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Xie D.,Hunan University | Wan L.,Hunan University | Song D.,Hunan University | Qin H.,Guangxi Key Laboratory of Superhard Materials | And 11 more authors.
Journal Wuhan University of Technology, Materials Science Edition | Year: 2016

We studied the effects of sintering temperature on FeCuCo based pre-alloyed powder for diamond bits. The FeCuCo composite was fabricated by co-precipitation method. With the addition of tungsten carbide (WC), sintering under different temperatures was investigated. Mechanical properties of the FeCuCo based matrix were systematically studied. The structure of the composite was evaluated by X-ray diffraction (XRD) and scanning electron microscope (SEM) was used to analyze the surface of the powder and matrix. The suitable sintering temperature was determined through differential scanning calorimeter (DSC). Micro drilling experiments were performed, and 820 °C was identified to be the ideal sintering temperature, at which the matrix shows the best mechanical properties and drilling performance. © 2016, Wuhan University of Technology and Springer-Verlag Berlin Heidelberg.


Xie D.-L.,Hunan University | Wan L.,Hunan University | Ning C.-X.,China Nonferrous Metal Guilin Geology and Mining Co. | Ning C.-X.,Chinese National Engineering Research Center for Special Mineral Materials | And 13 more authors.
Rengong Jingti Xuebao/Journal of Synthetic Crystals | Year: 2015

Fe based prealloyed powders were manufactured by co-precipitation method. The mechanical properties of samples sintered at different temperatures were tested. Alloy's structure formed during co-precipitation process was studied by XRD and the morphology was observed by SEM. The results show that the sintering temperature should be less than 900℃ and the mechanical properties of the alloys are the best when sintered at 850℃. The samples sintered at 850℃ have the uniform grain size and best mechanical retention of matrix applied to diamond. ©, 2015, Chinese Ceramic Society. All right reserved.


Xie D.-L.,Hunan University | Wan L.,Hunan University | Liu Z.-H.,Guangxi Key Laboratory of Superhard Materials | Liu Z.-H.,Chinese National Engineering Research Center for Special Mineral Materials | And 13 more authors.
Fenmo Yejin Cailiao Kexue yu Gongcheng/Materials Science and Engineering of Powder Metallurgy | Year: 2015

Fe-Cu based pre-alloyed powder containing Co, Ni and Sn elements was manufactured by co-precipitation method. Metal bond used for diamond tools were fabricated by vacuum hot press sintering Fe-Cu based pre-alloyed powder with adding mass fraction of 25% WC as skeleton phase under the temperatures of 700 to 860℃. Phase composition and morphology of pre-alloyed powder and metal bond were characterized by XRD and SEM. Mechanical properties including hardness, bend strength and abrasion ratio of the sintered matrix were also studied. The results show that solid solution has formed in the pre-alloyed powder owning solid solution phase with fine particle size of about 3 μm, smooth surface and irregular shape was obtained. DSC curve show that the atom diffusion and phase transformation undergo in 820~846℃. The matrix has little pore defect and optimal physical and mechanical properties when sintered at 820℃. The hardness is 113.9 HRB, relative density is 98.86% and bend strength is 1306.4 MPa. Meanwhile the bond force for diamond of the metal bond sintered at 820℃ reaches the maximum value. ©, 2015, Central South University. All right reserved.


Xie D.,Hunan University | Wan L.,Hunan University | Song D.,Hunan University | Wang S.,China Nonferrous Metal Guilin Geology and Mining Co | And 11 more authors.
Materials and Design | Year: 2015

The kinetic characteristics of Fe-Co-Cu pre-alloyed powders in the pressureless sintering process have been investigated. The expansion ratio, linear shrinkage, densification rate and effect of heating rate on the sintering have been analyzed. Based on the classical Arrhenius curve, the sintering activation energy has been calculated. Results show that the samples have a smaller expansion ratio before contracting when the Fe content is higher, and the final linear shrinkage ratio is larger too. The sintering carries out more efficiently and the final linear shrinkage ratio is larger when the samples at a lower heating rate. In the initial and final stage of sintering, the Arrhenius curve is suitable for the Fe-Co-Cu pre-alloyed powders and diffusion is the main transport mechanism. At the initial stage of sintering the sintering activation energy of Fe25%-Co15%-Cu60% powder is 453.11. kJ/mol, Fe45%-Co15%-Cu40% powder is 638.28. kJ/mol and Fe65%-Co15%-Cu20% powder is 504.6. kJ/mol, respectively. At the final stage of sintering the sintering activation energy of Fe25%-Co15%-Cu60% powder is 31.17. kJ/mol, Fe45%-Co15%-Cu40% powder is 20.09. kJ/mol and Fe65%-Co15%-Cu20% powder is 35.13. kJ/mol, respectively. The sintering activation energy in the middle stage is dominated by not only one diffusion mechanism so it is not suitable for the Arrhenius curve. © 2015 Elsevier Ltd.


Liu Z.-H.,Guangxi Key Laboratory of Superhard Materials | Liu Z.-H.,Chinese National Engineering Research Center for Special Mineral Materials | Liu Z.-H.,China Nonferrous Metal Guilin Geology and Mining Co. | Luo W.-L.,China Nonferrous Metal Guilin Geology and Mining Co. | And 6 more authors.
Jingangshi yu Moliao Moju Gongcheng/Diamond and Abrasives Engineering | Year: 2013

The single diamond grit loading experiments on photovoltaic materials namely monocrystalline silicon, polycrystalline silicon and sapphire are done by micro-hardness method. Loading characteristics with single diamond grit to these materials under different force are studied, and the relationship between the force and the loading deepness is analyzed. According to the test results, the diamond's force state and these materials' carving models are analyzed when these materials are cut by diamond tool.


Qin H.,Chinese National Engineering Research Center for Special Mineral Materials | Qin H.,Guilin Research Institute Oj Geology for Mineral Resources | Xie Z.,Chinese National Engineering Research Center for Special Mineral Materials | Xie Z.,Guilin Research Institute Oj Geology for Mineral Resources | And 7 more authors.
Jingangshi yu Moliao Moju Gongcheng/Diamond and Abrasives Engineering | Year: 2010

The sample of the second generation FeCuCo pre-alloyed powder matrix were prepared by using vacuum sintering machine, and the fracture morphology, relative density, hardness and bending strength of matrix at different sintering temperatures were investigated. The results showed that the fracture morphology of matrix was inter granular fracture and trans granular fracture and the grain size of matrix was uniform at different sintering temperatures. With the sintering temperature increasing, the grain size of matrix gradually increased, and no abnormal coarsening of grains was observed. The relative density of matrix slightly increased then kept constant, the hardness of matrix gradually decreased, the beading strength of matrix increased then followed by a decrease. Under the pressure of 30VIPa and a dwell time of 6 minutes, the optimum sintering temperature of the second generation FeCuCo pre-alloyed powder is 850 °C, the relative density of matrix is 97. 5 % y the hardness of matrix is 105.5 11KB and the bending strength of matrix is 1839. 14 MPa. The second generation KeCuCo pre-alloyed powder demonstrates great application potential in replacing pure cobalt powder.

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