• 제목/요약/키워드: Materials engineering

검색결과 38,272건 처리시간 0.085초

Modeling the Density and Hardness of AA2024-SiC Nanocomposites

  • Jeon, A-Hyun;Kim, Hong In;Sung, Hyokyung;Reddy, N.S.
    • 한국분말재료학회지
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    • 제26권4호
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    • pp.275-281
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    • 2019
  • An artificial neural network (ANN) model is developed for the analysis and simulation of correlation between flake powder metallurgy parameters and properties of AA2024-SiC nanocomposites. The input parameters of the model are AA 2024 matrix size, ball milling time, and weight percentage of SiC nanoparticles and the output parameters are density and hardness. The model can predict the density and hardness of the unseen test data with a correlation of 0.986 beyond the experimental data. A user interface is designed to predict properties at new instances. We have used the model to simulate the individual as well as the combined influence of parameters on the properties. Moreover, we have analyzed the calculated results from the powder metallurgical point of view. The developed model can be used as a guide for further composite development.

Influence of Reaction Conditions on the Grafting Pattern of 3-Glycidoxypropyl trimethoxysilane on Montmorillonite

  • He, Wentao;Yao, Yong;He, Min;Kai, Zhang;Long, Lijuan;Zhang, Minmin;Qin, Shuhao;Yu, Jie
    • Bulletin of the Korean Chemical Society
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    • 제34권1호
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    • pp.112-116
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    • 2013
  • Surface modification of montmorillonite (MMT) with 3-glycidoxypropyl trimethoxysilane (3GTO) in mild methanol/water mixture has been investigated in detail. The influence of reaction conditions (including silane concentration in feed, reaction time and reaction temperature) on the grafting amount and yield of silane, and further on the grafting pattern of silanes was studied by thermogravimetric analysis, elemental analysis, X-ray diffraction (XRD) and BET. Higher silane concentration, longer reaction time and higher reaction temperature are all benefit to higher grafting amount. When the grafting reaction was performed with 3 mmol/g silane concentration, at $90^{\circ}C$ for 24 h, the grafted amount and yield of silane reached 1.4443 mmol/g and 30%, respectively. Based on the XRD and BET data analysis, a speculation that the grafting pattern of silanes was concentration dependence was proposed.

Electrical and magnetic properties of GaMnN with varying the concentrations of Mn and Mg

  • F.C. Yu;Kim, K.H.;Lee, K.J.;H.S. Kang;Kim, J.A.;Kim, D.J.;K.H. Baek;Kim, H.J.;Y.E. Ihm
    • 한국재료학회:학술대회논문집
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    • 한국재료학회 2003년도 춘계학술발표강연 및 논문개요집
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    • pp.109-109
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    • 2003
  • III- V ferromagnetic semiconductor has attracted great attention as a potential application for spintronics due to a successful demonstration of spin injection from ferromagnetic GaNnAs into semiconductor. GaMnN may be one of the possible candidates for room temperature operation. Samples were grown on sapphire (0001) substrate at $650^{\circ}C$ via molecular beam epitaxy with a single Precursor of (Et$_2$Ga(N$_3$)NH$_2$$CH_3$) and solid source of Mn at different Mn source temperature. The background pressure is low 10$^{-10}$ Torr and the samples growth pressure was 1.4 $\times$ 10$^{-6}$ Torr.

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