Guizhou Key Laboratory for Microstructure and Strength of Materials

Guiyang, China

Guizhou Key Laboratory for Microstructure and Strength of Materials

Guiyang, China
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Zhang L.Y.,Guizhou University | Liu Q.B.,Guizhou University | Liu Q.B.,Guizhou Key Laboratory for Microstructure and Strength of Materials | Jiang P.Z.,Guizhou University | Zhang Z.,Guizhou University
Applied Mechanics and Materials | Year: 2013

To improve bonding strength between Ti alloy and bioceramic coating and to eliminate thermal stress during laser cladding, gradient bioceramic coating materials is designed. The bioceramic coating is fabricated by wide band laser cladding technique. And the effect of adding single and multiple rare earth oxide on microstructure is investigated. The samples are soaked with SBF for 14 days, the experimental results indicate that when the content of single rare earth oxide is 0.6wt. %Y2O3, a large number of bioactivity phase and chrysanthemum shape microstructure can be observed. When the content of single rare earth oxide is 0.2wt. %Sm2O3, a lot of bioactivity phase and coral reef shape microstructure can be observed. When the content of multiple rare earth oxide is 0.3wt. %Sm2O3 and 0.4wt.%Y2O3, a large amount of bioactivity phase and more homogeneous and dense spherical particles can be observed on coating, which demonstrates the microstructure is of better bioactivity. © (2013) Trans Tech Publications Switzerland.


Wang Z.,Guizhou University | Liu Q.,Guizhou University | Liu Q.,Guizhou Key Laboratory for Microstructure and Strength of Materials | Xiao M.,Guizhou University | Yang B.,University of Sichuan
Zhongguo Jiguang/Chinese Journal of Lasers | Year: 2011

To decrease the thermal stress and raise the bonding strength between substrate and bioceramic coating during laser cladding, a rare earth active bioceramic gradient coating is designed. The rare earth active gradient bioceramic coating with HA and β-TCP on TC4 allloy is prepared by using wide-band laser cladding technique. The microstructure, bioactivity and corrosion resistance of bioceramic coating are analyzed by scanning electron microscope (SEM), X-ray diffraction (XRD), simulated body fluid (SBF), and electrochemical analyzer. The experimental results show that the bioactive rare earth gradient coating which has excellent chemical metallurgy bonding at the interface consists of substrate, alloying layer and bioceramic coating. Nd2O3 plays an important role in synthesizing HA and β-TCP during wide-band laser cladding. When the mass fraction of Nd2O3 is up to 0.6%, the amount of HA+β-TCP catalyzed during wide-band laser cladding becomes the largest. When the mass fraction of Nd2O3 is 0.4%-0.6%, the corrosion resistance of bioceramic coating is the best one, and the amount of HA deposited on coating becomes the biggest, showing the best bioactivity.


Zhang L.Y.,Guizhou University | Liu Q.B.,Guizhou University | Liu Q.B.,Guizhou Key Laboratory for Microstructure and Strength of Materials
Advanced Materials Research | Year: 2013

To improve bonding strength between titanium alloy and coating and to eliminate thermal stress during laser cladding, a gradient coating materials is designed. And the gradient coating with different contents of multiple rare earth deoxide was produced by wide band laser cladding technique. The experimental results indicate that when addition of Sm2O3 is fixed to 0.3wt.%, as addition of Y2O3 increases, the microstructure of bioceramic is different. When addition of Y2O3 reaches 0.4wt.%, the amount of Ca-P based bioactive phases such as HA, α-TCP as well as β-TCP becomes biggest. After soaking the coating with 0.3wt.% Sm2O3 and 0.4wt.% Y2O3 in SBF for 14 days, a large amount of Ca-P white spherical particles can be observed on coating, which demonstrates the bioceramic coating is of best bioactivity. © (2013) Trans Tech Publications, Switzerland.


Feng L.,Guizhou University | Liu Q.-B.,Guizhou University | Liu Q.-B.,Guizhou Key Laboratory for Microstructure and Strength of Materials
Advanced Materials Research | Year: 2012

To improve the service performance of roller. The surface of roller was alloyed by a 5kW CO 2 laser. The microstructure, hardness and wear resistance were investigated by means of OM, XRD, Micro-hardness Testing Machine and MMS-2A screen display friction tester. The experimental results indicate that excellent metallurgical bonding is obtained between alloying layer and substrate, the main microstructure of laser alloying coating is composed of phases such as γ-Fe, Fe(Ni,Cr), (Fe,Cr) 7C 3, MoC, Fe 2MoC, WC and SiC etc. The strengthening mode is particle-reinforced mechanism. The corrosion resistance of connection zone is better than that of alloying zone. The average of microhardness value is as high as 718 HV, which is more two times than that of substrate, and the average of wear resistance value of alloying layer is approximately three times larger than that of substrate. © (2012) Trans Tech Publications, Switzerland.


Liu D.,Guizhou University | Liu D.,Guizhou Key Laboratory for Microstructure and Strength of Materials | Liu Q.-B.,Guizhou University | Liu Q.-B.,Guizhou Key Laboratory for Microstructure and Strength of Materials
Hongwai yu Jiguang Gongcheng/Infrared and Laser Engineering | Year: 2010

In order to eliminate thermal stress and raise bonding strength between substrate and coating during laser cladding, bioceramic gradient coating was designed. The bioceramic gradient coating with HA and β-TCP on surface of ti-allloy was prepared by using wide-band laser cladding technique. The surface morphologies and structural were analyzed by OM, SEM and XRD. And the bioceramic coating was immersed in SBF to examine its bioactivity. Results show that the bioceramic gradient coatings have excellent chemical metallurgy bonding on the interface, and the coatings consist of substrate, alloy layer and bioceramic coating. La 2O 3 plays an important role in inducing to synthesize HA and β-TCP during laser cladding . When the content of La 2O 3 reaches to 0.6 wt.%, the amount of synthesizing HA and β-TCP is the most. Bioactivity of bioceramic coating is dependent on the amount of HA + β-TCP catalyzed by different La 2O 3 contents. The largest amount of apatite formed on the surface of coating is complied with 0.6 wt.% La 2O 3, and the amount of apatite of coating soaked in SBF after 14 days is obviously more than that of 7 days.


Jiang H.,Guizhou University | Liu Q.,Guizhou University | Liu Q.,Guizhou Key Laboratory for Microstructure and Strength of Materials | Zhang L.,Guizhou University | Zhu Y.,Guizhou University
Xiyou Jinshu/Chinese Journal of Rare Metals | Year: 2016

To explore the effect of rare earth on morphology and degradability of bioceramic coating, the gradient calcium phosphate ceramic coating containing hydroxyapatite (HA) and β-tricalcium phosphate (β-TCP) was prepared on Ti alloy surface by laser-cladded technology, gradient composition design and gradient power sintering. A series of experimental methods including X-ray diffraction (XRD), scanning electron microscope (SEM) and inductively coupled plasma atomic emission spectrometry (ICP-AES) were used to measure the coating performances. The results indicated that the rare earth La2O3 could catalyze to synthesize HA and β-TCP, reduce the cracking sensitivity of coatings in simulated body fluid (SBF) and refine the grain size of bone-like apatite. When the addition of rare earth was 0.4%, the diffraction peak of HA and β-TCP achieved the highest. The same size and uniform distribution of bone-like apatite appeared in the coating surface without cracks after soaking in SBF for 14 d. The degradation rate of coating soaked in SBF for 28 d was 0.2126%. The Ca2+ and La3+ concentration in SBF changed with the soaking time. The Ca2+ concentration was of volatility and dynamic equilibrium. And the concentration decreased gradually. It indicated that the amount of Ca2+ deposited from the solution onto the surface was more than that degraded into solution. While the concentration of La3+ increased with the soaking time. The La3+ concentration and soaking time had a significant linear relationship when using the method of linear fitting by logarithmic on the two parameters. And the empirical formula about La3+ concentration, soaking time and surface area of coating was derived. © Editorial Office of Chinese Journal of Rare Metals. All right reserved.


Lu P.,Guizhou University | Lei Y.,Guizhou University | Lu S.,Guizhou University | Wang Q.,Guizhou University | Liu Q.,Guizhou Key Laboratory for Microstructure and Strength of Materials
Analytica Chimica Acta | Year: 2015

Glucose detection plays very important roles in diagnostics and management of diabetes. The search for novel catalytic materials with appropriate architectures is the key step in the fabrication of highly sensitive glucose sensors. In this work, α-Ni(OH)2 roselike structures (Ni(OH)2-RS) assembled from nanosheet building blocks were successfully synthesized by a hydrothermal method through the hydrolysis of nickel chloride in the mixed solvents of water and ethanol with the assistance of polyethylene glycol (PEG). The structure and morphology of the roselike α-Ni(OH)2 were characterized by transmission electron microscopy (TEM), field emission scanning electron microscopy (FE-SEM), X-ray photoelectron spectroscopy (XPS), X-ray powder diffraction (XRD) and N2 adsorption-desorption isotherm measurement. TEM and FE-SEM images showed that the synthesized Ni(OH)2 was roselike and the size of the leaf-shaped nanosheet was about 5nm in thickness, which leads to larger active surface areas and faster electron transfer for the detection of glucose. Compared with the bare GCE and bulk Ni(OH)2/GCE, the Ni(OH)2-RS/GCE had higher catalytic activity toward the oxidation of glucose. Under the optimal conditions, the Ni(OH)2-RS/GCE offers a variety of merits, such as a wide linear response window for glucose concentrations ranging from 0.87μM to 10.53mM, short response time (3s), a lower detection limit of 0.08μM (S/N=3), as well as long term stability and repeatability. © 2015 Elsevier B.V..


Liu Q.,Guizhou University | Liu Q.,Guizhou Key Laboratory for Microstructure and Strength of Materials | Yuan M.,Guizhou University
Advanced Materials Research | Year: 2012

To improve the room resistivity, 96MgAl 2O 4-2SiO 2-2TiO 2 honeycomb ceramic doped with different Y 2O 3 contents was fabricated by technique of raditional solid phase sintering. The microstructure and room resistivity of the samples were nvestigated by SEM and portable pH/Cond 3400i resistivity tester. The results show that as the amount of the Y 2O 3 increases, room resistivity of the samples decreases gradually. When Y 2O 3 content is up to 0.06mol%, the resistivity becomes minimum with 5.5×10 1Ω·m. When Y 2O 3 content is up to 0.10mol%, the resistivity conversely increases. © (2012) Trans Tech Publications, Switzerland.


Xia C.,Guizhou University | Liu Q.,Guizhou University | Liu Q.,Guizhou Key Laboratory for Microstructure and Strength of Materials | He M.,Guizhou University
Advanced Materials Research | Year: 2012

To obtain ZnO varistors with high voltage gradient, ZnO varistors were fabricated by traditional ceramic sintering technique, the effect of different sintering temperature (1135∼1155 °C) on electrical properties of ZnO varistors were investigated. The experimental results show that with increasement of sintering temperature, the grain size of ZnO varistor ceramic becomes bigger, the voltage gradient of varistor decreases and the density is improved. When the sintering temperature is at 1135 °C, the voltage gradient of varistor is up to 329V/mm, the leakage current is 8μA and the density is 96.4%. When the sintering temperature is at 1140 °C, the voltage gradient of varistor is 301V/mm, the leakage current is 4μA and the density is 96.6%. Compared the results at 1135 °C with 1140 °C, it is found that the comprehensive electrical properties of ZnO varistors reach maximum at 1140 °C. © (2012) Trans Tech Publications, Switzerland.


PubMed | Guizhou University and Guizhou Key Laboratory for Microstructure and Strength of Materials
Type: | Journal: Analytica chimica acta | Year: 2015

Glucose detection plays very important roles in diagnostics and management of diabetes. The search for novel catalytic materials with appropriate architectures is the key step in the fabrication of highly sensitive glucose sensors. In this work, -Ni(OH)2 roselike structures (Ni(OH)2-RS) assembled from nanosheet building blocks were successfully synthesized by a hydrothermal method through the hydrolysis of nickel chloride in the mixed solvents of water and ethanol with the assistance of polyethylene glycol (PEG). The structure and morphology of the roselike -Ni(OH)2 were characterized by transmission electron microscopy (TEM), field emission scanning electron microscopy (FE-SEM), X-ray photoelectron spectroscopy (XPS), X-ray powder diffraction (XRD) and N2 adsorption-desorption isotherm measurement. TEM and FE-SEM images showed that the synthesized Ni(OH)2 was roselike and the size of the leaf-shaped nanosheet was about 5 nm in thickness, which leads to larger active surface areas and faster electron transfer for the detection of glucose. Compared with the bare GCE and bulk Ni(OH)2/GCE, the Ni(OH)2-RS/GCE had higher catalytic activity toward the oxidation of glucose. Under the optimal conditions, the Ni(OH)2-RS/GCE offers a variety of merits, such as a wide linear response window for glucose concentrations ranging from 0.87 M to 10.53 mM, short response time (3s), a lower detection limit of 0.08 M (S/N=3), as well as long term stability and repeatability.

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