and cost saving, rendering it a suitable candidate for rapid production. © 2023, The Authors. All rights reserved.

关键词： Ternary alloys

Powder Bed Fusion of Two-Functional Cu-Al-Ni Shape Memory Alloys Utilized for 4d Printing

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SSRN 2022年

作者： Abolhasani, Daniyal Han, Sang Wook VanTyne, Chester J. Kang, Namhyun Moon, Young Hoon Center for Innovative Technology on Advanced Forming School of Mechanical Engineering Pusan National University Busan46241 Korea Republic of Department of Metallurgical and Materials Engineering Colorado School of Mines GoldenCO80401 United States Department of Materials Science and Engineering Korea Republic of

Transforming a 3D-printed part into a pre-programmed shape over time is called four-dimensional (4D) printing. Shape memory alloy (SMA) is most commonly used material for 4D printing. However, metal-based SMAs exhibit lower recovered strain during 4D printing compared to shape memory polymers, thereby requiring enhanced recovery in metal-based SMAs. In this study, a novel two-functional Cu-Al-Ni SMA consisting of two separate structures fabricated by powder bed fusion process was investigated to enhance the recovery in SMAs. The binding morphology of the two structures and subsequent consequences on the 4D printing behavior were analyzed. The first structure recovered at a lower temperature, whereas the second structure recovered at a higher temperature. In the case of the two-functional material, the difference in the hardness values and recovery temperature favored the recovered deformation due to the damping behavior of the harder structure and the generation of a temperature gradient across the deformation section. Additionally, the higher residual stresses obtained in the harder structure by simulation proved the mismatch between the two structures, leading to resistance against plastic deformation. Meanwhile, the formation of secondary martensite plates was observed in the second structure of the two-functional material. These secondary martensite plates enhanced the overall recovery by (i) the attenuation of thermal conductivity across the deformation section and generation of the temperature gradient, and (ii) the increase in residual stresses and mismatch between the two joined structures. © 2022, The Authors. All rights reserved.

关键词： Nickel alloys

Feasibility of Using Graphene as a Substitute to Graphite in the Laser Surface Hardening of Ferritic Stainless Steel

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SSRN 2022年

The broad potential applications of ferritic stainless steel in industry can be increased with the addition of protective elements such as carbon for surface hardening. Laser cladding (LC) using carbon elements, such as graphite, has received widespread attention. However, to obtain high quality results, the use of graphite slurry, a specific environment, or remelting are required. To overcome this challenge, the LC of graphene as an alternative to graphite was studied in this work. Accordingly, the stability of cladding layers, which depicts their sustainability in actual environmental conditions, was compared in graphene, graphite, and their slurries to improve the evaluation of graphene in the LC process. The stability of cladding layers predominantly depends on the clad hardness, crack susceptibility, interfacial stress, hardness depth (or aspect ratio), and interfacial hardness. Under suitable process conditions, graphene exhibits good stability, with the highest clad hardness and low stress fluctuation without crack formation at the interface without remelting. Moreover, considering graphene modification in LC by increasing the aspect ratio and hardness in the area near the interface, the powder layer thickness and laser power can be adjusted to achieve maximum improvements in the aspect ratio and microhardness of approximately 0.26 and 1,000 HV, respectively. Thus, the results of this study demonstrate good feasibility for the laser hardening process in obtaining high microhardness and a crack-free cladding layer without additional remelting or the use of a slurry. © 2022, The Authors. All rights reserved.

关键词： Molecular dynamics

Feasibility of Using Graphene as a Substitute to Graphite in the Laser Surface Hardening of Ferritic Stainless Steel

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SSRN 2022年

关键词： Molecular dynamics

Medical Additive Manufacturing: From a Frontier technology to the Research and Development of Products

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Engineering 2020年第11期6卷 1217-1221页

作者： Guixing Qiu Wenjiang Ding Wei Tian Ling Qin Yu Zhao Lianmeng Zhang Jian Lu Daijie Chen Guangyi Yuan Chengtie Wu Bingheng Lu Ruxu Du Jimin Chen Mo Elbestawi Zhongwei Gu Dichen Li Wei Sun Yuanjin Zhao Jie He Dadi Jin Bin Liu Kai Zhang Jianmo Li Kam WLeong Dewei Zhao Dingjun Hao Yingfang Ao Xuliang Deng Huilin Yang ShaoKeh Hsu Yingqi Chen Long Li Jianping Fan Guohui Nie Yun Chen Hui Zeng Wei Chen Yuxiao Lai Department of Orthopedics Peking Union Medical College HospitalChinese Academy of Medical Science 8 Peking Union Medical CollegeBejjing 100730.China National Engineering Research Center of Light Alloys Net Forming&State Key Laboratony of Metal Matrix Composite Shanghai Jiao Tong UniversityShanghai 200240China Notional Engineering Research Center of Mg Materials and Applicarions and School of Materials Science 8r Engineering.Shanghai Jlao Tong University Shanghai 200240China Department of Spine Surgery Beijing Jishuitan HospitalBeijing 100035China Center for Troanslational Medicine Research and Development Institute of Biomedical and Health EngineeringShenzhen Insitute of Advanced Technology.Chinese Academy of SciencesShenzhen 518055China Guangdong Engineering Laboratony of Biomaterials Additive Manufacturing Guangdong 518055China Musculoskeletal Research Laboratory of the Department of Orthopedics 8 Traumatology and Innovative Orthopedic Biomaterial and Drug Translational Research Laboratory Li Ka Shing Institute of Health SciencesThe Chinese University of Hong KongHong Kong 999077.China State Key Laboratory of Advanced Technology for Materials Synthesis and Processing Wuhan University of TechnologyWuhan 430070China Center for Advanced Structural Materials City University of Hong Kong Shenzhen Research InstiuteShenzhen 518057.China Hong Kong Branch of National Precious Metals Material Engineering Research Center Department of Material Science and EngineeringCity Untiversity of Hong KongHong Kong 999077.China Department of Mechanical Engineering ity Untiversity of Hong Kong.Hong Kong 9977 China School of Pharmacy.Shanghai Jiao Tong University Shanghai 200240China China State Instute of Pharmaceutical Industry Shanghai Institute of Pharmaceutical IndustryShonghai 201203China Shanghai Innovation Instinute for Materials Shanghai 200444.China State Key Laboratory of High-Performance Ceramies and Superfine Microstructure Shanghai Institute of CeramicsChinese Acadermy 0f SciencesShanghai 200050Ch

*** and development(R&D)and the challenges of raw materials for medical additive manufacturing Raw materials for medical additive manufacturing have a wide range of commonalities that are also seen in many other fields,making them an important basis in the field of three-dimensional(3D)*** and challenges related to material types,powder properties,formability,viscoelasticity,and so forth also share common *** example,many metal materials are used in the field of aviation,while metals,polymers,and inorganic materials are used in the field of *** most widely used materials in biomedicine are *** homogeneous and non-homogeneous composites are also available for 3D printing,and impose an additional challenge in additive manufacturing;the use of heterogeneous composites in 3D printing is particularly challenging.

关键词： composites printing additive

Investigation on process parameters of flexible stretch forming process using orthogonal experiment design

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AIP Conference Proceedings 2013年第1期1567卷 1093-1097页

作者： Pan Liu Tae-Wan Ku Jeong Kim Beom-Soo Kang Department of Aerospace Engineering Pusan National University Busan 609-735 Republic of Korea Engineering Research Center of Innovative Technology on Advanced Forming Pusan National University Busan 609-735 Republic of Korea

The flexible stretch forming process (FSFP), is useful sheet metal forming method to produce the small batch three dimensional surfaces. Elastic recovery is one of the very important factors to influence the shape accuracy. The main purpose of this paper is to investigate the influence of design parameters on the elastic recovery. The prestrain, the punch size, the objective radius of surface and thickness of the elastic pad are selected as the design parameters. The value of elastic recovery is selected to evaluate the shape accuracy. The orthogonal experiment design is adopted to investigate the relationship between shape accuracy and design parameters. The analysis of variances (ANOVA) is applied to analyze the value of elastic recovery. The optimal combination is PS3R3PR2T2, which is 0.01 for the prestrain, 500mm for the objective surface radius, 10mm for punch radius and 5mm for elastic pad thickness. The orthogonal experiment design and ANOVA approach may provide a useful guidance to determine design parameters and improve the forming quality in FSFP.

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