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CuPbBi_(5)S_(9) thermoelectric material with an intrinsic low thermal conductivity:Synthesis and properties

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Journal of Materiomics 2022年第1期8卷 174-183页

作者： Hao Liang Jun Guo Yun-Xuan Zhou Zi-Yuan Wang Jing Feng Zhen-Hua Ge Faculty of Materials Science and Engineering Kunming University of Science and TechnologyKunming650093China

CuPbBi_(5)S_(9) compounds have been investigated as gladite for ***,there have been no significant studies on their physical and chemical *** work demonstrates that upon alloying with moderate Cu,Pb,Bi,and S using an appropriate preparation method,quaternary CuPbBi_(5)S_(9) compounds can exhibit excellent figure of merit ZT within the temperature range 298-723 K.A low average velocity,low Young’s modulus and Debye temperature,and large Grüneisen parameter,determined experimentally,indicate strong lattice anharmonicity in CuPbBi_(5)S_(9) ***,density functional theory calculations(local vibration of low-frequency acoustic phonons)justify the low lattice thermal conductivity of CuPbBi_(5)S_(9) *** of the low thermal conductivity(0.514 W m^(-1)K^(-1))and a relatively high power factor(293 μW m^(-1)K^(-2)),a maximum ZT of 0.42 was achieved at 723 K for CuPbBi_(5)S_(9) prepared by mechanical alloying combined with solid-state ***,CuPbBi_(5)S_(9) materials are promising candidates for use as high-performance thermoelectric materials in the intermediate-temperature range.

关键词： CuPbBi_(5)S_(9) Elastic properties Phonon spectrum low thermal conductivity

Extremely low thermal conductivity from bismuth selenohalides with 1D soft crystal structure

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Science China Materials 2020年第9期63卷 1759-1768页

作者： Dongyang Wang Zhiwei Huang Yang Zhang Lijie Hao Guangtao Wang Sihao Deng Hongliang Wang Jie Chen Lunhua He Bao Xiao Yadong Xu Stephen J.Pennycook Haijun Wu Li-Dong Zhao School of Materials Science and Engineering Beihang UniversityBeijing 100191China State Key Laboratory for Mechanical Behavior of Materials Xi’an Jiaotong UniversityXi’an 710049China Instrumental Analysis Center of Xi’an Jiaotong University Xi’an Jiaotong UniversityXi’an 710049China Department of Materials Science and Engineering National University of SingaporeSingapore 117575Singapore Department of Nuclear Physics Neutron Scattering LaboratoryChina Institute of Atomic EnergyBeijing 102413China School of Physics Henan Normal UniversityXinxiang 453007China Spallation Neutron Source Science Center Dongguan 523803China Beijing National Laboratory for Condensed Matter Physics Institute of PhysicsChinese Academy of SciencesBeijing 100190China Songshan Lake Materials Laboratory Dongguan 523808China State Key Laboratory of Solidification Processing Northwestern Polytechnical UniversityXi’an 710072China

Materials with intrinsically low thermal conductivity are of fundamental *** we report a new sort of simple one-dimensional(1 D)crystal structured bismuth selenohalides(Bi Se X,X=Br,I)with extremely low thermal conductivity of^0.27 W m^-1K^-1 at 573 *** mechanism of the extremely low thermal conductivity in 1 D Bi Se X is elucidated systematically using the first-principles calculations,neutron powder-diffraction measurements and temperature tunable aberration-corrected scanning transmission electron microscopy(STEM).Results reveal that the1 D structure of Bi Se X possesses unique soft bonding character,low phonon velocity,strong anharmonicity of both acoustic and optical phonon modes,and large off-center displacement of Bi and halogen ***,all these features contribute to the minimal phonon *** findings provide a novel selection rule to search low thermal conductivity materials with potential applications in thermoelectrics and thermal barrier coatings.

关键词： low thermal conductivity 1D bulk material bismuth selenohalides first-principles calculations

Preparation,Performance and Slag Resistant Mechanism of low thermal conductivity Microporous Corundum

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China's Refractories 2015年第4期24卷 23-30页

作者： FU Lyuping HUANG Ao GU Huazhi ZHANG Meijie LI Zhengkun ZHAO Yi The State Key Laboratory of Refractories and Metallurgy Wuhan University of Science and Technology Jiangsu Jingxin New Material Co. Ltd. Zhejiang Zili Co. Ltd.

The microporous corundum material was prepared using alumina micro-powder as the main raw material, alumina sol and starch as binders by a wet process, achieving the bulk density of 3.05 g · cm^-3, the apparent porosity of 9. 1%, the closed porosity of 12.3%, the median pore diameter of 0. 43 μm, and the thermal conductivity of 6. 5 W· m^-1· K^-1 at 800 ℃ which is 41.6% lower than that of common corundum. The slag resistance of the microporous corundum material was studied by immersion and compared with that of the common corundum aggregate, and the slag resistant mechanism of microporous corundum material was revealed. The results show that the slag resistance of the microporous corundum material is superior to that of the common corundum aggregate, the SEM and EDX show that on the reaction interface between microporous corundum and molten, slag, a continuous isolation layer with a large quantity of CA2 and CA6 columnar crystals is formed; while the common corundum aggregate reacts with the molten slag interface to form a discontinuous isolation layer of columnar crystals, through which a lot of molten slag corrodes or permeates into the aggregate. The mechanism is mainly that the microporous structure is more advantageous to nucleation and growth of CA2 and CA6 columnar crystals; in the reaction with the aggregate, the molten slag gets saturated and the critical solution thickness of the microporous corundum and the common corundum is 0. 16 μm and 0. 34 μm, respectively, this is caused by the smaller microporous corundum aggregate pores; and the smaller pores also increase the second phase ripening rate of microporous corundum, which is 9. 7 times of that of the common corundum.

关键词： low thermal conductivity microporous corundum preparation performance slag resistant mechanism

low-thermal-conductivity thermal barrier coatings with a multi-scale pore design and sintering resistance following thermal exposure

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Rare Metals 2020年第4期39卷 352-367页

作者： Wei-Wei Zhang Zhi-Yuan Wei Li-Yuan Zhang Ya-Zhe Xing Qiang Zhang School of Materials Science and Engineering Chang'an UniversityXi'an 710064China State Key Laboratory for Mechanical Behavior of Materials School of Materials Science and EngineeringXi’an Jiaotong UniversityXi'an 710049China College of Chemistry and Chemical Engineering Neijiang Normal UniversityNeijiang 641112China AECC Beijing Institute of Aeronautical Material Beijing 100095China

High-insulation,long-life thermal barrier coatings(TBCs)decrease the service temperature of superalloys and improve the service life of gas *** in the thermal insulation properties of the coating mainly depends on the optimization of the TBC *** important challenge for TBCs is maintaining a high performance during thermal exposure without degradation,as the pore-rich structure of the topcoat would inevitably be transformed by sintering.A low-thermalconductivity anti-sintering coating can overcome the tradeoff between thermal insulation and sinter *** this review,the design,preparation,and serviceability evaluation of a low-thermal-conductivity anti-sintering coating will be ***,directions for potential development are *** paper provides a comprehensive understanding of the structured tailoring of TBCs for better thermal insulation and anti-sintering performance.

关键词： thermal barrier coatings Multi-scale pore Sintering resistance low thermal conductivity

High entropy ultra-high temperature ceramic thermal insulator(Zr_(1/5)Hf_(1/5)Nb_(1/5)Ta_(1/5)Ti_(1/5))C with controlled microstructure and outstanding properties

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Journal of Materials Science & Technology 2022年第24期119卷 190-199页

作者： Zhuojie Shao Zhen Wu Luchao Sun Xianpeng Liang Zhaoping Luo Haikun Chen Junning Li Jingyang Wang Shenyang National Laboratory for Materials Science Institute of Metal ResearchChinese Academy of SciencesShenyang 110016China School of Materials Science and Engineering University of Science and Technology of ChinaHefei 230026China Science and Technology on Advanced Functional Composites Laboratory Aerospace Research Institute of Materials and Processing TechnologyBeijing 100076China

Due to advancements of hypersonic vehicles,ultra-high temperature thermal insulation materials are urgently requested to shield harsh environment with superhigh heat *** this target,ultra-high temperature ceramics(UHTCs)are the only choice due to their excellent capability at ultra-high *** herein report a novel highly porous high entropy(Zr_(1/5)Hf_(1/5)Nb_(1/5)Ta_(1/5)Ti_(1/5))C fabricated by foam-gelcasting-freeze drying technology combined with in-situ pressureless reaction *** porous(Zr_(1/5)Hf_(1/5)Nb_(1/5)Ta_(1/5)Ti_(1/5))C exhibited ultra-high porosity of 86.4%-95.9%,as well as high strength and low thermal conductivity of 0.70–11.77 MPa and 0.164–0.239 W/(m·K),***,Si C sintering additive only locates at the pit of the surface of sintering neck between UHTC grains,and there is no secondary phase or intergranular film at the grain ***,the oxidation resistance of high entropy carbide powders is greatly improved compared with that of the mixed five carbide *** work clearly highlights the merits of highly porous high entropy(Zr_(1/5)Hf_(1/5)Nb_(1/5)Ta_(1/5)Ti_(1/5))C as an ultra-high temperature thermal insulation material.

关键词： High entropy UHTCs High porosity High strength low thermal conductivity Oxidation resistance

Preparation and properties of CMAS resistant bixbyite structured high-entropy oxides RE_(2)O_(3)(RE=Sm,Eu,Er,Lu,Y,and Yb):Promising environmental barrier coating materials for Al_(2)O_(3)f/Al_(2)O_(3) composites

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Journal of Advanced Ceramics 2021年第3期10卷 596-613页

作者： Yanan SUN Huimin XIANG Fu-Zhi DAI Xiaohui WANG Yan XING Xiaojun ZHAO Yanchun ZHOU School of Materials Science and Engineering Central South UniversityChangsha 410083China Science and Technology on Advanced Functional Composite Laboratory Aerospace Research Institute of Materials&Processing TechnologyBeijing 100076China Shenyang National Laboratory for Materials Science Institute of Metal ResearchChinese Academy of SciencesShenyang 110016China New Energy Technology Engineering Laboratory of Jiangsu Province Nanjing University of Posts and TelecommunicationsNanjing 210023China

Y_(2)O_(3) is regarded as one of the potential environmental barrier coating(EBC)materials for Al_(2)O_(3)f/Al_(2)O_(3)ceramic matrix composites owing to its high melting point and close thermal expansion coefficient to Al_(2)O_(3).However,the relatively high thermal conductivity and unsatisfactory calcium-magnesium-aluminosilicate(CMAS)resistance are the main obstacles for the practical application of Y_(2)O_(3).In order to reduce the thermal conductivity and increase the CMAS resistance,four cubic bixbyite structured high-entropy oxides RE_(2)O_(3),including(Eu_(0.2)Er_(0.2)Lu_(0.2)Y_(0.2)Yb_(0.2))2O_(3),(Sm_(0.2)Er_(0.2)Lu_(0.2)Y_(0.2)Yb_(0.2))2O_(3),(Sm_(0.2)Eu_(0.2)Er_(0.2)Y_(0.2)Yb_(0.2))2O_(3),and(Sm_(0.2)Eu_(0.2)Lu_(0.2)Y_(0.2)Yb_(0.2))2O_(3)were designed and synthesized,among which(Eu_(0.2)Er_(0.2)Lu_(0.2)Y_(0.2)Yb_(0.2))2O_(3)and(Sm_(0.2)Er_(0.2)Lu_(0.2)Y_(0.2)Yb_(0.2))2O_(3)bulks were prepared by spark plasma sintering(SPS)to investigate their mechanical and thermal properties as well as CMAS *** mechanical properties of(Eu_(0.2)Er_(0.2)Lu_(0.2)Y_(0.2)Yb_(0.2))2O_(3)and(Sm_(0.2)Er_(0.2)Lu_(0.2)Y_(0.2)Yb_(0.2))2O_(3) are close to those of Y_(2)O_(3) but become more brittle than Y_(2)O_(3).The thermal conductivities of(Eu_(0.2)Er_(0.2)Lu_(0.2)Y_(0.2)Yb_(0.2))2O_(3) and(Sm_(0.2)Er_(0.2)Lu_(0.2)Y_(0.2)Yb02)2O_(3)(5.1 and 4.6 W·m^(-1)·K^(-1))are only 23.8%and 21.5%respectively of that of Y_(2)O_(3)(21.4 W·m^(-1)·K^(-1)),while their thermal expansion coefficients are close to those of Y_(2)O_(3) and A12O_(3).Most importantly,HE RE_(2)O_(3) ceramics exhibit good CMAS *** being attacked by CMAS at 1350℃for 4 h,the HE RE_(2)O_(3) ceramics maintain their original morphologies without forming pores or cracks,making them promising as EBC materials for Al_(2)O_(3)f/Al_(2)O_(3) composites.

关键词： high-entropy ceramics rare earth oxides low thermal conductivity thermal expansion coefficient CMAS resistance

High-entropy(Y0.2Nd0.2Sm0.2Eu0.2Er0.2)AlO3:A promising thermal/environmental barrier material for oxide/oxide composites

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Journal of Materials Science & Technology 2020年第12期47卷 45-51页

作者： Zifan Zhao Heng Chen Huimin Xiang Fu-Zhi Dai Xiaohui Wang Wei Xu Kuang Sun Zhijian Peng Yanchun Zhou Science and Technology on Advanced Functional Composite Laboratory Aerospace Research Institute of Materials&Processing TechnologyBeijing100076China School of Engineering and Technology China University of GeosciencesBeijing 100083China Shenyang National Laboratory for Materials Science Institute of Metal ResearchChinese Academy of SciencesShenyang110016China Shanghai Chenhua Science and Technology Corporation Limted Shanghai201804China

Yttrium aluminum perovskite(YAl O3)is a promising candidate material for environmental barrier coatings(EBCs)to protect Al2 O3 f/Al2 O3 ceramic matrix composites(CMCs)from the corrosion of high-temperature water vapor in combustion ***,the relatively high thermal conductivity is a notable drawback of YAl O3 for environmental barrier coating ***,in order to make REAl O3 more thermal insulating,a novel high-entropy rare-earth aluminate ceramic(Y0.2Nd0.2Sm0.2Eu0.2Er0.2)AlO3 was designed and *** as-prepared(Y0.2Nd0.2Sm0.2Eu0.2Er0.2)AlO3 ceramic possesses close thermal expansion coefficient(9.02×10-6/oC measured from room temperature to 1200℃)to that of Al2 *** thermal conductivity of(Y0.2Nd0.2Sm0.2Eu0.2Er0.2)AlO3 at room temperature is 4.1 W·m-1K-1,which is almost one third of the value of YAl ***,to effectively prevent the penetration of water vapor from possible pores/cracks of coating layer,which are often observed in T/EBCs,a tri-layer EBC system REAl O3/RE3 Al5 O12/(Al2 O3 f/Al2 O3 CMCs)is *** thermal expansion coefficient to Al2 O3 and low thermal conductivity of(Y0.2Nd0.2Sm0.2Eu0.2Er0.2)AlO3,as well as the formation of dense garnet layer at(Y0.2Nd0.2Sm0.2Eu0.2Er0.2)AlO3/Al2 O3 interface,indicate that this new type of high-entropy ceramic is suitable as a candidate environmental barrier coating material for Al2 O3 f/Al2 O3 CMCs.

关键词： High-entropy ceramics (Y0.2Nd0.2Sm0.2Eu0.2Er0.2AlO3 Tri-layer EBC system low thermal conductivity Al2O3f/Al2O3 CMCs

A simple Pb-doping to achieve bonding evolution, VSn and resonant level shifting for regulating thermoelectric transport behavior of SnTe

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Journal of Materials Science & Technology 2023年第20期151卷 66-72页

作者： Xu-Ye Xin Jun Ma Hong-Quan Liu Yi-Jie Gu Yan-Fang Wang Hong-Zhi Cui College of Materials Science and Engineering Shandong University of Science and TechnologyQingdao 266590China School of Mechanical-electronic and Vehicle Engineering Weifang UniversityWeifang 261061China School of Materials Science and Engineering China University of Petroleum HuadongQingdao 266580China

The intensification of energy crises and environmental pollution inspire researchers’attention to environment-friendly SnTe thermoelectric *** this work,we achieved a lower lattice thermal conductivity and optimized the power factor via the synergistic optimization of bonding characteristic,VSn,and resonant level for the SnTe system,***-introduction produces weak bonding strength,mass fluctuation,and stress distortion,which result in lower thermal *** lowest lattice thermal conductivity achieves 0.66 W m^(–1) K^(–1) at 773 *** introduced VSn relieves loss of electrical conductivity caused by Pb-introduction,and it also makes the bigger g(E)and up-shift of resonance *** VSn,enhanced g(E),and resonant level make electrical conductivity and Seebeck coefficient enhance ***,the further optimization of thermal and electronic transport performance contributes to a higher ZT value of∼0.86 at 773 K in the Sn_(0.685)Pb_(0.285)In_(0.015)Te_(0.7)Se_(0.3) *** strategy of bonding characteristic,VSn,and resonant level synergistic engineering will be widely applicable to various TE systems for achieving better thermoelectric performance.

关键词： SnTe-based material low thermal conductivity Projected crystal orbital hamiltonian populations VSn Resonant level

An Effective Green Porous Structural Adhesive for thermal Insulating,Flame-Retardant,and Smoke-Suppressant Expandable Polystyrene Foam

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Engineering 2022年第10期17卷 151-160页

作者： Meng-En Li Hai-Bo Zhao Jin-Bo Cheng Ting Wang Teng Fu Ai-Ning Zhang Yu-Zhong Wang The Collaborative Innovation Center for Eco-Friendly and Fire-Safety Polymeric Materials(MoE)&State Key Laboratory of Polymer Materials Engineering&National Engineering Laboratory of Eco-Friendly Polymeric Materials(Sichuan) College of ChemistrySichuan UniversityChengdu 610064China

To develop an efficient way to overcome the contradiction among flame retardancy,smoke suppression,and thermal insulation in expanded polystyrene(EPS)foams,which are widely used insulation materials in buildings,a novel"green"porous bio-based flame-retard ant starch(FRS)coating was designed from starch modified with phytic acid(PA)that simultaneously acts as both a flame retardant and an *** porous FRS coating has open pores,which,in combination with the closed cells formed by EPS beads,create a hierarchically porous structure in FRS-EPS that results in superior thermal insulation with a lower thermal conductivity of 27.0 mW·(m·K)^(-1).The resultant FRS-EPS foam showed extremely low heat-release rates and smoke-production release,indicating excellent fire retardancy and smoke *** specific optical density was as low as 121,which was 80.6%lower than that of neat EPS,at *** FRS-EPS also exhibited self-extinguishing behavior in vertical burning tests and had a high limiting oxygen index(LOI)value of 35.5%.More interestingly,after being burnt with an alcohol lamp for 30 min,the top side temperature of the FRS-EPS remained at only 140℃with ignition,thereby exhibiting excellent fire *** analysis confirmed the intumescent action of FRS,which forms a compact phosphorus-rich hybrid barrier,and the phosphorus-containing compounds that formed in the gas phase contributed to the excellent flame retardancy and smoke suppression of *** novel porous biomass-based FRS system provides a promising strategy for fabricating polymer foams with excellent flame retardancy,smoke suppression,and thermal insulation.

关键词： Biomass porous coating Expanded polystyrene foam low thermal conductivity Flame retardancy Smoke suppression