Additive manufacturing(AM),recognized as a pivotal innovation,has revolutionized the manufacturing industry since its inception.With a robust background of over three decades in AM,China has accomplished significant m...Additive manufacturing(AM),recognized as a pivotal innovation,has revolutionized the manufacturing industry since its inception.With a robust background of over three decades in AM,China has accomplished significant milestones,emerging as a key global player in the deployment and export of related machinery and products.China’s prominence within the realm of powder bed fusion technology is underscored by its substantial market share.Electron beam powder bed fusion(EB-PBF),known for its low residual stress and high forming efficiency,has gained considerable international interest.Since Tsinghua University initiated the first research on EB-PBF in 2004,China has steadily advanced in this area,leading to the commercialization of EB-PBF devices and the development of a diverse product line.This comprehensive review highlights the research progress in EB-PBF,focusing on its development in China,explores novel technologies,and offers insights into future advancements.展开更多
TiAl alloys fabricated by electron beam powder bed fusion(EB-PBF)usually exhibit special microstructures with alternating fine-grained(FG)regions and coarse-grained(CG)bands.In previous studies,the CG microstructures ...TiAl alloys fabricated by electron beam powder bed fusion(EB-PBF)usually exhibit special microstructures with alternating fine-grained(FG)regions and coarse-grained(CG)bands.In previous studies,the CG microstructures were equiaxed γ phases,and the FG microstructures presented three types:near gamma,duplex,and nearly lamellar.However,the rule for controlling FG microstructures has not been found.Hence,a method needs to be built to find the rule for controlling FG microstructures.Here,we established a normalized process diagram by combining Al-equivalent and dimensionless process parameters.Based on the normalized process diagram,we successfully control the FG microstructures and customize three FG microstructures of the Ti-48Al-2Cr-2Nb alloy.Meanwhile,the average tensile yield strength reaches 756 MPa when the FG microstructure is near gamma.The yield strength is higher than the previous data for the Ti-48Al-2Cr-2Nb alloy.This is attributed to the strong interface-strengthening effect between FG near γ microstructures and CG γ bands.These findings can help shorten the research time of the other TiAl alloys fabricated by EB-PBF,improving the mechanical properties of the other EBPBF-built TiAl alloys in the future.展开更多
The field of printed electronics has been extensively researched for its versatility and scalability in flexible and large-area applications.Impedance is of great importance for the performance and reliability of elec...The field of printed electronics has been extensively researched for its versatility and scalability in flexible and large-area applications.Impedance is of great importance for the performance and reliability of electronics.However,its measurement requires electrical contacts,which makes it difficult on complex or bio-interfaces.Although the printing process is accessible,impedance characterization may be cumbersome,which can create a bottleneck during the manufacturing process.This paper reports the first effort at developing a convolutional neural network(CNN)based image regression model to replace impedance spectroscopy(IS).In our study,the CNN model learned the features of inkjet-printed electrode images that are dependent on the printing and sintering of nanomaterials and quantitatively predicted the resistance and capacitance of the equivalent circuit of the inkjet-printed lines.The image-based impedance spectroscopy(IIS)is expected to be the cornerstone as a revolutionary approach to electronics research and development enabled by deep neural networks.展开更多
电子束选区熔化成形技术(Selective Electron Beam Melting,SEBM),是20世纪90年代中期发展起来的一类新型增材制造技术,具有能量利用率高、无反射、功率密度高、扫描速度快、真空环境无污染、低残余应力等优点,特别适合活性、难熔、脆...电子束选区熔化成形技术(Selective Electron Beam Melting,SEBM),是20世纪90年代中期发展起来的一类新型增材制造技术,具有能量利用率高、无反射、功率密度高、扫描速度快、真空环境无污染、低残余应力等优点,特别适合活性、难熔、脆性金属材料的直接成形,在航空航天、生物医疗、汽车、模具等领域具有广阔的应用前景。10年来,作者团队主要开展SEBM成形钛合金的研究,合金包括TC4、TA7、Ti600、Ti Ta Nb Zr、Ti Al金属间化合物等;零件包括复杂薄壁、桁架/多孔及多孔/致密复合结构零件;并且搭建了从粉末制备、设备研发到技术服务的全产业链SEBM技术平台,通过科技成果转化成立了从事SEBM技术的专业化企业——西安赛隆金属材料有限责任公司。从成形装备、成形过程缺陷形成与控制、材料组织性能和主要应用4个方面,对国内外SEBM技术的发展现状进行了综述,最后对SEBM技术的发展前景进行了展望。展开更多
基金supported by Defense Industrial Technology De-velopment Program(Grant No.JCKY2023110A003)National Science and Technology Major Project of China(Grant No.J2019-VII-0016-0156)+1 种基金NSFC(National Natural Science Foundation of China)-DFG(Deutsche Forschungsgemeinschaft)Joint Research Program(Grant No.52061135113)NSFC Original Exploration Program Projects and Continuing Funding Projects(Grant Nos.52250009,52050110).
文摘Additive manufacturing(AM),recognized as a pivotal innovation,has revolutionized the manufacturing industry since its inception.With a robust background of over three decades in AM,China has accomplished significant milestones,emerging as a key global player in the deployment and export of related machinery and products.China’s prominence within the realm of powder bed fusion technology is underscored by its substantial market share.Electron beam powder bed fusion(EB-PBF),known for its low residual stress and high forming efficiency,has gained considerable international interest.Since Tsinghua University initiated the first research on EB-PBF in 2004,China has steadily advanced in this area,leading to the commercialization of EB-PBF devices and the development of a diverse product line.This comprehensive review highlights the research progress in EB-PBF,focusing on its development in China,explores novel technologies,and offers insights into future advancements.
基金financially supported by the National Science Foundation of China(Nos.92163215,52305379,52322101,52174364,52101143,51771093,and 12202201)the Fundamental Research Funds for the Central Universities(Nos.30922010202,and 30922010711)+4 种基金the Key Laboratory Funds for the Science and Technology of National Defense(No.6142212210103)the Natural Science Foundation of Jiangsu Province Major Project(No.BK20212009)the Xi’an Qinchuangyuan Construction of Two-Chain Integration Major Special Projects(No.23LLRHZDZX0015)the Aviation Science Foundation of AVIC(No.2024M0530S8002)the Natural Science Basic Research Program of Shaanxi Province(No.2024JC-YBQN-0579).
文摘TiAl alloys fabricated by electron beam powder bed fusion(EB-PBF)usually exhibit special microstructures with alternating fine-grained(FG)regions and coarse-grained(CG)bands.In previous studies,the CG microstructures were equiaxed γ phases,and the FG microstructures presented three types:near gamma,duplex,and nearly lamellar.However,the rule for controlling FG microstructures has not been found.Hence,a method needs to be built to find the rule for controlling FG microstructures.Here,we established a normalized process diagram by combining Al-equivalent and dimensionless process parameters.Based on the normalized process diagram,we successfully control the FG microstructures and customize three FG microstructures of the Ti-48Al-2Cr-2Nb alloy.Meanwhile,the average tensile yield strength reaches 756 MPa when the FG microstructure is near gamma.The yield strength is higher than the previous data for the Ti-48Al-2Cr-2Nb alloy.This is attributed to the strong interface-strengthening effect between FG near γ microstructures and CG γ bands.These findings can help shorten the research time of the other TiAl alloys fabricated by EB-PBF,improving the mechanical properties of the other EBPBF-built TiAl alloys in the future.
基金supported by the Ministry of Education through the Basic Science Research Program through the National Research Foundation of Korea(NRF-2021R1I1A3059714)by the Korea Institute of Industrial Technology as"Development of root technology for multi-product flexible production(KITECH EO-24-0009)+1 种基金supported by project for Collabo R&Dbetween Industry,University,and Research Institute funded by Korea Ministry of SMEs and Startups in 2023(RS-2023-00224114)supported by the faculty research fund of Sejong University in 2024。
文摘The field of printed electronics has been extensively researched for its versatility and scalability in flexible and large-area applications.Impedance is of great importance for the performance and reliability of electronics.However,its measurement requires electrical contacts,which makes it difficult on complex or bio-interfaces.Although the printing process is accessible,impedance characterization may be cumbersome,which can create a bottleneck during the manufacturing process.This paper reports the first effort at developing a convolutional neural network(CNN)based image regression model to replace impedance spectroscopy(IS).In our study,the CNN model learned the features of inkjet-printed electrode images that are dependent on the printing and sintering of nanomaterials and quantitatively predicted the resistance and capacitance of the equivalent circuit of the inkjet-printed lines.The image-based impedance spectroscopy(IIS)is expected to be the cornerstone as a revolutionary approach to electronics research and development enabled by deep neural networks.
文摘电子束选区熔化成形技术(Selective Electron Beam Melting,SEBM),是20世纪90年代中期发展起来的一类新型增材制造技术,具有能量利用率高、无反射、功率密度高、扫描速度快、真空环境无污染、低残余应力等优点,特别适合活性、难熔、脆性金属材料的直接成形,在航空航天、生物医疗、汽车、模具等领域具有广阔的应用前景。10年来,作者团队主要开展SEBM成形钛合金的研究,合金包括TC4、TA7、Ti600、Ti Ta Nb Zr、Ti Al金属间化合物等;零件包括复杂薄壁、桁架/多孔及多孔/致密复合结构零件;并且搭建了从粉末制备、设备研发到技术服务的全产业链SEBM技术平台,通过科技成果转化成立了从事SEBM技术的专业化企业——西安赛隆金属材料有限责任公司。从成形装备、成形过程缺陷形成与控制、材料组织性能和主要应用4个方面,对国内外SEBM技术的发展现状进行了综述,最后对SEBM技术的发展前景进行了展望。
