A simple method of acid etching and surface passivation was developed for fabricating the super-hydrophobic surface on polycrystalline aluminum alloy. After the chemical etched surface was fabricated with the stearic-acid, the aluminum alloy surface exhibits a super-hydrophobic property with water contact angle of 151 degrees and contact angle hysteresis of 8 degrees. The surface morphology was inspected with scanning electron microscope, and it was found that the surface is configured in a labyrinthic porous structure with plateaus and caves of micro-nanostructure. The air cushion was formed in the caves between the surfaces. This micro-nano hierarchical structure plays an important role in the formation of the super-hydrophobicity. The super-hydrophobic phenomenon of the prepared surface was analyzed with Cassie theory, and the result shows that only about 16% of the water contact surface are contacted with the metal substrate and the rest 84% is contacted with the air cushion. The experimental results showed that aluminum of super-hydrophobic surface can be prepared by this simple method, the optimum process conditions found are after grinding, ethanol soaking, acetic acid soaking sixty hours, immersing in the 0.1mol/L potassium permanganate three hours after soaking and finally immersion in 1% stearic-acid for 30 minutes. (C) 2011 Published by Elsevier Ltd. Selection and/or peer-review under responsibility of Chinese Materials Research Society
MnZn ferrite nanoscale particles were synthesized by hydrothermal method. The effects of amount of addition La3+ on the products were discussed. The product was characterized by X-ray diffraction (XRD) and transmission electron microscope (TEM). The results show that the sample with 0.2% La3+(mass fraction) or without La3+ has only spinel phase, but the sample with mass fraction of La3+ exceeding 0.4% posses second phase besides the spinel one; and the nano-MnZn ferrites change from cube to hexagon when the mass fractions of La3+ is up to 1.2%. TEM image of the sample with 1.2% La3+ indicates that the homogeneous hexagonal crystal is obtained and the particles are larger than those of undoped; the addition of La3+ has great influence on the crystallization of hydrothermal process and can change the shape of particles and improve their growth. The saturation magnetization of the sample with 1.2% La3+ (2.64 A·m2·kg-1) is lower than that of undoped (17.54 A·m2·kg-1) and it behaves superparamagnetically.
Chemical Engineering Journal,2018年335:301-308 ISSN：1385-8947
[Liang, Shuquan; Pan, Anqiang; Cao, Xinxin; Li, Jiwei; Yang, Hulin; Zhao, Yilin] School of Material Science and Engineering, Central South University, Changsha, Hunan, 410083, China;[Cao, Guozhong] Department of Materials Science &, Engineering, University of Washington, Seattle, WA, 98195, United States
Transactions of Nonferrous Metals Society of China,2002年12(6):1020-1023 ISSN：1003-6326
Cent S Univ, Natl Key Lab Powder Met, Changsha 410083, Peoples R China.;Cent S Univ, Sch Mat Sci & Engn, Changsha 410083, Peoples R China.;[Liang Shuquan; Huang Baiyun] National Key Laboratory for Powder Metallurgy, Central South University,Changsha 410083, China;[Liang Shuquan] School of Materials Science and Engineering, Central South University,Changsha 410083, China;[Li Weizhou] 中南大学
suspension system;rheology;Einsteins viscose law
The viscose models for powder suspension system was reviewed and analysed. It is found that by introducing modification function f(φ) in the differential form of classical Einsteins viscosity law, all of viscose models can be unified if f(φ) takes suitable form . Some rational forms of the function f(φ) were discussed according to functional approximation method, and a new rheological model contained two undetermined parameters was consequently developed, more suitable for high particle concentration dispersing system. The experimental results show that this new model is of better consistence.
Transactions of Nonferrous Metals Society of China,2004年14(4):762-768 ISSN：1003-6326
[梁叔全] Cent S Univ, Sch Mat Sci & Engn, Changsha 410083, Peoples R China.;Cent S Univ, State Key Lab Powder Met, Changsha 410083, Peoples R China.
[Liang, SQ] Cent S Univ, Sch Mat Sci & Engn, Changsha 410083, Peoples R China.
binder;chemistry;powder injection molding
The polymer binder selection is one of the very important aspects for the powder injection molding.However, even nowadays the binder selection is still mainly performed by try and error method. Six commercial or intensive studied binder formulas were analyzed according to state diagram and chemical characteristics of ingredients in each binder formula. In addition, the interactions between the binder components and additives were also taken into account. Based on the analysis, the optimum binder formula was selected and some selection criterions were put forward for the binder and additives.
Liang Shuquan（梁叔全）;Tang Yan*;Zhang Yong;Zhong Jie
[Liang Shuquan; Tang Yan; Zhang Yong; Zhong Jie] Cent S Univ, Sch Mat Sci & Engn, Changsha 410083, Hunan, Peoples R China.
2nd International Conference on Multi-Functional Materials and Structures
OCT 09-12, 2009
Qingdao, PEOPLES R CHINA
[Liang Shuquan;Tang Yan;Zhang Yong;Zhong Jie] Cent S Univ, Sch Mat Sci & Engn, Changsha 410083, Hunan, Peoples R China.
Advanced Materials Research
metal powder injection molding;carbon nanotube;feedstock;rheology properties
Carbon nanotubes/ iron compound powder was prepared by high energy ball milling after purified and activated the CNTs. Then, the compound powder and paraffin wax based-binders were mixed to prepare feedstock and the rheological behavior was evaluated by SEM, rheometer and infrared spectrum analysis. By changing the CNTs content and powder loading, the viscosity, shear rate sensitive factor and viscos-activation energy were calculated. 0.2wt% of CNTs, the feedstock can disperse in the binders uniformly without the flowability affecting. Meanwhile, adding proper ratio of CNTs can increase the powder loading of MIM feedstock about 10%, which can optimize the following process conditions and the properties of MIM product.