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Distribution of Be in a Ti-Based Bulk Metallic Glass Composite Containing B-Ti

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Journal of Materials Science & Technology 2017年第7期33卷 708-711页

作者： L.Zhang W.Q.li Z.W.Zhu h.M.Fu h.li Z.K.li h.W.Zhang A.M.Wang h.F.Zhang Shenyang National Laboratory for Materials Science Institute of Metal Research Chinese Academy of Sciences 110016 Shenyang China

In order to obtain a glassy matrix during quenching, Be is often selected as a constituent of the compositions of Ti/Zr-based bulk metallic glass composites（BMGCs）. The in situ formed β phase in Be-bearing BMGCs was reported to be Be-free. however, a thorough investigation of the distribution of Be in BMGCs is still missing to date. In this work, the distribution of Be in a Ti_（47.5）Zr_（33）Cu_（5.8）Co_3Be_（12.5）（at.%） BMGC was studied by the secondary ion mass spectrometry（SIMS） and the electron energy loss spectroscopy（EELS）.It is found that Be almost totally dissolves in the glassy matrix, but a very weak intensity of Be in β phase is still detectable by SIMS, and the content of Be in β-Ti is estimated to be about 0.3 at.%. Based on the recently established two-phase quasi-equilibrium of BMGCs, the distinct solubility of Be in the glassy matrix and in β-Ti has been explained.

关键词： Bulk metallic glass(BMG) Metallic glass composite Beryllium Quasi-equilibrium

INFLUENCE OF hEAT TREATMENT ON OXIDATION PROPERTIES OF C/C COMPOSITES FABRICATED BY hIGh PRESSURE IMPREGNATION CARBONIZATION

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Acta Metallurgica Sinica(English Letters) 2004年第4期17卷 426-430页

作者： Q.Chen h.J.li A.J.li h.M.han K.Z.li School of Materials Science and Engineering Northwestern Polytechnical University Xi'an 710072 ChinaSchool of Materials Science and Engineering Northwestern Polytechnical University Xi'an 710072 ChinaSchool of Materials Science and Engineering Northwestern Polytechnical University Xi'an 710072 ChinaSchool of Materials Science and Engineering Northwestern Polytechnical University Xi'an 710072 ChinaSchool of Materials Science and Engineering Northwestern Polytechnical University Xi'an 710072 China

Felt base carbon/carbon composites fabricated by super-high pressure impregnation carbonization process (SPIC) were heat treated at high temperature 2773K. The oxidation properties of felt base carbon/carbon composites were investigated at different temperatures (773-1173K), and the microstructures of carbon/carbon composites were studied by SEM and X-ray diffraction. The experimental results showed that the inter-laminar distance of (002) plane (d002) deceased while the microcrystalline stack height (Lc) increased. The oxidation rate of felt base carbon/carbon composites was invari-able at certain temperatures. The oxidation mechanism of carbon/carbon composites changed remarkably at the oxidation temperature 973K. At the initial oxidation stage of carbon/carbon composites, carbon matrix was oxidized much more rapidly than carbon felt.

关键词： carbon/carbon composites high pressure impregnation carbonization high temperature heat treatment oxidation mi-crostructure

New ductile laminate structure of Ti-alloy/Ti-based metallic glass composite with high specific strength

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Journal of Materials Science & Technology 2018年第4期34卷 708-712页

作者： D.li Z.W.Zhu A.M.Wang h.M.Fu h.li h.W.Zhang h.F.Zhang Shenyang National Laboratory for Materials Science Institute of Metal Research Chinese Academy of Sciences

Bulk laminate structure of Ti-alloy/Ti-based metallic glass composite （MGC） was prepared by melting a preform of alternate stack-up foils in the high vacuum atmosphere. The composite demonstrates a good combination of yield strength （-1618MPa）, plasticity （-4.3%） and specific fracture strength （384 × 10^3 N m kg^-1 ） in compression. The maintained yield strength results from the unique microstruc- ture composed of the Ti layer, the solution layer with gradient structure and the MGC layer. Such a multilayer structure effectively inhibits the propagation of shear band, leading to the enhanced plastic- ity. Those extraordinary properities suggest that combining ductile lamella with brittle metallic glass （MG） by such a lay-up method can be an effective way to improve mechanical properties of MG.

关键词： Laminate composite Metallic glass Specific strength Plasticity

NANO-MULTILAYERS WITh hIGh PERPENDICULAR ANISOTROPY FOR MAGNETIC RECORDING

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Acta Metallurgica Sinica(English Letters) 2003年第4期16卷 261-265页

作者： T.Yang B.h.li DepartmentofMaterialsPhysics UniversityofScienceandTechnologyBeijingBeijing100083China InformationStorageMaterialsLaboratory ToyotaTechnologicalInstituteNagoya468-8511JapanManuscriptreceived25November2002

(FePt/Ag)n nano-multilayers were deposited on MgO (100) single crystal with laser ablation and then subjected to annealing. FePt L1o grains with (001) texture and thus a large perpendicular magnetic anisotropy constant Ku of the order of 106 J/m3 were formed. A thick Ag layer is found to be favorable for decreasing the dispersion of the easy axis for magnetization. The measurement of time decay of magnetization gave rise to a small activation volume of the order of 10-25m3, showing the promising of being the recording medium for future high density perpendicular recording.

关键词： recording media perpendicular magnetic anisotropy activation volume

Ablation behavior of(ZrC/SiC)_(3)alternate coating prepared on sharp leading edge C/C composites by CVD

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Journal of Materials Science & Technology 2022年第20期115卷 129-139页

作者： B.li h.J.li X.Y.Yao X.F.Tian Y.J.Jia G.h.Feng State Key Laboratory of Solidification Processing Northwestern Polytechnical UniversityXi׳an 710072China

A(ZrC/SiC)_(3)alternate coating was deposited on sharp leading edge(SLE)C/C composites by chemical vapor deposition(CVD).The ablation behavior was examined via oxyacetylene torch with heat flux of 2.38 MW/m^*** results indicated that the alternate coating exhibited great ablation resistance,providing an effective protection for C/C *** initial rapid heating stage,the(ZrC/SiC)_(3) alternate coating can relieve thermal stress,avoiding the peeling of coating and keeping an intact coating *** subsequent ablation,the Si C layers in central region were consumed rapidly,leaving layered *** stacked ZrO_(2) layers were reserved with the assistance of the release of thermal stress by interspaces,offering a great anti-scouring *** transition and border regions,the alternate Si C layers can delay oxygen erosion of inner coating and C/C substrate by the formation of SiO_(2).It is believed that the results would be helpful for the design and application of anti-ablation coatings on SLE C/C composites.

关键词： Alternate coating ZrC/SiC Sharp leading edge Chemical vapor deposition C/C composites

Shear band evolution and mechanical behavior of cold-rolled Zr-based amorphous alloy sheets:An in-situ study

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Journal of Materials Science & Technology 2024年第14期181卷 115-127页

作者： C.Y.Zhang Z.W.Zhu S.T.li Y.Y.Wang Z.K.li h.li G.Yuan h.F.Zhang School of Metallurgy Northeastern UniversityShenyang 110819China Shi-changxu Innovation Center for Advanced Materials Institute of Metal ResearchChinese Academy of SciencesShenyang 110016China The State Key Laboratory of Rolling and Automation(RAL) Northeastern UniversityShenyang 110819China

Cold rolling process can regulate the microstructure and mechanical properties of amorphous alloys,but it is still a challenging task to reveal their microscopic ***,we designed an in-situ SEM observation device for the cold rolling process of amorphous alloy,and visually observed the formation and evolution of shear bands during single-pass and multi-pass rolling process of the Zr_(55)Cu_(30)Al_(10)Ni_(5)amorphous alloy *** is found that the evolution process of shear bands in the rolling process of amorphous alloy shows heritability,which is mainly reflected in two aspects:one is that the shear band formation pattern in the single-pass rolling process is more inclined to inherit the previous shear band formation pattern;the other is that the shear deformation is more likely to occur in the pre-existing shear bands in the multi-pass rolling *** rule can be used to guide the controlled genera-tion of shear bands in amorphous ***,we emphasized the importance of pre-existing shear band orientations and systematically investigated the mechanical behavior of the amorphous alloys with pre-existing shear bands by in-situ SEM *** is found that the mechanical properties of the as-rolled amorphous alloys are determined by the competition between the work-softening of the pre-existing shear band itself and the work-hardening caused by the blocking effect of the pre-existing shear bands on the shear *** on this,we enhance the tensile fracture strength and the tensile ductility of the amorphous alloy by adjusting the orientation of the pre-existing shear bands parallel to the tensile stress axis so that the pre-existing shear bands prevent the linear propagation and destruction of the new shear bands.

关键词： Amorphous alloy Cold rolling Shear band Mechanical behavior In-situ study Plasticity

ThE　SYNThESIS　OF　O－MONOSACChARIDYL－METhOXYCARBONYLPhOSPhONAMIDATES　BY　ARBUZOV　REACTION

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Chinese Chemical Letters 1995年第1期6卷 23-26页

作者： Chen, RY Chen, XR li, h Nankai Univ Inst Elementoorgan Chem Tianjin 300071 Peoples R China

For the synthesis of O-monosaccharidyl-methoxycarhon a new method in which Arbuzov reaction of monosaccharidylphosphoramidite with methyl chloroformate is the key *** reported. Thus,a number of novel O-monosaccharidyl...

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Microstructure and Properties of WB_(2)/Cr Multilayer Films with Different Bilayer Numbers Deposited by Magnetron Sputtering

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Acta Metallurgica Sinica(English Letters) 2022年第4期35卷 693-702页

作者： W.B.Shi Y.M.liu W.h.li T.li h.Lei J.Gong C.Sun Shi-Changxu Innovation Center for Advanced Materials Institute of Metal ResearchChinese Academy of SciencesShenyang 110016China School of Materials Science and Engineering University of Science and Technology of ChinaShenyang 110016China College of Materials Science and Engineering Xi'an Shiyou UniversityXi'an 710065China

The influence of the bilayer number on the microstructure,mechanical properties,adhesion strength and tribological behaviors of the WB_(2)/Cr multilayer films was systematically investigated in the present *** groups of WB_(2)/Cr films with the same modulation ratio were synthesized by magnetron sputtering *** crystalline structure of the films was determined by X-ray *** morphologies and the microstructure of the films were observed by scanning electron microscopy,atomic force microscopy and transmission electron ***,Nano indenter,scratch tester and ball-on-disc tribometer were used to evaluate the mechanical and tribological *** bilayer numbers varied from 5 to 40,the hardness increased first and then decreased with the maximum hardness of 33.9 GPa when the bilayer number is *** h/E^(*)and h^(3)/E^(*2)values calculated to evaluate the fracture toughness showed the similar changing trend with *** adhesion strength reached the maximum of 67 N when the bilayer number is *** surface roughness and friction coefficient decreased with increasing bilayer *** wear mechanism was also investigated,and the results suggested that the multilayer film with bilayer number of 30 exhibited the best wear resistance(1.78×10^(–7)mm^(3)/Nm),benefiting from the contribution of high hardness,fracture toughness and adhesion strength.

关键词： WB_(2)/Cr multilayer Magnetron sputtering Bilayer number Tribological behavior

Oxidation,Mechanical and Tribological Behaviors of the Ni/cBN Abrasive Coating-Coated Titanium Alloys

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Acta Metallurgica Sinica(English Letters) 2021年第7期34卷 1007-1020页

作者： Y.D.liu J.h.liu W.S.Gu h.L.li W.h.li Z.L.Pei J.Gong C.Sun School of Materials Science and Engineering University of Science and Technology of ChinaShenyang 110016China Institute of Metal Research Chinese Academy of SciencesShenyang 110016China

In order to improve the oxidation and wear resistance of blades tip of titanium alloys as well as the sealing performance of the gas turbine engine,a Ni/cBN abrasive coating was prepared on titanium alloys through composite ***,mechanical and tribological properties of the abrasive coating were ***,the effect of the oxidation on the mechanical and tribological properties was also *** results revealed that the abrasive coating underwent slight oxidation within 700℃.Meanwhile,some intermetallic compounds,Ni3Ti,NiTi and NiTi2,were formed at the coating/substrate interface during *** to the pinning effect of cBN particles and the different thermal expansion coefficients of the coating and substrate,the coating/substrate interface was cracked after oxidation at 700℃.Tensile results showed that the presence of coating reduced the strength of the alloy significantly at room temperature,while only marginal variations of the strength of the coated and uncoated specimens at elevated ***,the wear tests indicated that the coating had the excellent cutting ability and wear resistance,which can effectively protect the blades tip of titanium *** the temperature increased,the wear resistance decreased due to the decrease in the mechanical properties of the Ni/cBN coating.

关键词： Abrasive coating Oxidation Mechanical properties Wear Titanium alloy