国强 luo | Wuhan University of Technology (original) (raw)

Papers by 国强 luo

2016 17th International Conference on Electronic Packaging Technology (ICEPT), 2016

Materials Science and Engineering a, 2013

Journal of Wuhan University of Technology-Mater. Sci. Ed., 2011

Various parameters in spark plasma sintering(SPS), such as sintering temperature, holding time, h... more Various parameters in spark plasma sintering(SPS), such as sintering temperature, holding time, heating rate, and pressure, were adopted to investigate their effects on the densification of pure SnO 2 power. The obtained experimental data show that the SPS process enhances densification. The high-density undoped SnO 2 ceramics (96.6% of theoretical) was obtained at much lower temperature (1000), ℃ within a much shorter time, compared to the conventional sintering process. The high-density undoped SnO 2 ceramics (96.6% of theoretical) were obtained by SPS, under the condition of temperature:1000 ℃, pressure: 40 MPa, heating-rate: 200 ℃/min, and holding time: 3 min

Proceedings of the 2nd International Conference on Civil, Materials and Environmental Sciences, 2015

The superhydrophobic silica coating has a great performance of self-cleaning which can be applied... more The superhydrophobic silica coating has a great performance of self-cleaning which can be applied in the field of energy saving, anti-icing, drag reduction, etc. In this paper, Trimethyltrimethoxysilane (MTMS) /Trimethylchlorosilan (TMCS) superhydrophobic silica coating with two-layer structure was dip-coated. Atomic force microscope (AFM) images show that the surface morphology of MTMS/TMCS silica coating was in micro and nano level, and Sa value was 231nm, which could achieve good superhydrophobic performance. MTMS/TMCS silica coating has better superhydrophobic performance than MTMS silica coating. The largest contact angle (CA) of MTMS/TMCS silica coating could reach 155.2°, the sliding angle was less than 10°. The MTMS/TMCS silica coating also has good performance of transmittance in the range of visible light and self-cleaning, the transmittance rate could reach more than 95%. All good performances of the MTMS/TMCS silica coating are from its micro and nano surface structure. Modification of TMCS solution would generate a more stable functional group.

ABSTRACT Using high aluminum refractory material as substrate at 1 400 °C, we studied the connect... more ABSTRACT Using high aluminum refractory material as substrate at 1 400 °C, we studied the connections between several oxides such as Fe2O3, MnO2, CuO, and the formation of defects such as coating crack, exfoliation, blistering, erosion, and fading away appeared in the application of high temperature infrared radiation coating. Analyses showed that thermal stress formed during the heating process due to the thermal expansion coefficient differential between the coating and the substrate, and volume effect caused by the crystal transferred when the temperature changed, which resulted in the coating crack and exfoliation. The gas produced by the reactions between components and binder or the components themselves during the heating process caused the coating blistering. The EMPA and XRD analyses show that oxides with low melting point in the penetrating area of the substrate may form eutectic with low melting point and produced thermal defects, which leads to the erosion by penetrating to the substrate. The valent changes of Fe2O3 and MnO2 during the heating process cause the volatilization of the oxides or the pulverization of the coatings, resulting in the coating fades away easily at high temperature for a long time.

Science China Physics, Mechanics and Astronomy, 2011

Two types of Mg-Cu composition system graded density impactors used for complex loading (shock lo... more Two types of Mg-Cu composition system graded density impactors used for complex loading (shock loading and quasi-isentropic compression) are designed by the elastic-plastic hydrodynamic method in this paper. Mixtures of metal powders in the Mg-Cu system are cast into a series of 17 and 25 uniform compositions ranging from 100% Mg to 100% Cu. The graded density impactors are launched to the stationary 10 m aluminum film and 12 mm LiF window targets by a two-stage light-gas gun in the National Key Laboratory for Shock Wave and Detonation Physics Research, Institute of Fluid Physics, CAEP, and the resulting wave profiles are measured with the DISAR system. Hydrodynamic simulation results are perfectly consistent with the experiments. Our work in this paper will set up a foundation for further research of controllable loading/releasing routes and rate experiments in the future.

Journal of Materials Science, 2014

ABSTRACT In this study, we conducted the diffusion bonding of Mg and Al alloys using a 30-μm-thic... more ABSTRACT In this study, we conducted the diffusion bonding of Mg and Al alloys using a 30-μm-thick pure silver foil interlayer at median temperatures between 390 and 490 °C. We obtained a multilayered structure across the Mg–Ag–Al joint: Mg/Mg(ss, Ag)/Mg3Ag/MgAg/Ag/Ag(ss, Al)/Ag2Al/Al. The silver diffusion barrier prevented the formation of brittle intermetallics between Mg and Al. Intermetallics identified at the joint interface include the more ductile types between Mg and Ag, ε-Mg3Ag and β′-MgAg, and Ag and Al, δ-Ag2Al. As the bonding temperature increased, Ag2Al, followed by MgAg, favored the growth of Mg3Ag IMC layer. The shear strength of the joints increased with the rising bonding temperature to a maximum value of 11.8 MPa at 470 °C. Fracture failure in the joints mainly occurred in the Ag2Al layer. The formation mechanism for interfacial layers in the joints is believed to consist of four stages: (1) solid-solution formation, (2) Mg–Ag IMC formation, (3) Ag–Al IMC formation, and (4) growth of Mg–Ag and Ag–Al IMCs.

Materials Science Forum, 2005

In the present paper, the relationship between characteristic wave impedance and compositions was... more In the present paper, the relationship between characteristic wave impedance and compositions was mainly investigated in order to find a suitable theoretical model for predicting the impedance value of Ti-Mo system composites and FGM. At first, dense Ti-Mo composites with different weight fractions of Mo were prepared. Then the transverse and longitudinal wave velocities of the samples were measured and the characteristic wave impedance values were obtained. A mixture model was adopted to estimate the characteristic wave impedance value of Ti-Mo composites. Comparisons between the estimated and experimental results demonstrated that the suggested model was sufficiently accurate to predict the characteristic wave impedance value of Ti-Mo system composites and FGM.

Scientia Sinica Physica, Mechanica & Astronomica, 2014

Materials Letters, 2012

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Materials Letters, 2012

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Journal of Physics: Conference Series, 2013

ABSTRACT In this paper, the particle co-sedimentation process is analyzed by discrete element ana... more ABSTRACT In this paper, the particle co-sedimentation process is analyzed by discrete element analysis. The formation of deposits of continuous functionally graded materials derived from the particle co-sedimentation method is simulated. The porosity of the deposit is calculated and the variation of the porosity along the deposition direction is obtained. From the simulation, the method to increase the deposit density is firstly generated, which is helpful for preparation of functionally graded materials by particle co-sedimentation method.

Journal of Physics: Conference Series, 2013

ABSTRACT Mg-Al bonded composite materials expand Mg and Al alloys' applications by combin... more ABSTRACT Mg-Al bonded composite materials expand Mg and Al alloys' applications by combining their unique performances together. However, the formation of Mg-Al intermetallic compounds in interface zone of Mg/Al directly-bonded joint seriously obstructs its further development. To solve this problem, Mg-Ag-Al multilayer composite materials have been successfully prepared by diffusion bonding technology. The effect of key process parameter (bonding temperature) on microstructure of this material has been mainly investigated. The results show that Mg and Al were well bonded by using silver interlayer when the bonding temperature exceeded 370°C. But Mg17Al12 and Mg2Al3 compounds were formed in the interface zone at temperatures higher than 420°C. By means of controlling the bonding temperature (380 °C-420 °C), silver interlayer effectively restrained the generation of Mg-Al intermetallic compounds, and Mg-Ag intermetallic compounds (Mg3Ag, MgAg) were formed in the interface zone instead.

Journal of Alloys and Compounds, 2012

Journal of Alloys and Compounds, 2013

Diffusion bonded Mg-Al joints with and without an interlayer were produced. An Ni foil interlayer... more Diffusion bonded Mg-Al joints with and without an interlayer were produced. An Ni foil interlayer eliminated the formation of Mg-Al intermetallic compounds, while addition of an Al thin film to the interlayer improved the properties of the Mg-Ni intermetallic compounds. The shear strength of the joints was improved by the addition of the Ni foil and Al thin film interlayer.

IOP Conference Series: Materials Science and Engineering, 2011

Dense SnO2-based electrode ceramics have extensive application prospect in glass electric-melting... more Dense SnO2-based electrode ceramics have extensive application prospect in glass electric-melting industry due to the excellent electrically-conductive and chemical property in high temperatures and oxidation environment. In this paper, dense SnO2-based electrode ceramics doped with MnO2 and Sb2O3 were prepared by pressureless sintering method and the corrosion rate in soda-lime glass liquid as well as the microstructure evolution was mainly

Fire and Materials, 2012

Compact silicone/alumina composite was obtained by highly filling aluminum oxides and hydroxides ... more Compact silicone/alumina composite was obtained by highly filling aluminum oxides and hydroxides in silicone resin. The flexural strength and dimensional change of the silicone/alumina composite after being fired has have been studied. It presented a special fire resistance, which could well coordinate the contradiction between the mechanical strength retention and the dimensional stability of silicone-based composite in case of catching fire. Thermogravimetric analysis, scanning electron microscopy, X-ray diffraction, transmission electron microscopy, and electron dispersion spectroscopy were applied to systematically explore the process of the in-suit organic-to-inorganic transformation. A possible mechanism was proposed to illustrate the phenomenon of the high strength retention and dimensional stability of silicone/alumina composite under fire.

2016 17th International Conference on Electronic Packaging Technology (ICEPT), 2016

Materials Science and Engineering a, 2013

Journal of Wuhan University of Technology-Mater. Sci. Ed., 2011

Various parameters in spark plasma sintering(SPS), such as sintering temperature, holding time, h... more Various parameters in spark plasma sintering(SPS), such as sintering temperature, holding time, heating rate, and pressure, were adopted to investigate their effects on the densification of pure SnO 2 power. The obtained experimental data show that the SPS process enhances densification. The high-density undoped SnO 2 ceramics (96.6% of theoretical) was obtained at much lower temperature (1000), ℃ within a much shorter time, compared to the conventional sintering process. The high-density undoped SnO 2 ceramics (96.6% of theoretical) were obtained by SPS, under the condition of temperature:1000 ℃, pressure: 40 MPa, heating-rate: 200 ℃/min, and holding time: 3 min

Proceedings of the 2nd International Conference on Civil, Materials and Environmental Sciences, 2015

The superhydrophobic silica coating has a great performance of self-cleaning which can be applied... more The superhydrophobic silica coating has a great performance of self-cleaning which can be applied in the field of energy saving, anti-icing, drag reduction, etc. In this paper, Trimethyltrimethoxysilane (MTMS) /Trimethylchlorosilan (TMCS) superhydrophobic silica coating with two-layer structure was dip-coated. Atomic force microscope (AFM) images show that the surface morphology of MTMS/TMCS silica coating was in micro and nano level, and Sa value was 231nm, which could achieve good superhydrophobic performance. MTMS/TMCS silica coating has better superhydrophobic performance than MTMS silica coating. The largest contact angle (CA) of MTMS/TMCS silica coating could reach 155.2°, the sliding angle was less than 10°. The MTMS/TMCS silica coating also has good performance of transmittance in the range of visible light and self-cleaning, the transmittance rate could reach more than 95%. All good performances of the MTMS/TMCS silica coating are from its micro and nano surface structure. Modification of TMCS solution would generate a more stable functional group.

ABSTRACT Using high aluminum refractory material as substrate at 1 400 °C, we studied the connect... more ABSTRACT Using high aluminum refractory material as substrate at 1 400 °C, we studied the connections between several oxides such as Fe2O3, MnO2, CuO, and the formation of defects such as coating crack, exfoliation, blistering, erosion, and fading away appeared in the application of high temperature infrared radiation coating. Analyses showed that thermal stress formed during the heating process due to the thermal expansion coefficient differential between the coating and the substrate, and volume effect caused by the crystal transferred when the temperature changed, which resulted in the coating crack and exfoliation. The gas produced by the reactions between components and binder or the components themselves during the heating process caused the coating blistering. The EMPA and XRD analyses show that oxides with low melting point in the penetrating area of the substrate may form eutectic with low melting point and produced thermal defects, which leads to the erosion by penetrating to the substrate. The valent changes of Fe2O3 and MnO2 during the heating process cause the volatilization of the oxides or the pulverization of the coatings, resulting in the coating fades away easily at high temperature for a long time.

Science China Physics, Mechanics and Astronomy, 2011

Two types of Mg-Cu composition system graded density impactors used for complex loading (shock lo... more Two types of Mg-Cu composition system graded density impactors used for complex loading (shock loading and quasi-isentropic compression) are designed by the elastic-plastic hydrodynamic method in this paper. Mixtures of metal powders in the Mg-Cu system are cast into a series of 17 and 25 uniform compositions ranging from 100% Mg to 100% Cu. The graded density impactors are launched to the stationary 10 m aluminum film and 12 mm LiF window targets by a two-stage light-gas gun in the National Key Laboratory for Shock Wave and Detonation Physics Research, Institute of Fluid Physics, CAEP, and the resulting wave profiles are measured with the DISAR system. Hydrodynamic simulation results are perfectly consistent with the experiments. Our work in this paper will set up a foundation for further research of controllable loading/releasing routes and rate experiments in the future.

Journal of Materials Science, 2014

ABSTRACT In this study, we conducted the diffusion bonding of Mg and Al alloys using a 30-μm-thic... more ABSTRACT In this study, we conducted the diffusion bonding of Mg and Al alloys using a 30-μm-thick pure silver foil interlayer at median temperatures between 390 and 490 °C. We obtained a multilayered structure across the Mg–Ag–Al joint: Mg/Mg(ss, Ag)/Mg3Ag/MgAg/Ag/Ag(ss, Al)/Ag2Al/Al. The silver diffusion barrier prevented the formation of brittle intermetallics between Mg and Al. Intermetallics identified at the joint interface include the more ductile types between Mg and Ag, ε-Mg3Ag and β′-MgAg, and Ag and Al, δ-Ag2Al. As the bonding temperature increased, Ag2Al, followed by MgAg, favored the growth of Mg3Ag IMC layer. The shear strength of the joints increased with the rising bonding temperature to a maximum value of 11.8 MPa at 470 °C. Fracture failure in the joints mainly occurred in the Ag2Al layer. The formation mechanism for interfacial layers in the joints is believed to consist of four stages: (1) solid-solution formation, (2) Mg–Ag IMC formation, (3) Ag–Al IMC formation, and (4) growth of Mg–Ag and Ag–Al IMCs.

Materials Science Forum, 2005

In the present paper, the relationship between characteristic wave impedance and compositions was... more In the present paper, the relationship between characteristic wave impedance and compositions was mainly investigated in order to find a suitable theoretical model for predicting the impedance value of Ti-Mo system composites and FGM. At first, dense Ti-Mo composites with different weight fractions of Mo were prepared. Then the transverse and longitudinal wave velocities of the samples were measured and the characteristic wave impedance values were obtained. A mixture model was adopted to estimate the characteristic wave impedance value of Ti-Mo composites. Comparisons between the estimated and experimental results demonstrated that the suggested model was sufficiently accurate to predict the characteristic wave impedance value of Ti-Mo system composites and FGM.

Scientia Sinica Physica, Mechanica & Astronomica, 2014

Materials Letters, 2012

ABSTRACT

Materials Letters, 2012

ABSTRACT

Journal of Physics: Conference Series, 2013

ABSTRACT In this paper, the particle co-sedimentation process is analyzed by discrete element ana... more ABSTRACT In this paper, the particle co-sedimentation process is analyzed by discrete element analysis. The formation of deposits of continuous functionally graded materials derived from the particle co-sedimentation method is simulated. The porosity of the deposit is calculated and the variation of the porosity along the deposition direction is obtained. From the simulation, the method to increase the deposit density is firstly generated, which is helpful for preparation of functionally graded materials by particle co-sedimentation method.

Journal of Physics: Conference Series, 2013

ABSTRACT Mg-Al bonded composite materials expand Mg and Al alloys' applications by combin... more ABSTRACT Mg-Al bonded composite materials expand Mg and Al alloys' applications by combining their unique performances together. However, the formation of Mg-Al intermetallic compounds in interface zone of Mg/Al directly-bonded joint seriously obstructs its further development. To solve this problem, Mg-Ag-Al multilayer composite materials have been successfully prepared by diffusion bonding technology. The effect of key process parameter (bonding temperature) on microstructure of this material has been mainly investigated. The results show that Mg and Al were well bonded by using silver interlayer when the bonding temperature exceeded 370°C. But Mg17Al12 and Mg2Al3 compounds were formed in the interface zone at temperatures higher than 420°C. By means of controlling the bonding temperature (380 °C-420 °C), silver interlayer effectively restrained the generation of Mg-Al intermetallic compounds, and Mg-Ag intermetallic compounds (Mg3Ag, MgAg) were formed in the interface zone instead.

Journal of Alloys and Compounds, 2012

Journal of Alloys and Compounds, 2013

Diffusion bonded Mg-Al joints with and without an interlayer were produced. An Ni foil interlayer... more Diffusion bonded Mg-Al joints with and without an interlayer were produced. An Ni foil interlayer eliminated the formation of Mg-Al intermetallic compounds, while addition of an Al thin film to the interlayer improved the properties of the Mg-Ni intermetallic compounds. The shear strength of the joints was improved by the addition of the Ni foil and Al thin film interlayer.

IOP Conference Series: Materials Science and Engineering, 2011

Dense SnO2-based electrode ceramics have extensive application prospect in glass electric-melting... more Dense SnO2-based electrode ceramics have extensive application prospect in glass electric-melting industry due to the excellent electrically-conductive and chemical property in high temperatures and oxidation environment. In this paper, dense SnO2-based electrode ceramics doped with MnO2 and Sb2O3 were prepared by pressureless sintering method and the corrosion rate in soda-lime glass liquid as well as the microstructure evolution was mainly

Fire and Materials, 2012

Compact silicone/alumina composite was obtained by highly filling aluminum oxides and hydroxides ... more Compact silicone/alumina composite was obtained by highly filling aluminum oxides and hydroxides in silicone resin. The flexural strength and dimensional change of the silicone/alumina composite after being fired has have been studied. It presented a special fire resistance, which could well coordinate the contradiction between the mechanical strength retention and the dimensional stability of silicone-based composite in case of catching fire. Thermogravimetric analysis, scanning electron microscopy, X-ray diffraction, transmission electron microscopy, and electron dispersion spectroscopy were applied to systematically explore the process of the in-suit organic-to-inorganic transformation. A possible mechanism was proposed to illustrate the phenomenon of the high strength retention and dimensional stability of silicone/alumina composite under fire.