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Acta Metallurgica Sinica(English Letters) 2018年第8期31卷 807-814页

作者： Lin-Zhi Wang Wen-Hou Wei chongqing key laboratory of additive manufacturing technology and systems Chongqing Institute of Green and Intelligent Technology Chinese Academy of Sciences

Three-dimensional parts of the 30 CrMnSiA steel were successfully fabricated using selective laser melting（SLM）. The microstructures and mechanical properties of the SLM-processed 30 CrMnSiA samples were investigated by scanning electron microscope and transmission electron microscopy. The results indicate that the microstructures of the 30 CrMnSiA samples consist mainly of lath martensite and acicular martensite. The value of the surface roughness decreases with increasing laser energy density（LED） before it reaches a minimum and then increases with further increasing LED. The relative density, microhardness and ultimate tensile strength of the SLM-processed samples initially increase and then decrease with increasing LED. By taking the relative density, surface roughness, microhardness and ultimate tensile strength into account, the optimized LED should be in the range of 46.15–51.28 J mm^（-3） for the SLM-processed30 CrMnSiA alloys. In addition, the differences in the microstructures and mechanical properties between the conventionally wrought 30 CrMnSiA sample and SLM-processed 30 CrMnSiA samples were also studied.

关键词： 30CrMnSiA Selective laser melting Laser energy density Microstructure Mechanical properties

Mechanical properties and microstructures of Mg-6Si alloys fabricated using the tungsten-inert-gas arc additive manufacturing

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China Foundry 2025年

作者： Peng-cheng Zhou Guo-qiang You Jin-yu Feng Lei Wang Xiao Lin Bin Jiang College of Materials Science and Engineering Chongqing University National Engineering Research Center for Magnesium Alloys Chongqing University National key laboratory of Advanced Casting Technologies Chongqing University

Si-containing Mg alloys solidified at conventional rates often contain coarse and sharp Mg2Si phases,which can result in inferior material *** this study,Mg-6wt.%Si （Mg-6Si） alloy was prepared by wire arc additive manufacturing （WAAM）,employing the gas tungsten arc welding technique with rapid *** microstructures and mechanical properties of the WAAM alloy were investigated and compared with those of the as-cast samples produced using a metal *** results indicate that the WAAM Mg-6Si is harder and stronger than the as-cast *** microhardness of the WAAM Mg-6Si increases by 36.6%in comparison to that of as-cast Mg-6Si ***,the average tensile strengths at room temperature and 150°C increases by 63.4%and 21.3%,*** refines both the Mg2Si phase and the overall grains,resulting in a homogeneous morphology and improved mechanical *** granular Mg2Si phase,characterized by fine particles with a diffused distribution,shows a significant increase in *** acicular Mg2Si phase is distributed along the grain boundaries,and its concentration significantly *** average grain size of the Mg2Si phase is about 9.20μm,about 5 times *** refinement and distribution of the granular Mg2Si phase,as well as the reduction in the amount of needle-like Mg2Si particles,are the key factors for improving the mechanical properties of WAAM Mg-6Si alloy.

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Multi-layer multi-pass friction rolling additive manufacturing of Al alloy:Toward complex large-scale high-performance components

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International Journal of Minerals,Metallurgy and Materials 2025年第2期32卷 425-438页

作者： Haibin Liu Run Hou Chenghao Wu Ruishan Xie Shujun Chen College of Mechanical&Energy Engineering Beijing University of TechnologyBeijing 100124China chongqing Research Institute of Beijing University of technology Chongqing 401121China

At present,the emerging solid-phase friction-based additive manufacturing technology,including friction rolling additive man-ufacturing(FRAM),can only manufacture simple single-pass *** this study,multi-layer multi-pass FRAM-deposited alumin-um alloy samples were successfully prepared using a non-shoulder tool *** material flow behavior and microstructure of the over-lapped zone between adjacent layers and passes during multi-layer multi-pass FRAM deposition were studied using the hybrid 6061 and 5052 aluminum *** results showed that a mechanical interlocking structure was formed between the adjacent layers and the adja-cent passes in the overlapped center *** friction and rolling of the tool head led to different degrees of lateral flow and plastic deformation of the materials in the overlapped zone,which made the recrystallization degree in the left and right edge zones of the over-lapped zone the highest,followed by the overlapped center zone and the non-overlapped *** tensile strength of the overlapped zone exceeded 90%of that of the single-pass deposition *** is proved that although there are uneven grooves on the surface of the over-lapping area during multi-layer and multi-pass deposition,they can be filled by the flow of materials during the deposition of the next lay-er,thus ensuring the dense microstructure and excellent mechanical properties of the overlapping *** multi-layer multi-pass FRAM deposition overcomes the limitation of deposition width and lays the foundation for the future deposition of large-scale high-performance components.

关键词： aluminum alloy additive manufacturing solid-state friction stir welding multi-layer multi-pass

Mechanical properties and friction behaviors of CNT/AlSi_(10)Mg composites produced by spark plasma sintering

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International Journal of Minerals,Metallurgy and Materials 2017年第5期24卷 584-593页

作者： Lin-zhi Wang Ying Liu Jiao-jiao Wu Xi Zhang chongqing key laboratory of additive manufacturing technology and systems Chongqing Institute of Green and Intelligent TechnologyChinese Academy of Sciences College of Material Science and Engineering Sichuan University College of Material Science and Engineering Southwest Jiaotong university

The mechanical properties and friction behaviors of CNT/AlSi10Mg composites produced by spark plasma sintering (SPS) were investigated. The results showed that the densities of the sintered composites gradually increased with increasing sintering temperature and that the highest microhardness and compressive strength were achieved in the specimen sintered at 450A degrees C. CNTs dispersed uniformly in the Al-Si10Mg matrix when the addition of CNTs was less than 1.5wt%. However, when the addition of CNTs exceeded 1.5wt%, the aggregation of CNTs was clearly observed. Moreover, the mechanical properties (including the densities, compressive strength, and microhardness) of the composites changed with CNT content and reached a maximum value when the CNT content was 1.5wt%. Meanwhile, the minimum average friction coefficient and wear rate of the CNT/AlSi10Mg composites were obtained with 1.0wt% CNTs.

关键词： metal matrix composites carbon nanotubes (CNTs) aluminum silicon magnesium alloys spark plasma sintering mechanical properties friction

Effects of heat treatment on microstructure and mechanical properties of SLMed Sc-modified AlSi10Mg alloy

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Progress in Natural Science:Materials International 2021年第5期31卷 714-721页

作者： Yuming Chen Linzhi Wang Zhongxue Feng Wanneng Zhang Materials Science and Engineering College Kunming University of Science and Technology chongqing key laboratory of additive manufacturing technology and systems Chongqing Institute of Green and Intelligent Technology Chinese Academy of Sciences chongqing School University of Chinese Academy of Sciences

The influence of heat treatments on the microstructures and mechanical properties of the selective laser melting manufactured AlSi10Mg alloy modified with Sc was systematically investigated. The results showed that the addition of Sc element introduced primary Al3Sc, which increased the heterogeneous nucleation during the solidification of AlSi10Mg alloy, and then the ultrafine network eutectic structure was obtained, and hence the tensile strength was improved significantly(nearly 23 %). During the heat treatment process, the network eutectic structure transformed from continuous to discontinuous, and the grain refinement was weakened with an increasing heating temperature, both of which affected the mechanical properties of the Sc modified AlSi10Mg alloy. The tensile strength decreased from 438 ± 10 MPa for the Sc-modified alloy to 208 ± 6 MPa, while the fracture strain significantly increased from 6 ± 0.2 % to 30.2 ± 1.2 % when the Sc-modified alloy was heat-treated at 325°C for 12 h. It has been found that the desirable microstructure and mechanical properties of SLM Scmodified AlSi10Mg alloy can be realized by controlling the heat treatment process parameters.

关键词： Selective laser melting Sc-modified aluminum alloy Mechanical properties Post-processing heat treatment

Selective laser melting of lanthanum oxide-reinforced tungsten composites:microstructure and mechanical properties

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Tungsten 2022年第1期4卷 67-78页

作者： Shen-Yu Wei Li-Na Ji Wen-Jie Wu Hong-Lin Ma chongqing Institute of Green and Intelligent technology Chinese Academy of SciencesChongqing 400714China University of Chinese Academy of Sciences Beijing 100049China chongqing key laboratory of additive manufacturing technology and systems Chongqing 400714China

In this study,La_(2)O_(3)nanoparticles were introduced into the tungsten(W)matrix to optimize the microstructure and properties of pure *** W-La_(2)O_(3)composites with different mass ratios of La_(2)O_(3)were manufactured by selective laser melting(SLM).The result showed that the average grain sizes for W-1 wt%La_(2)O_(3)and W-2 wt%La_(2)O_(3)were reduced by more than 51.3%compared with that of pure W,and the defects obviously *** microhardness and compressive strength of the SLM W-2 wt%La_(2)O_(3)sample reached 455 HV and 2194 MPa,*** toughness of the SLM W-2 wt%La_(2)O_(3)sample also improved *** main reason was that the La_(2)O_(3)nanoparticles provide many heterogeneous nucleation sites to refine the *** other main reason was that La_(2)O_(3)nanoparticles formed into dislocation loops,which hindered the movement of dislocations and then increased the strength *** research provided a new method to improve the mechanical properties of SLM W by introducing La_(2)O_(3)nanoparticles to achieve fine-grains strengthening and Orowan strengthening.

关键词： Selective laser melting W-La_(2)O_(3)composites Cracks Mechanical properties

A density functional theory study of methane activation on MgO supported Ni_(9)M_(1) cluster:role of M on C-H activation

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Frontiers of Chemical Science and Engineering 2022年第10期16卷 1485-1492页

作者： Juntian Niu Haiyu Liu Yan Jin Baoguo Fan Wenjie Qi Jingyu Ran College of Electrical and Power Engineering Taiyuan University of TechnologyTaiyuan 030024China key laboratory of Advanced manufacturing technology for Automobile Parts Ministry of EducationChongqing University of TechnologyChongqing 400050China key laboratory of Low-grade Energy Utilization Technologies and systems Ministry of EducationChongqing UniversityChongqing 400044China

Methane activation is a pivotal step in the application of natural gas converting into high-value added chemicals via methane steam/dry reforming *** element was found to be the most widely used *** present work,methane activation on MgO supported Ni–M(M=Fe,Co,Cu,Pd,Pt)cluster was explored through detailed density functional theory calculations,compared to pure Ni ***_(4)adsorption on Cu promoted Ni cluster requires overcoming an energy of 0.07 eV,indicating that it is slightly endothermic and unfavored to occur,while the adsorption energies of other promoters M(M=Fe,Co,Pd and Pt)are all higher than that of pure Ni *** role of M on the first C–H bond cleavage of CH_(4)was *** elements of the same period in Ni cluster,such as Fe,Co and Cu,for C–H bond activation follows the trend of the decrease of metal atom *** a result,Ni–Fe shows the best ability for C–H bond *** addition,doping the elements of the same family,like Pd and Pt,for CH_(4)activation is according to the increase of metal atom ***,C–H bond activation demands a lower energy barrier on Ni–Pt *** illustrate the adsorptive dissociation behaviors of CH_(4)at different Ni–M clusters,the Mulliken atomic charge was *** general,the electron gain of CH_(4)binding at different Ni–M clusters follows the sequence of Ni–Cu(–0.02 e)

关键词： CH_(4) dissociation Ni-M C-H bond activation charge transfer

Selective laser melting of magnesium alloys: Necessity, formability, performance, optimization and applications

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Journal of Materials Science & technology 2023年第23期154卷 65-93页

作者： Kun Li Chen Ji Shengwen Bai Bin Jiang Fusheng Pan State key laboratory of Mechanical Transmission Chongqing University Chongqing 400044 China chongqing key laboratory of Metal additive manufacturing (3D Printing) Chongqing University Chongqing 400044 China College of Mechanical and Vehicle Engineering Chongqing University Chongqing 400044 China National Engineering Research Center for Magnesium Alloys College of Materials Science and Engineering Chongqing University Chongqing 400044 China

Selective laser melting (SLM), as a rapid prototyping technology, has been widely used to manufacture high-performance metal components with complex structures, which vitally provides a broad platform for the development and application of magnesium alloys. However, the poor laser formability of magnesium alloys has deleterious consequences in the application of SLM processing. This paper discusses the defect formation mechanisms during the SLM process and summarizes characteristics in terms of mechanical properties, oxidation and corrosion resistance. Current optimization schemes are reviewed from both macro and micro perspectives. Firstly, the relationship between process parameters and formability and material properties is clarified, and advanced optimization methods of the design of experiments, physical models, and machine learning are evaluated. Secondly, the effects of alloying elements, composite reinforcement, and post-treatment on the microstructure and properties of the SLMed magnesium alloy are reviewed. Finally, the future application development prospects are envisaged based on the comprehensive review. This work is significantly helpful to a better scientific understanding of SLMed magnesium alloy and puts forward some meaningful guiding opinions for the future work of magnesium alloy manufacturing.

关键词： Magnesium alloys Selective laser melting Defects Microstructure-property relationship Performance optimization

A facile strategy of in-situ anchoring of Co_(3)O_(4) on N doped carbon cloth for an ultrahigh electrochemical performance

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Nano Research 2021年第7期14卷 2410-2417页

作者： Junlin Lu Jien Li Jing Wan Xiangyu Han Peiyuan Ji Shuang Luo Mingxin Gu Dapeng Wei Chenguo Hu chongqing key laboratory of Soft Condensed Matter Physics and Smart Materials Department of Applied PhysicsChongqing UniversityChongqing 400044China key laboratory of Multi-Scale manufacturing technology Chongqing Institute of Green and Intelligent TechnologyChinese Academy of SciencesChongqing 400714China

Enhancement of supercapacitors(SCs)with high-energy density and high-power density is still a great *** this paper,a facile strategy for in situ anchoring of Co_(3)O_(4) particles on N doped carbon cloth(pCoNCC)is *** to the interaction of the doped N and Co_(3)O_(4),the electrochemical performance improves significantly,reaching 1,940.13 mF·cm^(−2) at 1 mA·cm^(−2) and energy density of 172.46μWh·cm^(−2) at the power density of 400μW·cm^(−2),much larger than that without N doping electrode of 28.5 mF·cm^(−2).An aqueous symmetric supercapacitor(ASSC)assembled by two pCoNCC electrodes achieves a maximum energy density of 447.42μWh·cm^(−2) and a highest power density of 8,000μW·cm^(−2).Utilizing such a high-energy storage ASSC,a digital watch and a temperature-humidity detector are powered for nearly 1 and 2 h,***,the ASSC displays a superb electrochemical stability of 87.7%retention after 10,000 cycles at 40 mA·cm^(−2).This work would provide a new sight to enhance active materials performance and be beneficial for the future energy storage and supply systems.

关键词： Co_(3)O_(4) N doping carbon cloth supercapacitor

Flexible and transparent triboelectric nanogenerator based on high performance well-ordered porous PDMS dielectric film

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Nano Research 2016年第12期9卷 3714-3724页

作者： Xianming He Xiaojing Mu Quan Wen Zhiyu Wen Jun Yang Chenguo Hu Haofei Shi Department of Applied Physics Chongqing University Chongqing 400044 China key laboratory of Fundamental Science of Micro/Nano-Device and System technology Chongqing University Chongqing 400044 China Microsystem Research Center Chongqing University Chongqing 400044 China key laboratory of Multi-Scale manufacturing technology Chongqing Institute of Green and Intelligent Technology Chinese Academy of Sciences Chongqing 400714 China

A flexible and transparent triboelectric nanogenerator （FT-TENG） has great potential for application in self-powered biosensor systems, electronic skin and wearable electronic devices. However, improving the output performance with little damage to its optical properties is challenging. Herein, we have developed an FT-TENG that has a well-ordered nest-like porous polydimethylsiloxane （NP-PDMS） film and graphene transparent electrodes. The NP-PDMS film with ordered pores is fabricated by hydrochloric acid etching of 500 nm sized ZnO spheres made of aggregated nanoparticles, having a light transmittance of 81.8% and a water contact angle of 118.62°. The FT-TENG based on the NP-PDMS film with a porosity of 12%, gives a maximum output of 271 V and 7.8 μA, which are respectively, 3.7 and 2.1-fold of those of a TENG with a flat PDMS film. The peak output power reaches 0.39 mW with a load resistance of 9.01 MΩ. The dielectric constant and effective thickness of the NP-PDMS film and the capacitance and charge transfer of the FT-TENG are systematically investigated. This work provides a novel and effective method to enhance the performance of FT-TENGs with little damage to their optical properties.

关键词： porouspolydimethylsiloxane(PDMS) surface charge density nanogenerator flexibility transparent electrode