Key Laboratory of Advance Materials in Yunnan Province

Kunming, China

Key Laboratory of Advance Materials in Yunnan Province

Kunming, China
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Du J.,Kunming University of Science and Technology | Du J.,Key Laboratory of Advance Materials in Yunnan Province | Du J.,Key Laboratory of Advance Materials of Precious Nonferrous Metals | Gan G.,Kunming University of Science and Technology | And 11 more authors.
Advanced Materials Research | Year: 2012

Preparation of aqueous ceramics slurry with high solid volume and low viscosity is premise and key step of gelcasting, and dispersant play important role in slurry preparation. In this paper, triammonium citrate (TAC) was used as dispersant of PMN-PZT piezoelectric ceramics slurry, the effects of TAC on slurry stability and rheological properties and dispersion mechanism of TAC were investigated by sedimentation test, viscosity, scanning electron microscopy (SEM) and FTIR analysis. The SEM results indicated that TAC could reduce the agglomeration of powder particles and make ceramic particles well-dispersed. FTIR indicated that strong chemical absorption occurred between TAC and PMN-PZT powder, and slurry stability and rheological properties of PMN-PZT slurry were improved through electrostatic interaction of TAC. The effects of TAC on sedimentation volume and viscosity have similar tendency. When TAC content was 7.5vol% and pH of slurry was about10, PMN-PZT slurry suitable for gel-casting could be acquired. © (2012) Trans Tech Publications.


Li L.,Kunming University of Science and Technology | Li L.,Key Laboratory of Advance Materials in Yunnan Province | Du J.,Kunming University of Science and Technology | Du J.,Key Laboratory of Advance Materials in Yunnan Province | And 10 more authors.
Xiyou Jinshu Cailiao Yu Gongcheng/Rare Metal Materials and Engineering | Year: 2015

Ultrafine nickel powder was prepared without dispersant by liquid phase reduction method. The hydrazine hydrate was used as the reductant, the nickel sulfate as the raw material and NaOH was the pH regulator. The influences of the reaction temperature, pH, concentration of Ni2+ ions, mole ratio of N2H4·H2O/Ni2+ on the particle size, the morphology and the dispersion of nickel powder were studied. The samples were characterized by the scanning electron microscope (SEM), X-ray diffraction (XRD), laser particle size analysis etc. The results show that the high purity and spherical nickel powder with face-centered cubic structure can be prepared when the temperature is 80℃, pH is 11, the concentration of Ni2+ ions is 0.5 mol/L, the mole ratio of N2H4·H2O/Ni2+ is 4. The average particle size of nickel powder is about 400 nm. Copyright © 2014, Northwest Institute for Nonferrous Metal Research. Published by Elsevier BV. All rights reserved.


Chen X.-X.,Kunming University of Science and Technology | Chen X.-X.,Key Laboratory of Advance Materials in Yunnan Province | Chen X.-X.,Key Laboratory of Advance Materials of Precious Nonferrous Metals Ministry of Education | Du J.-H.,Kunming University of Science and Technology | And 14 more authors.
Dongbei Daxue Xuebao/Journal of Northeastern University | Year: 2012

Porous alumina ceramic was prepared using sodium doddecyl benzene sulfonate (SDBS) as foaming agent by gel-foaming. The effects of the foaming agent on the porosity, fracture strength and microscopic structure of the porous alumina ceramic were studied. The result shows that when the content of the foaming agent increases, the porosity first increases and then decreases, while the fracture strength decreases. The porous alumina ceramic with 58% porosity, fracture strength up to 35 MPa and uniform aperture can be obtained at foaming agent content of 1 wt%.


Chen X.,Kunming University of Science and Technology | Chen X.,Key laboratory of Advance Materials in Yunnan Province | Chen X.,Key laboratory of Advance Materials of Precious Nonferrous Metals | Du J.,Kunming University of Science and Technology | And 11 more authors.
Advanced Materials Research | Year: 2012

Porous alumina ceramic was prepared using sodium dodecyl benzene sulfonate (SDBS) as foaming agent by the combination method of gel casting and foaming. The effect of solid content on the line shrinkage rate, the porosity, the fracture strength and the microscopic structure of porous aluminum ceramic were studied. The result showed that when solid content increased, the line shrinkage rate of porous alumina ceramic decreased form 20% to 1.2%, the total porosity first increased and then decreased from 43% to 57%, the fracture strength first decreased and then increased from 23MPa to 41MPa. SEM indicated that alumina ceramic had more open pores when solid content was too low, the number of closed pore increased along with solid content rising, when solid content was too high, pore size distribution uniformity decreased. © (2012) Trans Tech Publications.

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