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Influence of Cu content on microstructure and mechanical properties of thixoformed Al-Si-Cu-mg alloys

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Transactions of Nonferrous metals Society of China 2015年第11期25卷 3523-3538页

作者： m.S.SALLEH m.z.om.r Department of mechanical and materials Engineering Faculty of Engineering and Built Environment Universiti Kebangsaan Malaysia Department of manufacturing Process Faculty of Manufacturing Engineering Universiti Teknikal Malaysia Melaka

The effects of Cu content on the microstructure and mechanical properties of thixoformed Al-6Si-xCu-0.3mg(x= 3,4,5and 6,mass fraction,%) alloys were *** samples were thixoformed at 50%liquid content and several of the samples were treated with the T6 heat *** samples were then examined by optical microscopy(om),scanning electron microscopy(SEm),energy dispersive X-ray(EDX) spectroscopy and X-ray diffraction(XrD) analysis,as well as hardness and tensile *** results show that the cooling slope casting and thixoforming process promote the formation of very fine and well distributed intermetallic compounds in the aluminium matrix and the mechanical properties of the alloys increase considerably compared with the permanent mould *** results also reveal that as the Cu content in the alloy increases,the hardness and tensile strength of the thixoformed alloys also *** ultimate tensile strength,yield strength and elongation to fracture of the thixoformed heat-treated Al-6Si-3Cu-0.3mg alloy are 298 mPa,201 mPa and 4.5%,respectively,whereas the values of the thixoformed heat-treated alloy with high Cu content(6%) are 361 mPa,274 mPa and 1.1%,*** fracture of the thixoformed Al-6Si-3Cu-0.3mg alloy shows a dimple rupture,whereas in the alloy that contains the highest Cu content(6%),a cleavage fracture is observed.

关键词： Al-Si-Cu-mg alloy Cu content thixoforming T6 heat treatment mechanical properties

microstructural evolution and mechanical properties of thixoformed A319 alloys containing variable amounts of magnesium

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Transactions of Nonferrous metals Society of China 2016年第8期26卷 2029-2042页

作者： m.S.SALLEH m.z.om.r K.S.ALHAWArI m.N.mOHAmmED m.A.mAD ALI E.mOHAmAD Department of manufacturing Process Faculty of Manufacturing Engineering Universiti Teknikal Malaysia Melaka Department of mechanical and materials Engineering Faculty of Engineering and Built EnvironmentUniversiti Kebangsaan Malaysia Department of Engineering and Technology Faculty of Information Sciences and EngineeringManagement and Science University

The effects of mg content on the microstructure and tensile properties of thixoformed A319 alloys were studied. The samples were thixoformed at 50% liquid content and some of the thixoformed samples were subjected to the T6 heat treatment. The samples were then examined by optical microscopy (om), scanning electron microscopy (SEm), energy dispersive X-ray (EDX) spectroscopy and X-ray diffraction (XrD) analysis as well as tensile tests. The results showed that magnesium was able to refine the eutectic silicon in the samples. It was also observed that a compact Al9Femg3Si5 phase was formed when the magnesium content was 1.0% and 1.5%. The results also revealed that as the magnesium content in the alloy increases, the tensile strengths of the thixoformed alloys also increase. The ultimate tensile strength, yield strength and elongation to fracture of the thixoformed A319 heat treated alloy were 298 mPa, 201 mPa and 4.5%, respectively, whereas the values of the thixoformed heat treated alloy with 1.5% mg content were 325 mPa, 251 mPa and 1.4%, respectively. Thixoformed A319 alloy showed a dimple fracture behaviour, while thixoformed A319 alloys with 1.5% mg showed a mixed mode fracture behaviour, where dimple and cleavage ruptures were seen on the fracture surface of the samples.

关键词： aluminium alloy thixoforming T6 heat treatment mechanical properties

Strength Developing in Clay-Andesite Brick

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materials Sciences and Applications 2016年第8期7卷 403-420页

作者： Víctor Julio García Alonso r. zúñiga-Suárez Carmen omaira márquez Juan G. Pérez Francisco Fernández-martínez Francisco Hernández-Olivares Universidad Nacional de Chimborazo Riobamba Ecuador Universidad Técnica Particular de Loja Loja Ecuador Universidad de Los Andes Mérida Venezuela Universidad Politécnica de madrid Madrid Espana

The objective of this work was to develop a more and better understanding of the strength developing in clay-andesite fired brick. The purpose was to improve the quality of the clay bricks that are handmade in the southern region of Ecuador to make them suitable for more widespread use in the local construction industry. To achieve our goal, we first physically, chemically, and mechanically characterized the “clayey” and “sandy” materials used in the fabrication of handmade bricks in the region. Second, the optimal mixture (om): the optimal proportion between the amounts of “clayey” and “sandy” material was sought. Third, clay bricks were prepared using the om, baked at 950°C, and characterized. In addition, bricks produced by regional artisans were characterized, and the results were compared with the results obtained for the bricks prepared using the om. Our data reveal that the optimal mixture is 50% “clayey” material and 50% “sandy” material and that with this mixture, an average improvement in brick quality of 300% can be achieved;thus, the use of the om makes it possible to expand the use of these bricks in the local construction industry and enables an environmentally friendly production process by reducing the intensive exploitation of regional clay deposits. This improvement is achieved by virtue of the anorthite enrichment that occurs in the solid solution, which results from the evolution of andesine. The anorthite contributes to the formation of a stronger matrix among the different grains of the material. Conditions are favorable for this enrichment process to occur when “sandy” materials with high contents of andesite, which is common in Ecuadorian soils, are used.

关键词： Anorthite Andesine Andesite Component Fired Bricks Brazilian Test

ComPOSITION EFFECT ON DrY SLIDING WEAr BEHAVIOrS OF Ti-B-N THIN FILmS

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Acta metallurgica Sinica(English Letters) 2005年第3期18卷 300-306页

作者： P.Sit Y.H.Lu H.Chen z.F.zhou Y.G.Shen K.Y.Li DepartmentofPhysicsandmaterialsScience CityUniversityofHongKongKowloonHongKongChina DepartmentofPhysicsandmaterialsScience CityUniversityofHongKongKowloonHongKongChina／／DepartmentofManufacturingEngineeringg：EngineeringManagementCityUniversityofHongKongKowloonHongKongChina DepartmentofmanufacturingEngineering＆Engineeringmanagement CityUniversityofHongKongKowloonHongKongChina

Friction and sliding wear behaviour of Ti-B-N coatings against AISI440C steel ba ll and WC-6wt%Co ball were studied by using pin-on-disk tribometer along with mi crostructure characterization using optical microscopy (om), scanning electron m icroscopy (SEm) and X-ray photoelectron spectroscopy (XPS). It is shown that the wear resistance of film depended on the wear mechanism. In the case of AISI440C steel, adhesive wear were pre-dominant and the wear rate increased sharply to a maximum when N content reach ~38at.%. This might be related to the change of fi lm microstructure and phase configuration, so the least adhesive transfer of tri bo-film was observed. If WC-6wt%Co ball was used, less deformation wear debris w as observed, this was responsible for the rise of wear rate. Despite of differen t wear modes, friction coefficients in both cases were found to depend mainly on the formation and the amount of h-BN phase. Elemental analysis by energy disper sive spectroscopy (EDS) and X-ray photoelectron spectroscopy (XPS) revealed that oxygen participated in the wear behavior by reacting with films to form the deb ris com.rised of various types of Ti oxide including TiO, TiO2 and Ti2O3 , which increased wear resistance.

关键词： dry sliding wear friction coefficient oxidation Ti-B-N wear

Folding model Analysis of Elastic Scattering of 11B from Light,medium,and Heavy Nuclei

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Communications in Theoretical Physics 2016年第11期65卷 531-540页

作者： m.Aygun Department of Physics Bitlis Eren UniversityBitlisTurkey

The elastic scattering angular distributions of z113 projectile on light, medium, and heavy target nuclei including 7Li, 9Be, 12C, 16O, 24,25,26mg, 27Al, 28Si, 40Ca, 58Ni, 59Co, 60Ni, 197Au, 208Pb, and 209Bi have been analyzed at various incident energies. The theoretical results have been obtained by using two different nuclear potentials within the framework of the optical model （om）. Firstly, the double folding potential for real part and the Wood-Saxon （WS） potential for imaginary part have been applied. Secondly, the calculations with double folding potential for both real and imaginary part have been performed and compared with the experimental data. It has been seen that the results are in very good agreement with the experimental data. Also, the volume integrals and cross-sections for each reaction have been obtained. Finally, a new and simple formula for the imaginary potential depth has been derived to clarify the nuclear interactions of 11B nucleus at low energy reactions.

关键词： optical model elastic scattering

Обэор Харбинского Политехнического Института эа 10 лет.

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哈尔滨工业大学学报 1959年第3期 13-16页

作者： Дчрекмор Харбчнскоzо Полчмехнчческоzо Инсмчмума ЛИ ЧАН Дчрекмор Харбчнскоzо Полчмехнчческоzо Инсмчмума ЛИ ЧАН

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关键词： Ho Te Be Ba HO Ta 只只

Square-root parametrization of dark energy in f(Q)cosmology

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Communications in Theoretical Physics 2023年第12期75卷 105-114页

作者： m Koussour N myrzakulov Alnadhief H A Alfedeel E I Hassan D Sofuoğlu Safa m mirgani Quantum Physics and magnetism Team LPMCFaculty of Science Ben M'sikCasablanca Hassan II University L.N.Gumilyov Eurasian National University ratbay myrzakulov Eurasian International Centre for Theoretical Physics Department of mathematics and Statistics Imam Mohammad Ibn Saud Islamic University(IMSIU) Department of Physics Faculty of ScienceUniversity of Khartoum Centre for Space research North-West University Department of Physics Istanbul University Vezneciler 34134

This paper is a parametrization of the equation of state(Eo S)parameter of dark energy(DE),which is parameterized using square-root(Sr)form i.e.ω_(Sr)=ω_(0)+ω_(1)z/√z^(2)+1,where ω_(0)and ω_(1) are free *** parametrization is examined in the context of the recently suggested f(Q)gravity theory as an alternative to general relativity(Gr),in which gravitational effects are attributed to the non-metricity scalar Q with the functional form f(Q)=Q+αQ^(n),whereαand n are arbitrary *** derive observational constraints on model parameters using the Hubble dataset with 31 data points and the Supernovae(SNe)dataset from the Pantheon samples compilation dataset with 1048 data *** the current model,the evolution of the deceleration parameter,density parameter,EoS for DE,and om(z)diagnostic have all been *** has been shown that the deceleration parameter favors the current accelerated expansion *** has also been shown that the EoS parameter for DE has a quintessence nature at this time.

关键词： cosmology dark energy f(Q)gravity EoS parameter

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小波变换用于示波计时电位法中重叠峰解析

西北大学学报：自然科学版 1999年第4期29卷 313-316页

作者：张红权郑建斌仲红波潘忠孝张懋森西北大学电分析化学研究所陕西西安710069 中国科学技术大学应用化学系安徽合肥230026

基于小波变换的分频及时移不变性，将小波变换用于示波计时电位法中重叠峰解析的研究。探讨了极化电流大小、频率和示波信号中噪音、分解次数等因素对小波变换结果的影响。实验结果表明：小波变换能从含有噪音和背景的信号中提取有用信... 详细信息

基于小波变换的分频及时移不变性，将小波变换用于示波计时电位法中重叠峰解析的研究。探讨了极化电流大小、频率和示波信号中噪音、分解次数等因素对小波变换结果的影响。实验结果表明：小波变换能从含有噪音和背景的信号中提取有用信息，使信号中重叠峰获得了较好的分离，可用于多组分的定量分析。

关键词：示波分析小波变换重叠峰解析示波计时电位法

Pm2.5 and Pm10-2.5 chemical composition and source apportionment near a Hong Kong roadway

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PM2.5 and PM10-2.5 chemical composition and source apportion...