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Combination of Instrumented Nanoindentation and Scanning Probe Microscopy for Adequate Mechanical Surface Testing

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Journal of Materials Science & Technology 2009年第1期25卷 63-68页

作者： Enrico Tam Mikhail Petrzhik Dmitry Shtansky Marie-Paule Delplancke-Ogletree Université Libre de Bruxelles moscow state institute of steel and alloys

The elastic indentation modulus and hardness of standard bulk materials and advanced thin films were determined by using the nanoindentation technique followed by the Oliver- Pharr post-treatment. After measurements with different loading/unloading schemes on chemically polished bulk titanium a substantial decrease of both modulus and hardness vs an increasing loading time was found. Then, hard nanostructured TiBN and TiCrBN thin films deposited by magnetron sputtering （using multiphase targets） on substrates of high roughness （sintered hard metal） and low roughness （silicon） were studied. Experimental modulus and hardness characterized by using two different nanoindenter tools were within the limits of standard deviation. However, a strong effect of roughness on the spread of the experimental values was observed and it was found that hardness and elastic indentation modulus obeyed a Gaussian distribution. The experimental data were discussed together with scanning probe microscopy （SPM） images of typical imprints taken after the nanoindentation tests and the local topographyls strong correlation with the results of nanoindentation was described.

关键词： Nanoindentation Thin films Coatings Scanning probe microscopy

Achieving strength-ductility synergy in novel paramagnetic Fe-based medium-entropy alloys through deep cryogenic deformation

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Rare Metals 2024年第9期43卷 4493-4507页

作者： Hu-Wen Ma Yan-Chun Zhao Li Feng Tian-Zeng Liu Zhi-Qi Yu Bo Jin Wang-Chun Duan Peter K.Liaw Dong Ma state Key Laboratory of Advanced Processing and Recycling of Non-Ferrous Metals Lanzhou University of TechnologyLanzhou 730050China Wenzhou Pump and Valve Engineering Research institute Lanzhou University of TechnologyWenzhou 325105China Iron and steel Research institute Jiuquan Iron and Steel CorporationJiayuguan 735100China Lanzhou Resources and Environment Voc-Tech University Lanzhou 730123China Department of Materials Science and Engineering The University of TennesseeKnoxvilleTN 37996-2200USA Neutron Science Center Songshan Lake Materials LaboratoryDongguan 523808China

Cryogenic pre-deformation treatment has been widely used to effectively improve the comprehensive mechanical properties of steels and novel ***,the dislocation evolution and phase transformation induced by different degrees of deep cryogenic deformation are not yet fully *** this study,the effects of multiple cryogenic pre-treatments on the mechanical properties and deformation mechanisms of a paramagnetic Fe_(63.3)Mn_(14-)Si_(9.1)Cr_(9.8)C_(3.8)medium-entropy alloy(MEA)were investigated,leading to the discovery of a pretreated MEA that exhibits exceptional mechanical properties,including a fracture strength of 3.0 GPa,plastic strain of 26.1%and work-hardening index of *** addition,X-ray diffraction(XRD)and transmission electron microscopy(TEM)analyses revealed that multiple cryogenic pre-deformation treatments significantly increased the dislocation density of the MEA(from 9×10^(15)to 4×10^(16)m^(-2)after three pretreatments),along with a transition in the dislocation type from predominantly edge dislocations to mixed dislocations(including screw-and edge-type dislocations).Notably,this pretreated MEA retained its paramagnetic properties(μ_(r)<1.0200)even after *** calculations showed that cryogenic pretreatment can significantly reduce the stacking fault energy of the MEA by a factor of approximately four(i.e.,from 9.7 to2.6 m J·m^(-2)),thereby activating the synergistic effects of transformation-induced plasticity,twinning-induced plasticity and dislocation strengthening *** synergistic effects lead to simultaneous strength and ductility enhancement of the MEA.

关键词： Deep cryogenic transformation Iron-based medium-entropy alloys Dislocation evolution Phase transformation Stacking fault energy

Enthalpy of formation of quasicrystalline phase and ternary solid solutions in the Al-Fe-Cu system

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Rare Metals 2006年第5期25卷 608-613页

作者： I.A.Tomilin S.D.Kaloshkin V.V.Tcherdyntsev moscow state institute of steel and alloys (Technologycal University) 119049 Leninsky prosp.4MoscowRussia

Standard enthalpies of formation of quasicrystalline phase and the ternary solid solutions in the Al-Fe-Cu system and the intermetaUic compound FeAI were determined by the means of solution calorimetry. The quasicrystalline phase was prepared using two different methods. The first method （I） consisted of ball milling the mixture of powders of pure aluminum copper and iron in a planetary mill with subsequent compacting by hot pressing and annealing. The second method （Ⅱ） consisted of arc melting of the components in argon atmosphere followed by annealing. The latter method was used for preparing the compound FeAl and the solid solutions. The phases were identified using the XRD method. The enthalpy of the formation was determined for the quasicrystalline phase of the composition Al62Cu25.5Fe12.5 and the temary BCC solid solutions Al35Cu14Fe51, Al40Cu17Fe43, and Al50.4Cu19.6Fe30. The measured enthalpy of formation of the intermetallic compound FeAl is in good agreement with the earlier published data. The enthalpies of formation of the quasicrystalline phases prepared using two different methods are close to each other, namely, -22.7±3.4 （method I） and -21.3±2.1 （method Ⅱ） kJ/mol.

关键词： enthalpy of formation calorimetry quasicrystals Al-Fe-Cu

Graphite Crystallization in Ductile Iron

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Journal of Rare Earths 1992年第2期10卷 130-135页

作者： Kozlov L.Ya Vorobyev A.P moscow steel and alloys institute MoscowRussia

The authors studied effect of cerium and lanthanum on crystallization parameters anti structure formation of cast *** was found that REM additives increased duration and temperature range of eutectic transforma- tion and prevented primary graphite *** change in crystallization pattern of iron is due to the REM effect on graphite nucleation and *** the basis of microprobe analysis of REM distribution and the DTA results,a mechanism of the REM effect on iron crystallization and graphite morphology was suggested.

关键词： Graphite crystallization Rare earth Ductile iron

The first order phase-transition of polycrystal solid surfaces with nanothickness

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Rare Metals 2006年第6期25卷 709-714页

作者： Y.A. Minaev moscow state steel & alloys institute and Russian Academy of Natural Science Leninsky prt.4 Moscow 119049 Russia

The fundamental equations of thermodynamics of a film have been used for describing a fundamental property of solid crystalline materials i.e. the first-order phase transition on the grain boundaries by the formation of two-dimensional liquid. The generalized equation that is obtained is used for calculating the premelting temperature of any metal, which has a value in the range of 0.55-0.86 of the melting point. The experimental diffusion coefficient of nitrogen in steel at premelting temperature is the same as in the liquid phase. The described phenomenon of phase transition on the grain boundaries decreases in case of radical modification of the existing process engineering of handling metals. It also provides a precise physical explanation to the super plasticity of fine-structure metal alloys.

关键词： thermodynamics of premelting nitrogen diffusion nitrided coatings structure high-temperature superplasticity

Interaction mechanism between BaZrO_(3)/Y_(2)O_(3) refractory and Ti_(2)Ni alloy melts

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Journal of Iron and steel Research International 2024年第6期31卷 1376-1388页

作者： Xiao Hou Guang-yao Chen Jian Liu Ming-rui Lv Fei-hai Yu Qi-sheng Feng Rong-bin Li Xiong-gang Lu Chong-he Li state Key Laboratory of Advanced Special steel and Shanghai Key Laboratory of Advanced Ferromeallurgy and School of Materials Science and Engineering Shanghai UniversityShanghai 200072China Shanghai Special Casting Engineering Technology Research Center Shanghai 201605China Zhejiang institute of Advanced Materials Shanghai UniversityJiashan 314100ZhejiangChina School of Materials Science and Engineering Shanghai DianJi UniversityShanghai 201306China

The titanium alloys with highly chemical activity require stable crucible refractories that can withstand the erosion of alloy *** phase composition and microstructure are crucial factors that affect the stability of the refractory *** effect of Y_(2)O_(3) on the composition and microstructure of BaZrO_(3) crucible was systematically investigated,and the improved mechanism of the stability of BaZrO_(3)/Y_(2)O_(3) crucible was clarified in comparison with the BaZrO_(3) *** results showed that the erosion layer thickness of the BaZrO_(3)/Y_(2)O_(3) crucible was only 63μm,which was far less than that in the BaZrO_(3) crucible(485μm),and the erosion layer in the BaZrO_(3)/Y_(2)O_(3) crucible also exhibited a higher density than that in the BaZrO_(3) *** the sintering,Y_(2)O_(3) could improve the densification of the BaZrO_(3) crucible due to the solid solution effect between Y_(2)O_(3) and ZrO_(2),which also caused the evaporation of BaO,resulting in the generation of a Y_(2)O_(3)(ZrO_(2))film on the surface of the ***,the Y_(2)O_(3)(ZrO_(2))had higher thermodynamic stability than Y_(2)O_(3),confirming that the BaZrO_(3)/Y_(2)O_(3) crucible with high density exhibited a superior erosion resistance to titanium *** dual-phase structure provides a strategy to design a long-life and stable refractory for melting titanium alloys.

关键词： Barium zirconate Yttrium oxide Dual-phase refractory Titanium alloy Interaction

A STUDY ON THE BEHAVIOUR OF GALLIUM IN THE IRONMAKING PROCESS

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Acta Metallurgica Sinica(English Letters) 2003年第2期16卷 78-83页

作者： L.Savov S.Garonin O.Ivanov Y.S.Fusfin D.Janke institute of Iron and steel Technology Freiberg University of Mining and TechnologyD-09596 FreibergGermany moscow state institute of steel and alloys(MISIS) 4 Leninsky Prospekt117936 MoscowRussia Manuscript received 9 May 2002

Gallium is a valuable rare metal which is mainly being used in the production of GaAs. The demand for gallium is increasing but production is limited since gallium is extracted only as a by-product of bauxite processing. On the other hand coal, ironmaking coke and iron ore gangue contain traces of gallium. However little is known about the behaviour of gallium in ironmaking. The aim of the study is to clarify the distribution of gallium between hot metal, slag and top gas by means of laboratory experiments. It was found that Ga2O3 is not stable in blast furnace slags and that gallium is retained in hot metal. Vacuum distillation experiments with hot metal showed that gallium is not transferred to the gas phase. Data on the input and output of gallium at two industrial blast furnaces, as well as chemical analyses of the gallium content of several cokes are presented, too.

关键词： gallium thermodynamics ironmaking blast furnace coke

Effect of Cerium on Morphology of Phosphide Eutectic

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Journal of Rare Earths 2000年第1期18卷 39-42页

作者：陈贵如梁吉魏秉庆吴德海 Department of Mechanical Engineering Tsinghua University Beijing 100084 China institute of steel and alloys Moscow 117936 Russian Federation

The phosphide eutectic formation process in high purity Fe-4. 6% C alloy, in which 0.02%-1.0% P was added, was studied with DTA, SEM and EDS, and the effect of cerium on the morphology of phosphide eutectic in the ternary Fe-C-P alloy was also investigated. The results show that the ternary phosphide eutectic with the addition of 0.04% P is formed at low cooling rate. After cerium is added, the morphology of phosphide eutectic is changed from non-continuous or continuous distribution net to round or nodular form locating along the eutectic cell boundaries.

关键词： rare earths phosphorus phosphide eutectic eutectic cell

Electronic-scale assessment of high-temperature oxidation mechanisms in a novel Fe-based alloy

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Journal of Iron and steel Research International 2024年第4期31卷 982-997页

作者： Wei-di Luo Ting-ping Hou Xuan Liang Dong Zhang Heng-fu Lin Yu Li Tian-liang Zhao Cheng-yang Hu Serhii Yershov Kai-ming Wu The state Key Laboratory of Refractories and Metallurgy.Wuhan University of Science and Technology.Wuhan 430081 HubeiChina Hubei Province Key Laboratory of Systems Science in Meallurgial Process Wuhan University of Science and Technology.Wuhan 430081.Hubei.China International Research institute for steel Technology Wuhan University of Science and Technology.Wuhan 430081.HubeiChina Collaborative Innovation Center for Advanced steels w uhan University of Science and Technology.Wuhan 430081.HuleiChina

The development of alloys with high antioxidation performance is limited by the ambiguous details of the oxidation ***,based on the structures of internal oxides detected by high-resolution transmission electron microscopy,a hybrid method combining first-principles calculation,climb image nudged elastic band method and quasi-harmonic Debye model has been implemented to explain the oxidation mechanism with an emphasis on the origin of delamination and *** results showed that the delamination of oxides corresponds to the acceleration of diffusion of Cr element caused by lamellar *** reduction in the cracking occurrence at high temperature mainly results from the smaller bulk modulus of ***,the stronger chemical bonds promoted by lamellar structures also correspond to the higher crackingresistance.

关键词： Oxidation Crystal structure Diffusion Cracking-First-principles calculation