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Liang B.-Y.,Zhongyuan University of Technology | Liang B.-Y.,Zhengzhou Sino Crystal Diamond Joint stock Co. | Mu Y.-C.,Zhongyuan University of Technology | Fan P.,Zhongyuan University of Technology
Fenmo Yejin Cailiao Kexue yu Gongcheng/Materials Science and Engineering of Powder Metallurgy | Year: 2013

AlN-SiC solid-solution materials were fabricated by chemical oven induced thermal explosion using Al, Si and C0.36N0.64 powders as raw materials. The phase composition of the synthesized samples was determined by XRD. The morphology of the sample was observed by SEM. The results show that AlN-SiC solution materials can be synthesized by thermal explosion. The single phase AlN-SiC solid-solution materials may be obtained by adding excessive C0.36N0.64 powders. The sample contains many hexagonal platelets AlN-SiC solid-solution grains with the edges length of 1.5 and 20 μm, respectively. The reaction mechanism for synthesizing of AlN-SiC solid-solution was researched by combining thermo- dynamics and kinetics analysis. At first, the C0.36N0.64 is decomposed to C and N2, and then, Al reacts with N2 to form AlN releasing amounts of heat which induces the occurrence for thermal explosion reaction; finally, AlN reacts with Si and C, or Si3N4 reacts with C and N2 to form AlN-SiC solution. Source


Liang B.-Y.,Zhongyuan University of Technology | Liang B.-Y.,Zhengzhou Sino Crystal Diamond Joint stock Co. | Zhang J.,CAS Zhengzhou Research Institute | Mu Y.-C.,Zhongyuan University of Technology
Fenmo Yejin Cailiao Kexue yu Gongcheng/Materials Science and Engineering of Powder Metallurgy | Year: 2013

The V2AlC material was combustion synthesized using V, Al, C as raw materials. The effects of two kinds of combustion synthesis method, thermal explostion and self propagation high temperature synthesis (SHS) technology on the synthesis of V2AlC were investigated. The phase composition and morphology of the products were analysised by XRD and SEM. V-Al-C system was analysized by thermodynamic. The reaction mechanism for synthesising V2AlC was also studied. The results show that, the product in the thermal explostion synthesized sample is V2AlC and small amounts of VCx and AlV3, and V2AlC grain is lath shape with the length of about 10 μm. Adding excess Al in the raw materials can remove AlV3 phase and enhance the synthesis of V2AlC, but single V2AlC phase can not be obtained. Adding suitable Sn can enhance the synthesis of single V2AlC phase. In the SHSed sample, the major product is V2AlC and small amount of product is VC0.75. Adding excess Al in the raw materials can enhance the synthesis of single phase V2AlC. The adiabatic temperature of 2V-Al-C system is 2767 K. Besides, one reaction mechanism for synthesizing V2AlC has been proposed, which suggests that V2AlC with grain shape like lath might be formed from V-Al liquid and solid VC. Source


Liang B.-Y.,Zhengzhou Sino Crystal Diamond Joint stock Co. | Liang B.-Y.,Zhongyuan University of Technology | Zhao Q.-G.,Zhengzhou Sino Crystal Diamond Joint stock Co. | Li Y.,Zhengzhou Sino Crystal Diamond Joint stock Co. | Li Z.-J.,Zhengzhou Sino Crystal Diamond Joint stock Co.
Jingangshi yu Moliao Moju Gongcheng/Diamond and Abrasives Engineering | Year: 2013

Ti2AlC ceramic boned diamond composites were fabricated by self-propagation high temperature sintering (SHS) from Ti/Al/C/Diamond powders. Effect of different raw materials ratio on phase composition and microstructure of SHS samples were studied. The samples were analyzed by XRD, SEM with EDS. The result show that the samples occur SHS reaction by ignited. TiAl phases were obtained by SHS from 2Ti/Al/C powders containing mass fraction 20% of diamond. Ti2AlC, TiC and TiAl3 phase were obtained. Meanwhile, the dense transient layer with a thickness of about 4 μm was formed on the face of diamond, making good combination between diamond and matrix. Adding excess Al enhances the synthesis of Ti3AlC2 and TiAl phase of the SHS samples. There was still good combination between diamond and matrix. Source


Liang B.-Y.,Zhongyuan University of Technology | Liang B.-Y.,Zhengzhou Sino Crystal Diamond Joint stock Co. | Mu Y.-C.,Zhongyuan University of Technology
Jingangshi yu Moliao Moju Gongcheng/Diamond and Abrasives Engineering | Year: 2012

Al/Ti/C/CBN mixed powders were used as raw materials for the fabrication of Al/TiC bonded CBN composites by sintering reaction. Samples were analyzed by XRD, SEM and EDS. Results showed that Al/TiC bonded CBN composites were produced by sintering reaction at 1 000 °C for 1 h. If Al mass fraction was low, the main phase of the products was Al and TiC, while if it was higher, the main phase of the products was Al and Al3Ti. Meanwhile, BN reacted with Ti and Al to form A1N and TiB. The phase analysis and fracture morphology of the samples showed that the matrix had a good combination with CBN. Source


Lu J.,Zhongyuan University of Technology | Lu J.,Zhengzhou Sino Crystal Diamond Joint stock Co. | Mu Y.,Zhongyuan University of Technology | Wang Q.,Zhongyuan University of Technology | And 5 more authors.
Jingangshi yu Moliao Moju Gongcheng/Diamond and Abrasives Engineering | Year: 2010

The temperature field in the diamond synthesis chamber when taking indirect heating method was investigated by finite element method', and based on the numerical simulation to the temperature, the diamond synthesis process was optimized in order that the temperature could match with the pressure dynamically. Then the temperature in the synthesis column was calculated and was drown into temperature cloud photograph. The results showed that in the process of heating, the temperature around the graphite tube in the synthesis column was the highest, and after cutting off the power supply, the temperature al the graphite tube went down more quickly, such that the temperature around the center became the highest, and the radial temperature difference was less than 30 °C, thus providing a suitable growing environment for high-quality diamond. The reasons may lie related to the bigger synthesis chamber and the optimization of the heating process. By using optimized synthesis process, high quality diamonds of grain diameter 600∼650 μm were obtained. Source

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