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Excellent energy storage properties in non-stoichiometric Bi_(0.5)Na_(0.5)TiO_(3)-based relaxor ferroelectric ceramics

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Chinese Chemical Letters 2024年第7期35卷 470-472页

作者： Shunshun Jiang Ji zhang jing Wang Shan-tao zhang School of materials science and engineering Nanjing University of Science&TechnologyNanjing 210094China State key laboratory of Mechanics and Control of Mechanical Structures College of Aerospace EngineeringNanjing University of Aeronautics and AstronauticsNanjing 210016China National laboratory of Solid State Microstructures Department of Materials Science and EngineeringCollege of Engineering and Applied Science&Jiangsu Key Laboratory of Artificial Functional Materials&Collaborative Innovation Center of Advanced MicrostructuresNanjing UniversityNanjing 210093China

The rapid development of high-power and pulsed-power techniques inspires extensive investigates on high-performance ceramic-based ***,the low recoverable energy density(Wrec)hampers their wider ***,the non-stoichiometric Bi_(0.5)Na_(0.5)TiO_(3)-based ceramics were designed and *** proper introduction of oxygen vacancies facilitated activating defect dipole,giving rise to reduced remanent ***,the optimal composition exhibited an exceptional high Wrec of 8.3 J/cm^(3),a high efficiency of 85%,and excellent anti-fatigue and thermal *** work provides an efficient approach to explore ceramic capacitors with high capacitive energy storage performances.

关键词： Non-stoichiometric Bi_(0.5)Na_(0.5)TiO_(3) Ceramic capacitor Energy density Thermal stability

Correlation between supercooled liquid region and crystallization behavior with alloy composition of La-Al-Cu metallic glasses

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science china(Physics,Mechanics & Astronomy) 2011年第9期54卷 1608-1611页

作者： zhang QingChao pang shujie LI Yi zhang tao key laboratory of aerospace materials and performance (Ministry of Education) School of Materials Science and Engineering Beijing University of Aeronautics and Astronautics Beijing 100191 China department of materials science and engineering National University of Singapore Singapore 117576 Singapore

Bulk metallic glasses (BMGs) with large supercooled liquid region are promising materials for superplastic forming. In this paper, we demonstrate a microstructure-based strategy to pinpoint the composition with the largest supercooled liquid region in La 86 x Al 14 Cu x (x=16 at%-20 at%) metallic glass system. By monitoring the changes in crystallization behavior of the glassy alloys with composition to search for the alloys exhibiting eutectic crystallization, the glassy alloys with the largest supercooled liquid region in the given alloy system can be found. The metallic glasses with Cu contents of 16 at%-19 at% exhibited two crystallization peaks, and the primary crystallization product was identified to be α-La by means of DSC, XRD and TEM. The increase in Cu content resulted in the decay of the primary crystallization peak and the increase in onset temperature of crystallization, leading to the enlargement of supercooled liquid region. By further suppressing the α-La primary crystallization with increasing Cu content up to 20 at%, the eutectic crystallization of α-La and LaCu 13 through one crystallization reaction occurred upon heating, where the largest supercooled liquid region of 65 K for La 66 Al 14 Cu 20 glassy alloy was located. This study indicats that, in a given glassy alloy system, a larger supercooled liquid region can be achieved by optimizing the alloy compositions to suppress the primary crystallization.

关键词： bulk metallic glass supercooled liquid region crystallization

A Ti–Zr–Cu–Ni–Co–Fe–Al–Sn amorphous filler metal for improving the strength of Ti–6Al–4V alloy brazing joint

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Progress in Natural science:materials International 2017年第6期27卷 687-694页

作者： Lulu Sun shujie pang Ying Liu Huaping Xiong tao zhang key laboratory of aerospace materials and performance (Ministry of Education) School of Materials Science and Engineering Beihang University Welding and Plastic Forming Division Beijing Institute of Aeronautical Materials

Ti;Zr;Cu;Ni;Co;Fe;Al;Sn;（at%） amorphous filler metal with low Cu and Ni contents in a melt-spun ribbon form was developed for improving mechanical properties of Ti–6Al–4V alloy brazing joint through decreasing brittle intermetallics in the braze zone. Investigation on the crystallization behavior of the multicomponent Ti–Zr–Cu–Ni–Co–Fe–Al–Sn amorphous alloy indicates the high stability of the supercooled liquid against crystallization that favors the formation of amorphous structure. The Ti–6Al–4V joint brazed with this Ti-based amorphous filler metal with low total content of Cu and Ni at 1203K for 900s mainly consists of α-Ti, β-Ti,minor Ti–Zr-rich phase and only a small amount of Ti;Cu intermetallics, leading to the high shear strength of the joint of about 460 MPa. Multicomponent composition design of amorphous alloys is an effective way of tailoring filler metals for improving the joint strength.

关键词： Amorphous alloy Brazing Titanium alloy Microstructure Mechanical properties

Formation and biocorrosion behavior of Zr-Al-Co-Nb bulk metallic glasses

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Chinese science Bulletin 2012年第14期57卷 1723-1727页

作者： LU XuYang HUANG Lu pang shujie zhang tao key laboratory of aerospace materials and performance （Ministry of Education） School of Materials Science and Engineering BeihangUniversity Beijing 100191 China

Ni-and Cu-free Zr-Al-Co-Nb glassy alloys with different Nb and Co contents were synthesized by melt spinning and copper mold *** effects of Nb addition to partially replace Co in the Zr55Al20Co25 glassy alloy on the glass-forming ability,thermal properties,in-vitro biocorrosion behavior and surface wettability of the metallic glasses were *** addition of Nb up to 5 at.% slightly decreased the supercooled liquid region and the glass-forming ability(GFA),the alloys could be casted in a bulk glassy rod form with diameters up to *** Zr-Al-Co-Nb glassy alloys were spontaneously passivated with low passive current densities in phosphate buffered saline and Hanks' *** of "toxic" Co by Nb is effective in improved the corrosion resistance of the Zr-Al-Co glassy *** contact angle measurements showed that Nb addition increased the hydrophilicity of the glassy alloys,which may enhance cell adhesion of the alloys in biomedical applications.

关键词：大块金属玻璃腐蚀行为生物玻璃形成能力铌非晶合金锆铝

High-zirconium bulk metallic glasses with high strength and large ductility

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science china(Physics,Mechanics & Astronomy) 2013年第3期Mechanics & Astronomy) .卷 540-544页

作者： YANG YaoWei HUA NengBin LI Ran pang shujie zhang tao key laboratory of aerospace materials and performance(Ministry of Education) School of Materials Science and EngineeringBeihang University

In this paper,high-zirconium Zr66+2xAl9-x(Ni1/3Cu2/3) 25-x(x=0,1,2 at.%) bulk metallic glasses with high strength and large ductility were fabricated by copper mould *** effects of zirconium content on the glass-forming ability(GFA),thermal properties and mechanical properties were investigated using X-ray diffractometer(XRD),differential scanning calorimeter(DSC),and mechanical testing system in compressive and three-point bending modes,*** high-zirconium BMGs show the critical diameters of 3-5 mm,the supercooled liquid region ranging from 70 K to 99 K,and the yield strength of over 1700 *** Zr 70 Al 7(Ni1/3Cu2/3) 23 BMG exhibits a large compressive plastic strain up to 21% and a high notch toughness value of 60.6 MPa m 1/*** increase in Zr content results in the decrease in GFA and thermostability,and in the improvement of plasticity under compressive and three-point bending *** superior plasticity of high-zirconium BMGs is attributed to their high Poisson's ratio and small elastic modulus ratio /B.

关键词： bulk metallic glass zirconium alloy mechanical property elastic modulus

Ti-Cu-Zr-Fe-Nb ultrafine structure-dendrite composites with good mechanical properties and biocompatibility

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Progress in Natural science:materials International 2013年第6期23卷 557-561页

作者： Guan Wang shujie pang Haifei Li Min zhang Gang Zhou tao zhang key laboratory of aerospace materials and performance(Ministry of Education) School of Materials Science and EngineeringBeihang University School of Biological science and Mechanical engineering Beihang University

Ti-Cu-Zr-Fe-Nb ultrafine structure-dendrite composites were designed by inducing Nb and more Ti to a Ti-Cu-Zr-Fe glass-forming alloy composition and prepared by copper mold *** composite alloys consist of β-Ti dendrites and ultrafine-structured CuTiand CuTi phases as well as a trace amount of glassy *** volume fraction of β-Ti dendrites increases with the increase in content of Nb which acted as the β-Ti phase stabilizer in the *** composites exhibit high compressive yield strength exceeding1200 MPa,maximum strength around 1800 MPa and low Young’s modulus around 48 *** plasticity of the alloys is strongly influenced by the volume fraction and morphology of the dendritic β-Ti phase,and the compressive plastic strain was enlarged from 5.9%for the 4 at%Nb alloy to 9.2%for the 8 at%Nb *** preliminary cell culture experiment indicated good biocompatibility of the composite alloys free from highly toxic elements Ni and *** Ti-based composite alloys are promising to have potential structural and biomedical applications due to the combination of good mechanical properties and biocompatibility.

关键词： Ti-based alloy Composite Dendrite Mechanical property Biocompatibility

Effect of Ni addition on the glass-forming ability and soft-magnetic properties of FeNiBPNb metallic glasses

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Chinese science Bulletin 2011年第36期56卷 3932-3936页

作者： WANG AnDing zhang MingXiao zhang JianHua MEN He SHEN BaoLong pang shujie zhang tao Zhejiang Province key laboratory of Magnetic materials and Application Technology Key Laboratory of Magnetic Materials and Devices Ningbo Institute of Materials Technology ＆ Engineering Chinese Academy of Sciences Ningbo 315201 China School of materials science and engineering Beijing University of Aeronautics and Astronautics Beijing 100083 China

The effect of Ni addition on the glass-forming ability (GFA) and soft-magnetic properties of an (Fe1-xNix)75.5B14.5P7Nb3 (x=0-0.6) alloy system were investigated. We found that the addition of Ni was effective in allowing the alloy to approach a eutectic point as well as increasing the thermal stability of the supercooled liquid. By increasing the amount of Ni,the supercooled liquid region (ΔTx),the reduced glass transition temperature Trg (Tg/Tl) and the Y parameter [Tx/(Tg+Tl)] increased from 49 to 75 K,0.540 to 0.594 and 0.373 to 0.405,respectively. As a result,novel (Fe1-xNix)75.5B14.5P7Nb3 bulk metallic glass (BMG) rods with a maximum diameter of 1 mm were synthesized with a composition of x=0.5 and x=0.6 by copper mold casting. These metallic glasses have a moderate saturation magnetization of 0.37-1.20 T with good soft-magnetic properties,i.e. a low coercivity of 1.4-3.3 A/m and a high effective permeability of 13100-20900 at 1 kHz. The simultaneous achievement of a high GFA and good soft-magnetic properties for the FeNi-based alloy system is promising for the future development of BMGs.

关键词：大块金属玻璃玻璃形成能力软磁性能玻璃化转变温度合金系统饱和磁化强度过冷液相区有效渗透率

Distinct microstructure and property evolution of 0.76(Bi_(0.5)Na_(0.5))TiO_(3)-0.24SrTiO_(3) ferroelectric ceramics synthesized with different TiO_(2) reactants

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Journal of materials science & Technology 2023年第20期151卷 73-79页

作者： Jian Guo Ji zhang jing Wang Shan-tao zhang National laboratory of Solid State Microstructures College of Engineering and Applied Sciences&Jiangsu Key Laboratory of Artificial Functional Materials&Collaborative Innovation Center of Advanced MicrostructuresNanjing UniversityNanjing 210093China School of materials science and engineering Nanjing University of Science&TechnologyNanjing 210094China State key laboratory of Mechanics and Control of Mechanical Structures College of Aerospace EngineeringNanjing University of Aeronautics and AstronauticsNanjing 210016China

Single phase 0.76(Bi_(0.5)Na_(0.5))TiO_(3)–0.24SrTiO_(3) ferroelectric ceramics have been synthesized with homogenous anatase and hierarchical rutile TiO_(2) raw reactants(BNST-A and BNST-R).Either calcined powder persists the microstructure characteristics of raw *** the result,when the sintering temperature increases from 1000 to 1200℃,the average grain size and density of BNST-A increase from 0.49 to 1.48μm and 5.02 to 5.61 g/cm^(3),while those of BNST-R from 0.86 to 1.44μm and 5.37 to 5.61 g/cm^(3).BNST-A illustrates a predominant ergodic relaxor state,and BNST-R prefers a non-ergodic relaxor state,as evidenced by the distinct polarization-electric field loops and current-electric field ***,such a distinct ferroelectric state is independent of sintering *** is believed that the special hierarchical microstructure of rutile TiO_(2) reactant is beneficial to form denser ceramics with larger grains,and thus suppresses the contributions of polar nanoregions and defect-induced built-in field to ferroelectric property,leading to non-ergodic relaxor *** work clearly demonstrates the nonnegligible effects of TiO_(2) reactants on the microstructure and properties of BNST ferroelectric ceramics.

关键词： BNST ferroelectric ceramics TiO_(2)raw reactants Microstructure and property evolution

2D-SiC/SiC复合材料的弹丸冲击损伤及冲击后拉伸性能

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无机材料学报 2024年第5期39卷 494-500页

作者：李广宇岳一凡王波张程煜索涛李玉龙西北工业大学航空学院西安710072 陕西省冲击动力学及工程应用重点实验室西安710072 强度与结构完整性全国重点实验室西安710065 西北工业大学材料学院西安710072 西北工业大学民航学院西安710072

连续纤维增韧陶瓷基复合材料以其良好的高温性能而被广泛应用在航空发动机等高温部件处,但服役过程中容易受到异物碎片冲击,这受到了广泛关注。研究采用轻气炮对化学气相渗透(CVI)技术制备的2D-SiC/SiC试样进行弹丸冲击,利用高速摄像机... 详细信息

连续纤维增韧陶瓷基复合材料以其良好的高温性能而被广泛应用在航空发动机等高温部件处,但服役过程中容易受到异物碎片冲击,这受到了广泛关注。研究采用轻气炮对化学气相渗透(CVI)技术制备的2D-SiC/SiC试样进行弹丸冲击,利用高速摄像机记录冲击过程,使用光学显微镜和CT观察异物损伤(FOD)的表面和内部结构,探讨了2D-SiC/SiC复合材料的高速冲击损伤特性。结果表明,2D-SiC/SiC复合材料的高速冲击损伤形式包括锥形裂纹、层间分层、纤维断裂以及基体压溃等。通过表征损伤发现,试件背部损伤和边缘处分层损伤由反射拉伸波造成,随着冲击速度提升,弹丸与拉伸波共同作用会造成试件穿透,试件边缘分层损伤减弱。对高速冲击后的试件进行准静态拉伸试验,明确了剩余力学性能与冲击速度、弹丸直径的关系,表明剩余拉伸强度是表征冲击损伤程度的有效参数。同时,采用数字图像相关(DIC)方法获得拉伸过程中的应变分布,并结合不同弹丸直径、冲击速度冲击后的剩余拉伸强度,进一步对比探究不同变量对冲击损伤的影响。研究结果表明弹丸直径是高速冲击损伤程度的主要影响因素。

关键词：陶瓷基复合材料高速冲击异物损伤剩余拉伸强度数字图像相关技术