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Microstructure, Tensile Properties and Work Hardening Behavior of an Extruded Mg–Zn–Ca–Mn Magnesium Alloy

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Acta Metallurgica Sinica(English Letters) 2020年第7期33卷 922-936页

作者： Kai-Bo Nie zhi-hao zhu Paul Munroe Kun-Kun Deng Jun-Gang Han College of Materials Science and Engineering Taiyuan University of TechnologyTaiyuan 030024China School of Materials Science and Engineering UNSW AustraliaKensingtonNSW 2052Australia

A new Mg-2.2 wt% Zn alloy containing 1.8 wt% Ca and 0.5 wt% Mn has been developed and subjected to extrusion under different extrusion *** finest(~0.48 μm) recrystallized grain structures,containing both nano-sized MgZn2 precipitates and α-Mn nanoparticles,were obtained in the alloy extruded at 270℃/0.01 mm *** this alloy,the deformed coarse-grain region possessed a much stronger texture intensity(~32.49 mud) relative to the recrystallized fine-grain region(~13.99 mud).A positive work hardening rate in the third stage of work hardening curve was also evident in the alloy extruded at 270℃,which was related to the sharp basal texture and which provided insufficient active slip *** high work hardening rate in the fourth stage contributed to the high ductility extruded at 270℃/1 mm *** alloy exhibited a weak texture,and the examination of fracture surface revealed highly dimpled *** optimum tensile strength was achieved in the alloy extruded at 270℃/0.01 mm s-1,and the yield strength,ultimate tensile strength and elongation to failure were^364.1 MPa,~394.5 MPa and^7.2%,*** grain strengthening from the recrystallized fine-grain region played the greatest role in the strength increment of this alloy compared with Orowan strengthening and dislocation strengthening in the deformed coarse-grain regions.

关键词： alloy grain strengthening

High-strength Ti-Al-V-Zr cast alloys designed using α and β cluster formulas

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China Foundry 2023年第1期20卷 23-28页

作者： zhi-hao zhu Yu-han Liu zhi-peng Chen Tian-yu Liu Shuang Zhang Dan-dan Dong Chuang Dong Key Laboratory for Materials Modification by Laser Ionand Electron Beams and School of Materials Science and EngineeringDalian University of TechnologyDalian 116024LiaoningChina State Key Laboratory of Light Alloy Casting Technology for High-end Equipment Shenyang Research Institute of Foundry Co.Ltd.Shenyang 110022China School of Materials Science and Engineering Dalian Jiaotong UniversityDalian 116028LiaoningChina College of Physical Science and Technology Dalian UniversityDalian 116622LiaoningChina

Ti-Al-V-Zr quaternary titanium alloys were designed followingα-{[Al-Ti12](AlTi2)}17-n+β-{[Al-Ti12Zr2](V3)}n,where n=1-7(the number ofβunits),on the basis of the dual-cluster formula of popular Ti-6Al-4V *** an alloying strategy aims at strengthening the alloy via Zr and V co-alloying in theβ-Ti unit,based on the originalβformula[Al-Ti14](V2Ti)of Ti-6Al-4V *** microstructures of the as-cast alloys by copper-mold suction-casting change from pureα(n=1)toα+α’martensite(n=7).When n is 6,Ti-5.6Al-6.8V-8.1Zr alloy reaches the highest ultimate tensile strength of 1,293 MPa and yield strength of 1,097 MPa,at the expense of a low elongation of 2%,mainly due to the presence of a large amount of acicularα’*** specific strength far exceeds that of Ti-6Al-4V alloy by 35%.

关键词： titanium alloy cluster-plus-glue-atom model composition design microstructure mechanical properties

Effect of processing parameters on formability, microstructure, and micro-hardness of a novel laser additive manufactured Ti-6.38Al-3.87V-2.43Mo alloy

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China Foundry 2022年第2期19卷 158-168页

作者： Tian-yu Liu zhi-hao zhu Shuang Zhang Xiao-hua Min Chuang Dong School of Materials Science and Engineering Dalian University of TechnologyDalian 116024LiaoningChina School of Materials Science and Engineering Dalian Jiaotong UniversityDalian 116028LiaoningChina

A novel Ti-6.38Al-3.87V-2.43Mo alloy was designed with a cluster formula of 12[Al-Ti12](V0.75Mo0.25Ti2)+4[Al-Ti12](Al3)by replacing Ti with Mo/V on the basis of the Ti-Al congruent *** effects of laser power and scanning speed on the molten pool size,surface roughness,relative density,microstructure,and micro-hardness of single-track and bulk Ti-6.38Al-3.87V-2.43Mo samples prepared via laser additive manufacturing(LAM)were *** results show that processing parameters significantly affect the formability,microstructure,and micro-hardness of the *** decreasing laser power from 1,900 W to 1,000 W,the relative density is decreased from 99.86%to 90.91%due to the increase of lack-of-fusion;however,with increasing scanning speed,the relative density does not change significantly,but exceeds 99%.In particular,Ti-6.38Al-3.87V-2.43Mo samples of single-track and bulk exhibit a good formability under an input laser power of 1,900 W and a scanning speed of 8 mm·s_(-1),and display the lowest surface roughness(Ra=13.33μm)and the highest relative density(99.86%).Besides,the microstructure of LAM Ti-6.38Al-3.87V-2.43Mo alloy coarsens with increasing laser power or decreasing scanning speed due to the greater input energy reducing the cooling *** coarsening of the microstructure decreases the microhardness of the alloy.

关键词： laser additive manufacturing composition design cluster-plus-glue-atom model microstructure properties

Design for Ti-Al-V-Mo-Nb alloys for laser additive manufacturing based on a cluster model and on their microstructure and properties

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China Foundry 2021年第4期18卷 424-432页

In this study,α+βTi-Al-V-Mo-Nb alloys with the addition of multiple elements that are suitable for laser additive manufacturing(LAM)were designed according to a Ti-6Al-4V cluster *** formula can be expressed as 12[Al-Ti12](AlTi2)+5[Al-Ti14]((Mo,V,Nb)2Ti),in which Mo and Nb were added into the alloys partially instead of V to give alloys with nominal compositions of Ti-6.01Al-3.13V-1.43Nb,Ti-5.97Al-2.33V-2.93Mo,and Ti-5.97Al-2.33V-2.20Mo-0.71Nb(wt.%).The microstructures and mechanical properties of the as-deposited and heat-treated samples prepared via LAM were *** sizes of theβcolumnar grains andαlaths in the Nb-containing samples are found to be larger than those of the Ti-6Al-4V alloy,whereas Mo-or Mo/Nb-added alloys contain finer *** indicates that Nb gives rise to coarsenedβcolumnar grains andαlaths,while Mo significantly refines ***,the single addition of Nb improves the elongation,whereas the single addition of Mo enhances the strength of the *** simultaneous addition of Mo/Nb significantly improves the comprehensive mechanical properties of the alloys,leading to the best properties with an ultimate tensile strength of 1,070 MPa,a yield strength of 1,004 MPa,an elongation of 9%,and micro-hardness of 355 *** fracture modes of all the alloys are ductile-brittle mixed fracture.

关键词： titanium alloy laser additive manufacturing cluster-plus-glue-atom model composition design microstructure mechanical properties

Shearing-force-driven delamination of waste residue into oxidatively stable MXene composites for high-performance Si anode

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Rare Metals 2023年第7期42卷 2226-2237页

作者： Peng Liu zhi-hao zhu Wen Zhang Jia-Yi Liu Zhong Su Xin-Hua Liu Shi-Chun Yang Chao Lai School of Chemistry and Materials Science Jiangsu Normal UniversityXuzhou221116China School of Transportation Science and Engineering Beihang UniversityBeijing100191China

The low yield of MXene is normally related to the delaminating step,contributing to the key technical challenges in moving toward industrial ***,a shearing-force-driven strategy is proposed for re-exfoliating waste MXene residue to prepare oxidatively stable MXene composites in a low-cost manner,where the strong shear stress in the assisted solvent,such as carbon nanotubes(CNTs),chitosan(CS),and polyacrylamide(PAM)aqueous solutions,acts on the surface of MXene(Ti_(3)C_(2)T_(x))through coordination between hydroxyl and Ti atoms,resulting in a rapid and efficient exfoliation of waste Ti_(3)C_(2)T_(x)residue under ***,this formed coordinate bond helps to stabilize the low-valent Ti atoms on the surface of MXene,thereby enhancing the oxidative stability of Ti_(3)C_(2)T_(x).Besides,the CNT@MXene composite is selected to construct a free-standing membrane to encapsulate Si nanoparticles,achieving a high and reversible capacity after 50 *** work supports the concept of valorizing waste and adopts a fluid shear forceassisted method to re-exfoliate waste residues,which greatly reduces the cost of processing and improves the chemical stability of *** importantly,this work has uncovered a new direction for the commercialization of MXene composites and has significantly improved the realworld applications of MXene-based materials.

关键词： Waste residue Shear stress MXene composites Oxidatively stable Si anode

A novel Ti-5.55Al-6.70Zr-1.50V-0.70Mo-3.41Nb-0.21Si alloy designed using cluster-plus-glue-atom model for laser additive manufacturing

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China Foundry 2023年第5期20卷 414-422页

作者： Tian-yu Liu Yan-chun Lou Shuang Zhang zhi-hao zhu Jun Zhao Shi-bing Liu Kun Shi Ning Zhao National Key Laboratory of Advanced Casting Technologies Shenyang Research Institute of Foundry Co.Ltd.CAMShenyang 110022China School of Materials Science and Engineering Beihang UniversityBeijing 100191China School of Materials Science and Engineering Dalian Jiaotong UniversityDalian 116028LiaoningChina School of Materials Science and Engineering Dalian University of TechnologyDalian 116024LiaoningChina

A novel Ti-5.55Al-6.70Zr-1.50V-0.70Mo-3.41Nb-0.21Si alloy was designed using the cluster formula approach(cluster-plus-glue-atom model)and prepared by laser melting deposition(LMD).Its composition formula 12[Al-Ti_(12)](AlTi_(2))+5[Al_(0.8)Si_(0.2)-Ti_(12)Zr_(2)](V_(0.8)Mo_(0.2)Nb_(1)Ti)features an enhancedβ-Ti via co-alloying of Zr,V,Mo,Nb and *** experimental results show that the cluster formula ofαandβphases in the novel alloy are respectivelyα-[Al-Ti_(11.5)Zr_(0.5)](Al_(1)Ti_(2))andβ-[Al_(0.8)Si_(0.2)-Ti_(13.2)Zr_(0.8)](V_(1)Mo_(0.4)Nb_(1.6)),both containing Zr *** fitted composition via the α andβphase cluster formulas has little difference with the actual alloy composition,suggesting that the validity of cluster-plus-glue-atom model in the alloy composition *** hot isostatic pressing(HIP),both the Ti-6Al-4V and the novel alloy by LMD are characterized by prior-βcolumnar grains,while the typicaltexture *** with Ti-6Al-4V,Ti-5.55Al-6.70Zr-1.50V-0.70Mo-3.41Nb-0.21Si alloy exhibits a combination of higher strength(1,056 MPa)and higher ductility(14%)at room temperature and higher strength(580 MPa)at 550℃ after HIP,and can potentially serves as LMD materials.

关键词： additive manufacturing laser melting deposition novel titanium alloy composition design cluster-plus-glue-atom model

Constraints ofξ-moments computed using QCD sum rules on pion distribution amplitude models

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Chinese Physics C 2023年第1期47卷 125-134页

作者：钟涛朱志豪付海冰 School of physics Henan Normal UniversityXinxiang 453007China Department of Physics Guizhou Minzu UniversityGuiyang 550025China Department of Physics Chongqing UniversityChongqing 401331China

To date,the behavior of the pionic leading-twist distribution amplitude(DA)φ2;π(x,μ)-which is a universal physical quantity and is introduced into high-energy processes involving pions based on the factorization theorem-is not completely *** form ofφ2;π(x,μ)is usually described by phenomenological models and constrained by the experimental data on exclusive processes containing pions or the moments computed using QCD sum rules and the lattice QCD ***,an appropriate model is extremely important to determine the exact behavior ofφ2;π(x,μ).In this paper,by adopting the least squares method to fit theξ-moments calculated using QCD sum rules based on the background field theory,we perform an analysis on several commonly used models of the pionic leading-twist DA in the literature;these include the truncation form of the Gegenbauer polynomial series,the light-cone harmonic oscillator model,the form extracted from the Dyson-Schwinger equations,the model from the light-front holographic AdS/QCD,and a simple power-law parametrization form.

关键词： pion distribution amplitude QCD sum rules light-cone harmonic oscillator model

Research progress in Asia on methods of processing laser-induced breakdown spectroscopy data

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Frontiers of physics 2016年第5期11卷 137-149页

作者： Yang-Min Guo Lian-Bo Guo Jia-Ming Li Hong-Di Liu zhi-hao zhu Xiang-You Li Yong-Feng Lu Xiao-Yan Zeng Wuhan National Laboratory for Optoelectronics Huazhong University of Science and Technology (HUST) Wuhan 430074 China

Laser-induced breakdown spectroscopy （LIBS） has attracted much attention in terms of both scientific research and industrial application. An important branch of LIBS research in Asia, the development of data processing methods for LIBS, is reviewed. First, the basic principle of LIBS and the characteristics of spectral data are briefly introduced. Next, two aspects of research on and problems with data processing methods are described： i） the basic principles of data preprocessing methods are elaborated in detail on the basis of the characteristics of spectral data; ii） the performance of data analysis methods in qualitative and quantitative analysis of LIBS is described. Finally, a direction for future development of data processing methods for LIBS is also proposed.

关键词： laser-induced breakdown spectroscopy data preprocessing data analysis

Late Paleozoic to early Mesozoic volcanic-sedimentary history of the southeastern margin of the Central Asian Orogenic Belt: Timing of uplift of the Inner Mongolia paleo-uplift

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Science China Earth Sciences 2025年第1期68卷 297-309页

作者： Wenxing hao Jin-Hui YANG Guang zhu State Key Laboratory of Lithospheric Evolution Institute of Geology and Geophysics Chinese Academy of Sciences School of Resource and Environmental Engineering Hefei University of Technology

The Kulun region is located in the eastern Bainaimiao arc belt on the southeastern margin of the Central Asian Orogenic Belt(CAOB), adjacent to the North China Craton(NCC) to the south. This region records the closure of the PaleoAsian Ocean during the Paleozoic to early Mesozoic and is key to study the tectonic evolution of the northern margin of the *** conducted zircon U-Pb geochronology and Hf isotope analysis of volcanic-sedimentary and intrusive rocks in the Kulun region. The volcanic-sedimentary rocks were previously assigned an early Carboniferous age, but include volcanic rocks with ages of 267–266 Ma and sedimentary rocks with youngest detrital zircon age peaks of 265–244 Ma, which were intruded by a granite with an age of 242 Ma. This indicates that these rocks are actually middle Permian to Middle Triassic in age(267–242Ma) and correspond to the Qingfengshan and Liujiagou formations. Moreover, two volcanic rock samples have high εHf(t) values(+1.6 to +16.1) and relatively young two-stage Hf model ages(1095–327 Ma), indicating their sources associated with the CAOB. The age spectra and Hf isotopic characteristics of detrital zircons from the sedimentary rocks suggest that, during the middle Permian to Middle Triassic, the sedimentary provenance in the Kulun region was mainly the CAOB. However, by the Early Jurassic, the provenance changed to the NCC(i.e., the Inner Mongolia Paleo-uplift, IMPU). This result, combined with the development of a series of conglomerates on the northern margin of the NCC in the Late Triassic(i.e., Xingshikou, Xiaoyingzi,and Xiaohekou formations), indicates the Kulun region experienced an abrupt change in paleogeography during the Late Triassic, with the IMPU undergoing significant uplift and thus becoming the main sediment source in the Kulun region. Based on the Late Triassic alkaline igneous belt(235–215 Ma) in the IMPU, we speculate that this uplift was caused by detachment of the southward-subducting Paleo-Asian oceanic

关键词： Central Asian Orogenic Belt the North China Craton Zircon geochronology Hf isotopes Inner Mongolia Paleo-uplift