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Zr_(2)SeB and Hf_(2)SeB:Two new MAB phase compounds with the Cr_(2)AlC-type MAX phase(211 phase)crystal structures

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Journal of Advanced Ceramics 2022年第11期11卷 1764-1776页

作者： Qiqiang ZHANG Yanchun ZHOU Xingyuan SAN Wenbo LI Yiwang BAO Qingguo FENG salvatore grasso Chunfeng HU Key Laboratory of Advanced Technologies of Materials Ministry of EducationSchool of Materials Science and EngineeringSouthwest Jiaotong UniversityChengdu 610031China Science and Technology on Advanced Functional Composite Laboratory Aerospace Research Institute of Materials&Processing TechnologyBeijing 100076China Hebei Key Lab of Optic–Electronic Information and Materials College of Physics Science and TechnologyHebei UniversityBaoding 071002China State Key Laboratory of Green Building Materials China Building Materials AcademyBeijing 100024China

The ternary or quaternary layered compounds called MAB phases are frequently mentioned recently together with the well-known MAX ***,MAB phases are generally referred to layered transition metal borides,while MAX phases are layered transition metal carbides and nitrides with different types of crystal structure although they share the common nano-laminated structure *** order to prove that MAB phases can share the same type of crystal structure with MAX phases and extend the composition window of MAX phases from carbides and nitrides to borides,two new MAB phase compounds Zr_(2)SeB and Hf_(2)SeB with the Cr_(2)AlC-type MAX phase(211 phase)crystal structure were discovered by a combination of first-principles calculations and experimental verification in this ***-principles calculations predicted the stability and lattice parameters of the two new MAB phase compounds Zr_(2)SeB and Hf_(2)*** they were successfully synthesized by using a thermal explosion method in a spark plasma sintering(SPS)*** crystal structures of Zr_(2)SeB and Hf_(2)SeB were determined by a combination of the X-ray diffraction(XRD),scanning electron microscopy(SEM),and high-resolution transmission electron microscopy(HRTEM).The lattice parameters of Zr_(2)SeB and Hf_(2)SeB are a=3.64398Å,c=12.63223Åand a=3.52280Å,c=12.47804Å,*** the atomic positions are M at 4f(1/3,2/3,0.60288[Zr]or 0.59889[Hf]),Se at 2c(1/3,2/3,1/4),and B at 2a(0,0,0).And the atomic stacking sequences follow those of the Cr_(2)AlC-type MAX *** work opens up the composition window for the MAB phases and MAX phases and will trigger the interests of material scientists and physicists to explore new compounds and properties in this new family of materials.

关键词： Zr_(2)SeB and Hf_(2)SeB MAB phase MAX phase first-principles calculations thermal explosion synthesis

A review of electromagnetic processing of materials(EPM):Heating,sintering,joining and forming

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Journal of Materials Science & Technology 2021年第10期69卷 239-272页

作者： Mattia Biesuz Theo Saunders Daoyao Ke Michael J.Reece Chungfeng Hu salvatore grasso Southwest Jiaotong University School of Materials Science and EngineeringChengdu 611756China Queen Mary University of London Mile End Road.El 4NS LondonUK University of Trento Department of Industrial EngineeringVia Sommarive 938123 TrentoItaly

Electricity is an efficient form of energy,and the growing interest in electricity-assisted manufacturing is motivated by its inherent energy saving and reduced environmental *** this,Electromagnetic Processing of Materials(EPM)allows the fabrication of materials with new compositions,metastable phases and nanograined microstructures that cannot be obtained using conventional heating processes using *** review covers EPM for the manufacture of ceramic and metal bulk components,with a specific focus on the effects of electric fields and electromagnetic radiations on processing in a wide spectrum of frequencies ranging from DC(f=0 Hz)to visible light(f=10^(14)–10^(15)Hz).The manuscript is divided into two *** first part provides a comprehensive overview of the interactions between matter and electric field/current,including heating phenomena(resistive Joule,induction,dielectric heating,electric arcs)and athermal effects(electromigration,electroplasticity,electrochemical reactions,ponderomotive force and others).The second part is focused on the technological application of the techniques,covering heat treatments,joining,sintering and *** distinct physical phenomena are involved in EPM:resistive Joule and induction heating,electrochemical reactions,electroplasticity,electric arcs and electromagnetic heating based on radio and microwave frequencies(mainly used for heating dielectric materials;i.e.,dielectric heating)or on the IR/visible light(IR heating and lasers).

关键词： Field-assisted sintering Electroplasticity Joining Welding Induction heating Arc melting

Synthesis,microstructure,and properties of high purity Mo_(2)TiAlC_(2) ceramics fabricated by spark plasma sintering

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Journal of Advanced Ceramics 2020年第6期9卷 759-768页

作者： Yunhui NIU Shuai FU Kuibao ZHANG Bo DAI Haibin ZHANG salvatore grasso Chunfeng HU State Key Laboratory of Environment-Friendly Energy Materials Southwest University of Science and TechnologyMianyang 621010China Key Laboratory of Advanced Technologies of Materials Ministry of EducationSchool of Materials Science and EngineeringSouthwest Jiaotong UniversityChengdu 610031China Institute of Nuclear Physics and Chemistry China Academy of Engineering PhysicsMianyang 621900China

The synthesis,microstructure,and properties of high purity dense bulk Mo_(2)TiAlC_(2) ceramics were *** purity Mo_(2)TiAlC_(2) powder was synthesized at 1873 K starting from Mo,Ti,Al,and graphite powders with a molar ratio of 2:1:1.25:*** synthesis mechanism of Mo_(2)TiAlC_(2) was explored by analyzing the compositions of samples sintered at different *** was found that the Mo_(2)TiAlC_(2) phase was formed from the reaction among Mo3Al2C,Mo2C,TiC,and *** Mo_(2)TiAlC_(2) bulk sample was prepared by spark plasma sintering(SPS)at 1673 K under a pressure of 40 *** relative density of the dense sample was 98.3%.The mean grain size was 3.5μm in length and 1.5μm in *** typical layered structure could be clearly *** electrical conductivity of Mo_(2)TiAlC_(2) ceramic measured at the temperature range of 2-300 K decreased from 0.95×10^(6) to 0.77×10^(6)Ω^(-1)·m^(-1).Thermal conductivity measured at the temperature range of 300-1273 K decreased from 8.0 to 6.4 W·(m·K)^(-1).The thermal expansion coefficient(TEC)of Mo_(2)TiAlC_(2) measured at the temperature of 350-1100 K was calculated as 9.0×10^(-6) K^(-1).Additionally,the layered structure and fine grain size benefited for excellent mechanical properties of low intrinsic Vickers hardness of 5.2 GPa,high flexural strength of 407.9 MPa,high fracture toughness of 6.5 MPa·m^(1/2),and high compressive strength of 1079 *** at the indentation load of 300 N,the residual flexural strength could hold 84% of the value of undamaged one,indicating remarkable damage ***,it was confirmed that Mo_(2)TiAlC_(2) ceramic had a good oxidation resistance below 1200 K in the air.

关键词： MAX phase Mo_(2)TiAlC_(2) synthesis microstructure properties

Spark plasma sintering of damage tolerant and machinable YAM ceramics

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Journal of Advanced Ceramics 2013年第2期2卷 193-200页

作者： Qian WANG salvatore grasso Chunfeng HU Haibin ZHANG Shu CAI Yoshio SAKKA Qing HUANG Ningbo Institute of Materials Technology and Engineering(NIMTE) Chinese Academy of Sciences(CAS)Ningbo 315201China Key Laboratory for Advanced Ceramics and Machining Technology of Ministry of Education Tianjin UniversityTianjin 300072China School of Engineering&Materials Science and Nanoforce Technology Ltd. Queen Mary University of LondonMile End RoadLondon E14NSUK China Academy of Engineering Physics Mianyang 621900China National Institute for Materials Science(NIMS) TsukubaIbaraki 305-0047Japan

Single-phase Y_(4)Al_(2)O_(9)(YAM)powders were synthesized via solid-state reaction starting from nano-sized Al_(2)O_(3) and Y_(2)O_(3).Fully dense(99.5%)bulk YAM ceramics were consolidated by spark plasma sintering(SPS)at 1800℃.We demonstrated the excellent damage tolerance and good machinability of YAM *** properties are attributed to the easy slipping along the weakly bonded crystallographic planes,resulting in multiple energy dissipation mechanisms such as transgranular fracture,shear slipping and localized grain crushing.

关键词： ceramic synthesis microstructure property damage tolerance

Theoretical prediction,synthesis,and crystal structure determination of new MAX phase compound V2SnC

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Journal of Advanced Ceramics 2020年第4期9卷 481-492页

作者： Qiang Xu Yanchun Zhou Haiming Zhang Anna Jiang Quanzheng Tao Jun Lu Johanna Rosén Yunhui Niu salvatore grasso Chunfeng Hu Key Laboratory of Advanced Technologies of Materials Ministry of EducationSchool of Materials Science and EngineeringSouthwest Jiaotong UniversityChengdu610031China Science and Technology on Advanced Functional Composite Laboratory Aerospace Research Institute of Materials&Processing TechnologyBeijing100076China School of Mechanical Electronic and Control EngineeringBeijing Jiaotong UniversityBeijing100044China Thin Film Physics Division Department of PhysicsChemistryand Biology(IFM)Linköping UniversityLinköpingSE-58183Sweden State Key Laboratory of Environment-friendly Energy Materials Southwest University of Science and TechnologyMianyang621010China

Guided by the theoretical prediction,a new MAX phase V2SnC was synthesized experimentally for the first time by reaction of V,Sn,and C mixtures at 1000°*** chemical composition and crystal structure of this new compound were identified by the cross-check combination of first-principles calculations,X-ray diffraction(XRD),energy dispersive X-ray spectroscopy(EDS),and high resolution scanning transmission electron microscopy(HR-STEM).The stacking sequence of V2C and Sn layers results in a crystal structure of space group P63/*** a-and c-lattice parameters,which were determined by the Rietveld analysis of powder XRD pattern,are 0.2981(0)nm and 1.3470(6)nm,*** atomic positions are V at 4f(1/3,2/3,0.0776(5)),Sn at 2d(2/3,1/3,1/4),and C at 2a(0,0,0).A new set of XRD data of V2SnC was also *** calculations suggest that this new compound is stable with negative formation energy and formation enthalpy,satisfied Born-Huang criteria of mechanical stability,and positive phonon branches over the Brillouin *** also has low shear deformation resistance c44(second-order elastic constant,cij)and shear modulus(G),positive Cauchy pressure,and low Pugh’s ratio(G/B=0.500<0.571),which is regarded as a quasi-ductile MAX *** mechanism underpinning the quasi-ductility is associated with the presence of a metallic bond.

关键词： V2SnC new MAX phase compound crystal structure first-principles calculations

Cold Hydrostatic Sintering:From shaping to 3D printing

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Journal of Materiomics 2019年第3期5卷 496-501页

作者： Anna Jiang Daoyao Ke Ludi Xu Qiang Xu Jiang Li Jiabei Wei Chunfeng Hu salvatore grasso Key Laboratory of Advanced Technologies of Materials Ministry of EducationSchool of Materials Science and EngineeringSouthwest Jiaotong UniversityChengdu610031China Key Laboratory of Transparent Opto-functional Inorganic Materials Shanghai Institute of CeramicsChinese Academy of SciencesShanghai201899China

We developed a novel consolidation technique,Cold Hydrostatic Sintering(CHS),which allows near full densification of *** technique is inspired by biosilicification and geological formation of siliceous *** established cold sintering method which is based on uniaxial pressure,CHS employs an isostatic pressure to enable room temperature consolidation of bulks having a complex threedimensional *** resulting material is transparent(in line transmittance exceeding 70% in the visible range)and *** drying,the Vickers hardness was as high 1.4 GPa which half of materials consolidated at 1200℃ and it is the highest among all materials processed at room *** CHS method,because of its simplicity,might be suitable for broad range of applications including 3D printing,mould forming and preparation of multi-layered *** of the absence of the firing step,CHS could be directly integrated in the manufacturing of a wide range of hybrid(organic/inorganic)materials for functional and biological applications.

关键词： Silica Cold Hydrostatic Sintering(CHS) Shaping 3D printing

Effect of texture microstructure on tribological properties of tailored Ti3AlC2 ceramic

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Journal of Advanced Ceramics 2017年第2期6卷 120-128页

作者： Ludi XU Degui ZHU salvatore grasso Tohru S.SUZUKI Akira KASAHARA Masahiro TOSA Byung-nam KIM Yoshio SAKKA Minhao ZHU Chunfeng HU Key Laboratory of Advanced Technologies of Materials Ministry of Education School of Materials Science and Engineering Southwest Jiaotong University Chengdu 610031 China School of Engineering and Material Science Queen Mary University of London London El 4NS UK National Institute for Materials Science Tsukuba Ibaraki 305-0047 Japan

Tribological property of c-axis textured shell-like Ti3AlC2 ceramic was investigated using reciprocating sliding balls (SUS304) under loads of 1, 5, and 9 N. It was found that the textured top surface (TTS), corresponding to the (000l) plane, shows the lowest mean coefficient of friction in comparison with those measured on the textured side surface (TSS), where the sliding directions are parallel (TSS-1) and perpendicular (TSS-2) to c axis, under the same load. Among all the tested orientations, the TSS-2 exhibited the lowest wear rate of 1.51×10−3 mm3/(N·m) under the load of 9 N. The worn mechanisms on the TTS and TSS-1 were delamination, grain fracture, and grain spalling-off. On the TSS-2, plowing effect against balls was the dominating mechanism. This work suggests the criteria to maximize the wear resistance in the load range of 1–9 N.

关键词： tailored Ti 3 AlC 2 mean coefficient of friction wear rate worn mechanisms

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磁性MAX相陶瓷研究进展

现代技术陶瓷 2020年第4期41卷 217-230页

作者：付帅朱德贵 salvatore grasso 胡春峰西南交通大学材料科学与工程学院

MAX相陶瓷综合了陶瓷材料和金属材料的诸多优点,包括低密度、高模量、良好的导电/导热性能、优异的抗热震性能、抗损伤性能以及优良的抗高温氧化性能等,已经获得研究者的广泛关注。近年来,带有磁性的MAX相陶瓷相继被发现并被成功制备。... 详细信息

MAX相陶瓷综合了陶瓷材料和金属材料的诸多优点,包括低密度、高模量、良好的导电/导热性能、优异的抗热震性能、抗损伤性能以及优良的抗高温氧化性能等,已经获得研究者的广泛关注。近年来,带有磁性的MAX相陶瓷相继被发现并被成功制备。本文结合国内外在该领域的发展现状,重点介绍当前已被发现磁性MAX相陶瓷的合成和磁性特性。

关键词： MAX相合成磁性

Soil Uncertainties on Performance of Geotechnical Works

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Journal of Civil Engineering and Architecture 2010年第5期4卷 37-47页

作者： Michele Maugeri salvatore grasso Department of Civil and Environmental Engineering University of Catania Catania 95125 Italy

Performance-Based Design (PBD) is a more rational approach, particularly in seismic environments. In this approach it is relevant the performance required to structures and to geotechnical works, as well as the geotechnical constitutive models used to predict the performance. The parameters of the constitutive models are related in turn to soil properties. So soil properties are a key point for Performance-Based Design. Questions arising are: (i) which are the more relevant soil properties to solve a specific PBD geotechnical problem? (ii) which are the more relevant model parameters and how they can be evaluated and/or correlated to soil properties? (iii) which is the role of the soil parameters uncertainty in Performance-Based Design? An answer to these questions is given in this paper, outlining the potential offered by the new advanced in-situ and laboratory tests and discussing the performance required by some geotechnical works.

关键词：岩土工程问题工程性能不确定性岩土本构模型基于性能的设计性能化设计土壤性质土壤性状