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Experimental study on combustion characteristics of Chinese RP-3 kerosene

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Chinese Journal of Aeronautics 2016年第2期29卷 375-385页

作者： ma hongan Xie maozhao Zeng Wen Chen Baodong School of Energy and Power Engineering Dalian University of Technology Liaoning Key Laboratory of Advanced Test Technology for Aerospace Propulsion System Shenyang Aerospace University

In order to illustrate the combustion characteristics of RP-3 kerosene which is widely used in Chinese aero-engines, the combustion characteristics of RP-3 kerosene were experimentally inves- tigated in a constant volume combustion chamber. The experiments were performed at four different pressures of 0.1 MPa, 0.3 MPa, 0.5 MPa and 0.7 MPa, and three different temperatures of 390 K, 420 K and 450 K, and over the equivalence ratio range of 0.6-1.6. Furthermore, the laminar combus- tion speeds of a surrogate fuel for RP-3 kerosene were simulated under certain conditions. The results show that increasing the initial temperature or decreasing the initial pressure causes an increase in the laminar combustion speed of RP-3 kerosene. With the equivalence ratio increasing from 0.6 to 1.6, the laminar combustion speed increases initially and then decreases gradually. The highest laminar combustion speed is measured under fuel rich condition （the equivalence ratio is 1.2）. At the same time, the markstein length shows the same changing trend as the laminar com- bustion speed with modification of the initial pressure. Increasing the initial pressure will increase the instability of the flame front, which is established by decreased markstein length. However, different from the effects of the initial temperature and equivalence ratio on the laminar combustion speed, increasing the equivalence ratio will lead to a decrease in the markstein length and the stability of the flame front, and the effect of the initial temperature on the markstein length is unclear. Further- more, the simulated laminar combustion speeds of the surrogate fuel agree with the corresponding experimental datas of RP-3 kerosene within ~10% deviation under certain conditions.

关键词： Combustion mechanism Combustion stability Laminar combustion speed markstein length RP-3 kerosene

HPHT preparation and Micro-Raman characterization of polycrystalline diamond compact with low residual stress

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Science China(Physics,Mechanics & Astronomy) 2010年第8期53卷 1445-1448页

作者： JIA HongSheng ma hongan GUO Wei JIA XiaoPeng National Laboratory of Superhard materials Jilin UniversityChangchun 130012China

High quality grown polycrystalline diamond compact (PDC) with low residual stress was prepared using the infiltration method with nickel based alloys as the solvent under high temperature and high pressure (HPHT). Scanning electron microscopy (SEM) was used to observe the micro morphology of the diamond layer and the diamond/WC substrate interface. It was found that dense and interlaced microstructure with diamond-diamond (D-D) direct bonding formed in the diamond layer of PDC. Micro-Raman spectroscopy was used to measure the Raman shift of diamonds in the polycrystalline diamond (PCD) layer and the residual stress was calculated based on the Raman shift of diamonds. Experimental results show that the residual stress of PCD layer is compressive stress, and the range of the residual stress is from 0.075 to 0.250 GPa in the whole PCD layer, much lower than that of other reports (up to 1.400 GPa). Moreover, the distribution of the residual stress from the diamond surface layer to the inner cross-section is homogeneous.

关键词： HPHT PCD micro morphology residual stress

Effect of Seed Sizes on Growth of Large Synthetic Diamond Crystals

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Journal of materials Science & Technology 2008年第2期24卷 153-156页

作者： Chuanyi ZANG Rui LI hongan ma Shangsheng LI Xiaopeng JIA Institute of material Science and Engineering Henan Polytechnic University Jiaozuo 454000 China State Key Laboratory for Superhard materials Jilin University Changchun 130012 China

For the growth of large synthetic diamond crystals by temperature gradient method （TGM）, the grit sizes of seed crystals have great effects on the growth rate and quality of large grown crystals. Because of the limited area of seed surfaces, the maximum diffusion flux of carbon source, which could be absorbed by the seed, is related to the seed size. And with increasing the seed sizes, the growth rates also increase markedly. However, the seed sizes should be lower than a certain value, which determines the crystal quality directly. For example, with NiMnCo alloy as the metal solvent, when the seed size increases from 0.5 to 1.8 mm, the growth rate increases greatly from about 1.1 to 3.2 mg/h; when the size is beyond 2.0 mm, more and more metal inclusions would be incorporated into the grown crystals, and the crystal quality is destroyed heavily. Finite element analysis （FEA） shows that, due to the special assembly of growth cell, the diffusion of carbon source in the metal solvent is very inhomogeneous, which could be substantiated directly by the appearances and shapes of large grown crystals and the remains of carbon source. And this inhomogeneous diffusion of carbon source would be very harmful to the growth of large diamond crystals, especially when large-size seed crystals are used.

关键词： Temperature gradient method Diamond Inhomogeneous diffusion Finite element analysis

Synthesis of growth-type polycrystalline diamond compact (PDC) using the solvent Fe_(55)Ni_(29)Co_(16) alloy under HPHT

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Science China(Physics,Mechanics & Astronomy) 2012年第8期55卷 1394-1398页

作者： JIA HongSheng JIA XiaoPeng ma hongan LI HaiBo Key Laboratory of Functional materials Physics and Chemistry of the Ministry of Education Jilin Normal University Siping 136000 China State Key Laboratory of Superhard materials Jilin University Changchun 130012 China

A growth-type polycrystalline diamond compact （PDC） was synthesized under high temperature and high pressure （HPHT）. The infiltration technique was used with an Fe55Ni29Co16 （KOV） alloy as the sintering solvent. The morphology and weight ra- tio of the PDC were investigated through scanning electron microscopy （SEM） and electron dispersion spectroscopy （EDS）. Note that the KOV alloy evenly infiltrated throughout the polycrystalline diamond （PCD） layer and WC-Co substrate in a short sintering time due to its low viscosity and high soakage capability. A transition layer confirmed the presence of the M^C phase near the interface of the PDC, which can make the diamond layer and WC-Co substrate combine as a complex material. X-ray diffraction （XRD） performed on the PCD layer confirmed the presence of cubic diamond, WC, cubic CoCx, the high tempera- ture cubic phase of c^-Co, the alloy phase of FeNix, and no graphite phase. Besides, a surface residual stress of the PCD layer, measured with reasonable accuracy using micro-Raman spectroscopy, is found to be a homogeneous compressive stress with an average value of 0.16 GPa, much lower than that of the powders-mixing method.

关键词： HPHT infiltration PDC Fe55Ni29Co16 alloy residual stress

Mechanism of diamond-to-graphite transformation at diamond-stable conditions

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Chinese Science Bulletin 2009年第14期54卷 2535-2538页

作者： ZANG ChuangYi CHEN XiaoZhou HU Qiang ma hongan JIA XiaoPeng Institute of materials Science and Engineering Henan Polytechnic University Jiaozuo 454000 China State Key Laboratory of Superhard materials Jilin University Changchun 130012 China

The diamond-to-graphite transformation at diamond-stable conditions is studied by temperature gradient method (TGM) under high pressure and high temperature (HPHT), although it is unreasonable from the view of thermodynamic considerations. It is found that, at diamond-stable conditions, for example, at 5.5 GPa and 1550 K, with fine diamond grits as carbon source and NiMnCo alloy as metal solvent assisted, not only large diamond crystals, but metastable regrown graphite crystals would be grown by layer growth mechanism, and the abundance of carbon source in the higher temperature region is indispensable for the presence of metastable regrown graphite crystals. From this transformation, it is concluded that, with metal solvent assisted, although the mechanism of crystal growth could be understood by the macro-mechanism of solubility difference between diamond and graphite in metal solvents, from the point of micro-mechanism, the minimum growth units for diamond or graphite crystals should be at atomic level and unrelated to the kinds of carbon source (diamond or graphite), which could be accumulated free-selectively on the graphite with sp2π or diamond crystals with sp3 bond structure.

关键词：宏观调控机制金刚石晶体石墨晶体钻石晶体稳定转化温度梯度法 NiMnCo

Effects of additive boron on HPHT diamond single crystals grown by TGM

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Science China(Physics,Mechanics & Astronomy) 2011年第12期54卷 2186-2190页

作者： XIAO HongYu QIN YuKun LI ShangSheng LIANG ZhongZhu ma hongan JIA XiaPeng Department of mathematics and Physics Luoyang Institute of Science and Technology Luoyang 471023 China Henan Polytechnic University Jiaozuo 454000 China State Key Laboratory of Applied Optics Changchun Institute of Optics Fine Mechanics and Physics Chinese Academy of Sciences Changchun 130033 China National Lab of Superhard materials Jilin University Changchun 130012 China

In this work, under pressure 5.4 GPa and temperature 1250-1400°C, large gem-diamond single crystals with perfect shape and different content of additive boron were synthesized using temperature gradient method. High-purity boron powders were added as boron source into the graphite powder, and the effects of additive boron on crystal growth habit were investigated in detail. The relationship between the growth rate and the amount of additive boron was studied. The scanning electron microscopy was employed to study the morphology of boron-doped diamond crystals. Raman spectroscopy and Hall measurements were used to investigate the crystal structures and the carrier concentration, respectively. The results show that with the increase of the content of boron added into graphite powder, the crystal growth rate and the carrier concentration increase firstly, and decrease afterwards, and the zone-center phonon line at 1332 cm 1 has small shift to lower energy. The defects occur on the crystal surface when excessive boron is added in the synthesis system.

关键词： HPHT boron-doped diamond catalyst carrier concentration

Effects of initial crystal size of diamond powder on surface residual stress and morphology in polycrystalline diamond (PCD) layer

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Science China(Physics,Mechanics & Astronomy) 2011年第1期54卷 98-101页

作者： JIA HongSheng JIA XiaoPeng XU Yue WAN LianRu JIE KaiKai ma hongan State Key Laboratory of Superhard materials Jilin University Changchun 130012 China Test Science Experiment Center Jilin University Changchun 130021 China

Polycrystalline diamond compacts (PDC) were synthesized using diamond powder of average crystal size 3-20 μm by the Ni 70 Mn 25 Co 5 alloy infiltration technique at high temperature and high pressure (HPHT).The surface residual stress of polycrystalline diamond (PCD) layer was measured using micro-Raman spectroscopy with hydrostatic stress model and X-ray diffraction (XRD).Measurements of the stress levels of PCDs show that the residual compressive stresses range from 0.12 to 0.22 GPa,which increase with the crystal size of *** electron microscopy (SEM) was used to observe the morphology of initial diamond grains and PCD *** results indicate that PCD has a dense and interlaced microstructure with diamond-diamond (D-D) direct *** the smaller the crystal size of diamond,the better the growth of diamond direct bonding and the smaller the binder metal between diamond boundaries will be.

关键词： HPHT polycrystalline diamond (PCD) crystal size residual stress morphology

Effects of aluminum additive on diamond crystallization in the Fe-Ni-C system under high temperature and high pressure conditions

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Science China(Physics,Mechanics & Astronomy) 2012年第5期55卷 781-785页

作者： ZHANG ZhuangFei JIA XiaoPeng LIU XiaoBing HU MeiHua LI Yong YAN BingMin ma hongan State Key Laboratory of Superhard materials Jilin UniversityChangchun 130012China

In this paper, we investigate diamond crystallization in Fe-Ni-C with an aluminum additive and the capability of aluminum for converting graphite to diamond in a series of experiments at 4.9-5.5 GPa and 1240-1500℃. Our experimental results show that the growth habits of diamond crystal have been significantly influenced by the addition of aluminum as a catalyst. The crystal color changes from yellow to nearly colorless. The morphology of the synthesized diamond crystals gradually changes from cubic-octahedron to octahedron in the Fe-Ni-C systems with increasing aluminum additive. The lowest synthesis conditions fell first and then rose with increasing aluminum. We found a suitable addition of aluminum is very effective in lowering the synthesis conditions while an excessive aluminum additive may have a suppressive effect on the diamond nucleation.

关键词： crystal morphology diamond aluminum additive

Synthesis of high quality type-Ib diamond crystals in carats grade

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Chinese Science Bulletin 2010年第14期55卷 1372-1375页

作者： XIAO HongYu JIA XiaoPeng ma hongan LI ShangSheng LI Yong ZHAO Ming State Key Laboratory of Superhard materials Jilin University Changchun 130012 China

High quality type-Ib tower-shape gem-diamond crystals in carats grade were synthesized in cubic anvil high pressure apparatus (SPD-6×1200) at 5.4 GPa and 1250-1450°C. The relationship between the growth time and the weight of growth diamond has been gained. The faces of {110} and {113} were found in the synthetic diamond crystals frequently. We found that the relative growth rate of {113} face was descending with the increase of growth temperature, and that of {110} face had no obvious change with the increase of the growth temperatures and the growth time. In the work, the crystal defects were studied carefully, and the reasons for the appearance of the defects were also obtained. Some diamond crystals have been polished into the anvil of DAC (Diamond Anvil Cell) and the diamond jewelry. Compared with natural diamond crystal, synthetic diamond crystal has the merits such as small grinding quantity, low cost, etc., so it can be widely used in super high pressure field and gemstone industry.

关键词：宝石级金刚石单晶合成克拉金刚石晶体质型经济增长生长温度钻石首饰