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On The hardening of The Spectrum of High-Energy Particles Formed in Heavy-Ion Collisions Considered within The Framework of The Hydrodynamic Approach

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Journal of Modern Physics 2011年第1期2卷 8-11页

作者： Alexander T. D’ yachenko Konstantin A. Gridnev 不详

The emission of high-energy particles in 16O + 197Au collisions at energy 20 MeV / nucleon is considered within the framework of the time evolution of a hot spot taking into account the hydrodynamic compression and expansion stages. In addition, the evaporation of the particles that are formed in the early (hot) stage of the evolution of the hot spot is included in the calculation of the spectrum. This leads to a hardening of the particle spectrum in its high-energy part, which is in agreement with experimental data.

关键词： hardening of The Spectrum High-Energy Particles Heavy-Ion Hydrodynamics Hot Spot Fermi-Liquid Freeze-Out Density Skyrme-Type Interaction Double Differential Cross-Section Time Evolution Evaporation

Effect of Normalizing and hardening on Mechanical Properties of Spring

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Journal of Minerals and Materials Characterization and Engineering 2012年第8期11卷 832-835页

作者： O. R. Adetunji P. O. Aiyedun S. O. Ismaila M. J. Alao Mechanical Engineering Department College of Engineering Federal University of Agriculture Abeokuta Abeokuta Ogun State Nigeria

This study was carried out to investigate the effect of heat treatment (Normalizing and hardening) on the mechanical properties of springs. The springs were made from mild steel rod having a diameter of 6 mm, a total of 15 springs were made. The springs were then subjected to various heat treatment processes which included;normalizing, hardening and tempering. The heat treated springs were then subjected to various test in other to determine their mechanical properties, these included;impact toughness test, hardness test and tension test. The normalized spring had more strength, was harder and was much tougher than both the annealed and as received springs. The water quenched springs were the hardest of all the heat treated springs, were very brittle and had the lowest percentage elongation. Their strength was also lower than that of the normalized and as received springs. The water quenched and tempered springs had better mechanical properties required for spring making, they had the optimum combination of hardness, strength and toughness when compared with the other heat treated springs.

关键词： Normalizing hardening Tempering Impact Toughness Tension Spring

The effects of cold-hardening on Rubisco in rice seedling leaves

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Chinese Rice Research Newsletter 1998年第1期6卷 7-8页

作者： ZHAOJun WANGYirou LIMeiru LIUHongxian MIAOYougang LILiren SouthChinaInstofBotany AcademiaSinicaGuangzhou510650 ShanghaiInstofPlantPhysiology AcademiaSinicaShanghai200032China

Rubisco is a key enzyme which controls theprocess of photosynthesis and phototespi-ration.It is very abundant in the leaf and isvery sensitive to many environmental factors.we studide the changes,caused by cold-hard-ening and chilling stress,in activity,Proteincontent,and the characters of Rubisco in riceseedlings(Tesanal 2).The treatment of cold-hardening at 14℃and under a PFD(photo flux density)of 75

关键词： seedling Rubisco chilling hardening photosynthesis abundant characters

Strength properties and evolution laws of cracked sandstone samples in re-loading tests

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International Journal of Mining Science and Technology 2020年第2期30卷 251-258页

作者： Yijiang Zong Lijun Han Qinbin Meng Yingchao Wang State Key Laboratory for Geomechanics and Deep Underground Engineering China University of Mining&TechnologyXuzhou 221116China School of Transportation Engineering Jiangsu Vocational Institute of Architectural TechnologyXuzhou 221116China

To study the strength properties and evolution laws of cracked sandstone samples in re-loading tests,strength and damage evolution properties of intact sandstone samples were first analyzed through the triaxial compression tests carried on TAW-2000 microcomputer control electro-hydraulic servo rock triaxial test system.Damage evolution models were established based on dilatancy properties realizing the real-time and quantitative evaluation of samples damage state in loading process.On this basis,samples with different damage were obtained by pre-peak,peak point,post-peak and residual strength stage unloading tests in the loading process of intact samples.The characteristics of the stress-strain curves and strength evolution laws were studied through the re-loading tests of samples with different damage under different stress states.The experimental results showed that the slope of stress-strain curves,peak strength and residual strength of cracked samples increased linearly with confining pressure and decreased linearly with damage.The equivalent cohesion decreased with damage in the exponential decay curves.The mechanics properties of samples transformed from strain softening to strain hardening with damage.

关键词： Rock mechanics Damage Re-loading Strength characteristics Strain hardening

Carbides precipitation and their evolution of Cr15Co10Mo5-alloyed heat-resistant bearing steel after tempering at different temperatures

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Journal of Iron and Steel Research(International) 2019年第10期26卷 1096-1105页

作者： Mao-guo Xiao Xin-yang Lü Dong-hui Li Shao-hong Li Kun-yu Zhao Mao-sheng Yang School of Material Science and Engineering Kunming University of Science and TechnologyKunming 650093YunnanChina Institute for Special Steels Central Iron and Steel Research InstituteBeijing 100081China

The carbides precipitation and their evolution at elevated tempering temperature in Crl5Col0Mo5-alloyed heat-resistant bearing steel were investigated by means of the transmission electron microscope.The results show that there is no carbide precipitated from the martensitic matrix when the sample was tempered at 480℃.However,when the sample was tempered at 540℃,a large number of stable spherical M6C carbides precipitated in the test steel.Nevertheless,there are three types of carbides precipitated from the matrix including M6C,M2C and M23C6 carbides when the tempering temperature reached 600℃.The mechanical properties also present a correlation with the evolution of carbides during tempering at different temperatures.This indicates that the strengthening mechanism of the steel is mainly attributed to the precipitation of carbides and their evolution,including the morphologies and types of carbides at different temperatures.In addition,the austenitic layers with a thickness of about 30 nm have been obtained between the martensite laths after tempering at 600℃.The austenitic layers will produce transformation-induced plasticity effects to improve the toughness of the steel.

关键词： High-temperature bearing steel Carbide evolution Phase diagram Diffusion coefficient Secondary hardening Austenitic layer

Deformation behavior of a TiZr-based metallic glass composite containing dendrites in the supercooled liquid region

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Journal of Materials Science & Technology 2020年第2期37卷 64-70页

作者： Longjun Wu Zhengwang Zhu Dingming Liu Huameng Fu Hong Li Aimin Wang Hongwei Zhang Zhengkun Li Long Zhang Haifeng Zhang Shenyang National Laboratory for Materials Science Institute of Metal ResearchChinese Academy of SciencesShenyang110016China School of Materials Science and Engineering University of Science and Technology of ChinaHefei230026China Dongguan Eontec Co. LtdDongguan523662China Shenyang Amorphous Metal Manufacturing Co. Ltd.Shenyang110000China

The deformation behavior of a TiZr-based bulk metallic glass composite(BMGC)was characterized in the supercooled liquid region(SLR)from 623 K to 693 K.It was observed that the alloy exhibits the deformation behavior from work softening at low temperatures to work hardening at high temperatures.The yield stress and overshoot stress decrease remarkably with the increase of temperature,accompanied by superplasticity.The results showed that the crystallization occurred in the amorphous matrix for the post-deformation samples and the volume fraction of the corresponding crystallization products increased with increasing testing temperature.It is implied that the work hardening behavior was closely associated with the crystallization of the amorphous matrix.The tensile stress can accelerate the crystallization of amorphous matrix and the martensitic transformation of dendrite phases,which implies that the thermal stability of the alloy decreases under tension.These findings shed light on designing new BMGCs with high mechanical performance as well as the good SLR formability.

关键词： Bulk metallic glass composite Tension Work hardening ability Superplasticity Crystallization

Microstructural characteristics and aging response of Zn-containing Al-Mg-Si-Cu alloy

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International Journal of Minerals,Metallurgy and Materials 2013年第7期20卷 659-664页

作者： Yuan-hua Cai Cong Wang Ji-shan Zhang State Key Laboratory for Advanced Metals and Materials University of Science and Technology Beijing

Al-Mg-Si-Cu alloys with and without Zn addition were fabricated by conventional ingot metallurgy method. The microstructures and properties were investigated using optical microscopy （OM）, field emission scanning electron microscopy （FE-SEM）, transmission electron microscopy （TEM）, tensile test, hardness test, and electrical conductivity measurement. It is found that the as-cast A1-Mg-Si-Cu-Zn alloy is composed of coarse dendritic grains, long needle-like ~/5-A1FeSi white intermetallics, and Chinese script-like a-A1FeSi compounds. During high temperature homogenization treatment, only harmful needle-like ^-A1FeSi phase undergoes fragmentation and spheroidizing at its tips, and the destruc- tive needle-like 5-phase does not show any morphological and size changes. Phase transitions from ^-A1FeSi to ^-A1FeSi and from 6-A1FeSi to [3-A1FeSi are also not found. Zn addition improves the aging hardening response during the former aging stage and postpones the peak-aged hardness to a long aging time. In T4 condition, Zn addition does not obviously increase the yield strength and decrease the elongation, but it markedly improves paint-bake hardening response during paint-bake cycle. The addition of 0.5wt% Zn can lead to an increment of 99 MPa in yield strength compared with the value of 69 MPa for the alloy without Zn after paint-bake cycle.

关键词： aluminum alloys zinc hardening mechanical properties microstructure

Effect of heat treatment on cyclic deformation properties of Fe-26Mn-10AI-C steel

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Journal of Iron and Steel Research(International) 2019年第2期26卷 200-210页

作者： He Li Jian-ping Zhao Zhan-yu Wang Li Ding School of Mechanical and Power Engineering Nanjing Tech UniversityNanjing 211816JiangsuChina Jiangsu Key Lab of Design and Manufacture of Extreme Pressure Equipnient Nanjing 211816JiangsuChina

Fully reversed tensile-compression low-cycle fatigue tests were performed at room temperature under strain amplitude of 0.4%.The monotonic tensile results show that Fe-26Mn-10A1-C steels are fully austenite and(he optimal combination of ultimate tensile strength and total elongation was present at 950°C with 65 GPa%.The fatigue results show that the specimen at 1050°C has the maximum fatigue life of 162,000 cycles,which is much longer than twinning-induced plasticity(TWIP)steels of the same strain amplitude.The hot-forging specimen shows high similarity with TWIP steels with rapid initial cyclic hardening followed by cyclic softening and cyclic saturation.After solution heat treatment,it is noteworthy that,after rapid initial cyclic softening,another rapid cyclic hardening and a following decrease with fluctuation were observed at 1000°C.It is reas on able to believe that it is caused by K-carbides precipitated during cyclic deformation.Anolher interesting phenomenon is cyclic stress subsidence observed at 1050°C during its saturation stage at the last quarter of the fatigue life,and the span is about 12.5%of whole fatigue life.

关键词： Fe-Mn-AI-C steel Low-cycle fatigue Cyclic hardening Cyclic softening Cyclic stress subsidence

High He-ion irradiation resistance of CrMnFeCoNi high-entropy alloy revealed by comparison study with Ni and 304SS

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Journal of Materials Science & Technology 2019年第3期35卷 300-305页

作者： Lixin Yang Hualong Ge Jian Zhang Ting Xiong Qianqian Jin Yangtao Zhou Xiaohong Shao Bo Zhang Zhengwang Zhu Shijian Zheng Xiuliang Ma Shenyang National Laboratory for Materials Science Institute of Metal Research Chinese Academy of Sciences School of Material Science and Engineering University of Science and Technology of China School of Energy Research Xiamen University School of Material Science and Engineering Lanzhou University of Technology

High entropy alloys(HEAs) have presented potential applications in nuclear power plants owing to their novel atomic structure based high irradiation resistance. However, understanding of He-ion irradiation of HEAs is still lacking. In this work, we reveal He-ion irradiation resistance of HEA CrMnFeCoNi by comparison study with a pure Ni and a 304 stainless steel(304SS). It is found that the damage structure in the three materials can be characterized with He bubbles and stacking faults/stacking fault tetrahedrons((SFs/SFTs), which show a similar depth distribution after He-ion irradiation at both RT and 450℃.Although the He bubbles have a similar size about 2nm after irradiation at RT, the He bubble sizes of the HEA, 304SS, and Ni increase to 4.0±0.9,5.3±1.0 and 6.7 ±1.0 nm after irradiation at 450℃, respectively. Moreover, the density of SFs/SFTs displays in an order of Ni hardening. Thus, the HEA CrMnFeCoNi possesses the smallest He bubble size, the densest SFs/SFTs, and the highest hardening, indicating the best structural stability, as well as the best He-ion irradiation resistance, which can be attributed to its low mobility of He atoms and point defects.

关键词： High entroy alloy(HEA) CrMnFeCoNi He-ion Irradiation hardening