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基于ANSYS的HFCVD金刚石厚膜的热应力分析 总被引:2,自引:0,他引:2
金刚石膜中的热应力会削弱金刚石薄膜与基底之间的粘结强度和金刚石膜的机械性能,更严重的会使CVD膜产生热裂纹甚至出现"炸膜"现象.本文根据HFCVD金刚石膜沉积过程中实际工作状态的边界条件,通过有限元软件ANSYS计算分析HFCVD金刚石膜中的热应力分布,并通过实验进行了验证,获得了HFCVD膜中热应力的分布规律以及金刚石膜半径、厚度、沉积温度和冷却速度四项实验条件对热应力的影响.研究结果表明:热应力沿径向分布是不均匀的,在边缘部分有突变;金刚石膜的膜厚,冷却速度和沉积温度对金刚石膜中的热应力影响很大,而金刚石膜的半径对膜中热应力影响较小,从而为HFCVD金刚石膜中热应力的预测与控制提供依据. 相似文献
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本文使用金刚石磨料作为晶种颗粒,通过热丝化学气相法生长出单晶金刚石颗粒,并且建立三维的有限元模型,利用有限元仿真分析了生长过程中影响金刚石磨料生长速率以及沉积质量的各种因素,如热丝的排列方式,衬底的温度场,以及晶种的分布方式.通过固定在热丝CVD反应腔里的热电偶测量了实际的衬底温度分布,从而验证了仿真结果的正确性.另外,通过改变仿真模型优化了沉积单晶金刚石颗粒的工艺参数,获得适应于合成单晶金刚石颗粒的新技术,为化学气相沉积合成单晶金刚石颗粒奠定了基础,也为高温高压金刚石磨料品级的改进与提高提供了新途径. 相似文献
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金刚石涂层的纳米压痕力学性能研究 总被引:3,自引:1,他引:2
用HFCVD法在硬质合金刀具上制备了CVD金刚石涂层,利用纳米压痕仪研究了CVD金刚石涂层的硬度和弹性模量等力学性能.结果表明,反应室气压、衬底温度、反应气体中CH4含量、沉积时间等参数改变了CVD金刚石膜中sp2成分含量、晶界数量及晶界上缺陷,从而影响CVD金刚石涂层的纳米硬度和弹性模量.较高或较低的衬底温度都会导致硬质合金刀具上CVD金刚石涂层的纳米硬度、弹性模量降低;随着反应室气压、反应气体中CH4含量的增加,硬质合金刀具上CVD金刚石涂层的纳米硬度、弹性模量降低;沉积时间低于6 h时,沉积时间对硬质合金刀具上CVD金刚石涂层的纳米硬度、弹性模量影响显著,沉积时间超过6 h后,沉积时间对硬质合金刀具上CVD金刚石涂层的纳米硬度、弹性模量逐渐趋向稳定. 相似文献
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直流等离子体喷射制备无裂纹自支撑金刚石膜体的晶体组织设计 总被引:4,自引:3,他引:1
在自支撑金刚石膜体中发现网状、河流状和环状三种裂纹形式,这几种裂纹形式依沉积温度不同而不同.首次采用了原子力显微镜分析了金刚石自支撑膜体裂纹断裂机制,发现了穿晶断裂和沿晶断裂两种机制,其中,在网状裂纹中,穿晶断裂机制占主要地位;环状裂纹中,沿晶断裂机制占主要地位,而河流状裂纹是两种机制的混合.对应X射线衍射结果,(111)晶面占优的膜体易于开启穿晶断裂机制,(220)晶面占优的膜体易于开启沿晶断裂机制.使用Raman 谱测试的膜体中的本征应力在几十到几百MPa之间,且在膜体中存在应力剖面分布.Raman谱的结果还显示低缺陷的膜体组织有利于阻挡裂纹扩展.通过建立简单力学分析模型,推测了膜体组织对断裂强度的作用.根据实验结果和力学模型,制备了最厚2mm、最大直径120mm的无裂纹自支撑金刚石膜. 相似文献
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We perform first-principles coexistence simulations of the low-density and the high-density phases of supercooled liquid silicon and find a negative slope for the coexisting line in the temperature-pressure plane. Electron density maps and electron-localization function plots of the two phases of silicon show marked differences. The calculated differences suggest more localized electrons in the low-density liquid compared to the high-density liquid, coming from an increased population of covalent bonds, which further explain the calculated negative slope in the two phase coexistence regime. This is consistent with the presence of a pseudo-gap in low-density liquid silicon, absent in the high-density liquid which shows a metallic behavior. 相似文献
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A. L. Bingham J. E. Drake C. Gurnani M. B. Hursthouse M. E. Light M. Nirwan R. Ratnani 《Journal of chemical crystallography》2006,36(10):627-630
Triethyl ammonium Salt of O,O′-bis(p-tolyl)dithiophosphate and O,O′-bis(m-tolyl)dithiophosphate have been obtained by reaction of p- and m-cresol, respectively with P2S5 in toluene and have been characterized by elemental analysis, IR, 1H and 31P NMR spectroscopy. The molecular structure of O,O′-bis(p-tolyl)dithiophosphate has been determined. Crystal data: [Et3NH]+[(4-MeC6H4O)2PS2]−: Monoclinic, P21/c, a=15.2441(9) ?, b=10.415(2) ?, c=3.9726(9) ?, β=91.709(7)°, V=2217.5(1) ?−3, Z=4.Supplementary materials Additional material available from the Cambridge Crystallographic Data Centre (CCDC no. 600927 for [Et3NH]+[(4-MeC6H4O)2PS2]− comprises the final atomic coordinates for all atoms, thermal parameters, and a complete listing of bond distances and angles. Copies of this information may be obtained free of charge on application to The Director, 12 Union Road, Cambridge CB2 2EZ, UK (fax: +44-1223-336033; email: deposit@ccdc.cam.ac.uk or www:http://www.ccdc.cam.ac.uk). 相似文献
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Tosha Barclay Wallace Cordes Fu-May Yang Shaw-Tao Lin 《Journal of chemical crystallography》1997,27(6):359-362
Structures of both thecis andtrans isomers of dithiahexahydro[3.3]metacyclophane, ?C6H4?CH2SCH2?C6H10?CH2SCH2?, have been determined, wherecis andtrans refer to the attachments to the cyclohexane ring. Thecis form crystallizes in the monoclinic space groupP21/c witha=8.4299(11)Å,b=21.772(2)Å,c=8.9724(13)Å, β=116.574(11)o, andZ=4. Thetrans isomer packs into the monoclinic space groupP21 witha=8.159(16)Å,b=10.185(5)Å,c=9.558(2)Å, β=112.435(18)o, andZ=2. The cyclohexane ring of thecis isomer is in the chair conformation, while the cyclohexane of thetrans isomer is found in a twisted boat conformation. 相似文献
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以表面活性剂CTAB和SDBS为化学添加剂,采用化学共沉淀法对碳酸锶晶体的生长形态进行调控,成功地制备出了实心的树枝状和花瓣为空心的花状碳酸锶粉体,并用X射线衍射(XRD)、扫描电子显微镜(SEM)和傅里叶变换红外光谱(FT-IR)等分析手段对样品进行了表征;最后重点对化学添加剂可能产生的影响机理进行了初步的探讨.结果表明,CTAB和SDBS在晶体生长的过程中能起到显著的影响作用,两者对粒子分散性能的作用效果相反,而且后者对晶体(013)和(213)晶面表面能降低的贡献明显大于前者. 相似文献
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Lin Zhu Karl Seff Thomas Witzke Lutz Nasdala 《Journal of chemical crystallography》1997,27(5):325-329
The structure of Zn4Na(OH)6SO4Cl·6H2O, a secondary mineral from Hettstedt, Germany, was determined by single-crystal X-ray diffraction. The crystals are hexagonal,a=8.413(8),c=13.095(24) Å, space group $P\bar 3$ , Z=2. The structure was refined to R=0.0554 and Rw=0.0903 for 970 reflections with I≥3σ(I). The structure can be described as zinc hydroxide layers perpendicular toc, from which sulfates and chlorides extend. The layers are held together by a system of hydrogen bonds involving hexaaquo Na+ ions which occupy the interlayer space. 相似文献
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Jerry P. Jasinski Ray J. Butcher Anil N. Mayekar H. S. Yathirajan B. Narayana B. K. Sarojini 《Journal of chemical crystallography》2009,39(10):761-765
Abstract The title compound, C18H18BrN3O3S, a derivative of 1,3,4-oxadiazole, crystallizes in the triclinic space group P-1 with unit cell parameters a = 6.8731(3), b = 8.9994(4), c = 15.7099(6) ?, α = 92.779(3)°, β = 130.575(3)°, γ = 107.868(4)°, Z = 2. The dihedral angle between the mean planes of the planar naphthyl and morpholine (chair) rings with the planar oxadiazol
ring is 50.1(8) and 76.8(6)°, respectively. The planar naphthyl ring is twisted 52.2(5)° with the mean plane of the morpholine
ring. A group of four intermolecular close contacts are observed between a bromine atom and hydrogen atoms from the closely
packed naphthyl, morpholine and oxy–methyl groups in the unit cell. These molecular interactions in concert with an additional
series of π–π stacking interactions that occur between the center of gravity of the two 6-membered rings of the naphthalene
group influence the twist angles of each of these three groups. A MOPAC AM1 calculation of the conformation energy of the
crystal structure [226.0128(9) kcal] compared to that of the minimum energy structure after geometry optimization [29.9744(1) kcal]
reveals a significantly reduced value. The twist angles of the three groups above also change after the AM1 calculation giving
support to the influence of both intermolecular C–H···Br short-range interactions and Cg π–π stacking interactions on these
angles which therefore play a role in stabilizing crystal packing.
Graphical Abstract Crystal structure of 5-{[(6-bromonaphthalen-2-yl)oxy]methyl}-3-(morpholin-4-ylmethyl)-1,3,4-oxadiazole-2(3H)-thione, C18H18BrN3O3S, is reported and its geometric and packing parameters described and compared to a MOPAC computational calculation.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
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Zun-Ting Zhang Xue-Ling Zhang Bo-Lun Yang Yao-Dong Zhang 《Journal of chemical crystallography》2006,36(7):407-411
Irisolidone (5,7-dihydroxy-6,4′-dimethoxyisoflavone) was isolated from the flowers of Pueraia lobata and its crystal structure was examined by X-ray single crystal diffraction. The crystal structure of irisolidone is monoclinic, space group P21/c with a = 15.491(9) ?, b = 7.895(4) ?, c = 13.321(7) ?, β = 110.546(9)° and Z = 4. Hydrogen bonding and aromatic π–π stacking assemble the title compound into a three-dimensional networking structure. 相似文献
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Maurizio Remelli Fernando Pulidori Remo Guerrini Valerio Bertolasi 《Journal of chemical crystallography》1997,27(9):507-513
The natural amino acid L-Spinacine (4,5,6,7-tetrahydro-1H-imidazo[4,5-c]pyridine-6-carboxylic acid) has been synthesized following a new pathway which gives a chemically and optically pure product with an excellent yield. The crystal structures of a synthetic intermediate, Nπ-hydroxymethyl-spinacine, and a spinacine derivative, Nα-methyl-spinaceamine, have been investigated through X-ray diffraction: Spi(πMeOH)·H2O, monoclinicP2 i,a=8.571(1),b=6.682(1),c=8.588(1) Å, and β=94.67(1)o. Spm(αMe)·2HCl·H2O, triclinicP l,a=7.492(4),b=10.799(3),c=7.040(2) Å, α=91.88(2), β=98.36(3) and γ=73.34(3)o. Spi(πMeOH) crystallizes with a water molecule and displays a zwitterionic character. The carboxylate group is in equatorial position and forms a short electrostatic interaction of 2.618(2) Å between one of its oxygens and the protonated nitrogen of the tetrahydropyridine ring. The crystal packing is assured by strong O?H???O, O?H???N, N?H???N intermolecular hydrogen bonds and C?H???O close contacts. The biprotonated compounds Spm(αMe) crystallizes with two Cl? anions and a water molecule. The positive charge on the imidazole ring is delocalized on the conjugated moiety N=C?N. The crystal is built up by clusters formed by two biprotonated Spm(αMe) molecules, four Cl? anions and two water molecules linked together by hydrogen bonds. 相似文献
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Maurizio Remelli Fernando Pulidori Remo Guerrini Valerio Bertolasi 《Journal of chemical crystallography》1991,27(9):507-513
The natural amino acid L-Spinacine (4,5,6,7-tetrahydro-1H-imidazo[4,5-c]pyridine-6-carboxylic acid) has been synthesized following a new pathway which gives a chemically and optically pure product
with an excellent yield. The crystal structures of a synthetic intermediate, Nπ-hydroxymethyl-spinacine, and a spinacine derivative, Nα-methyl-spinaceamine, have been investigated through X-ray diffraction: Spi(πMeOH)·H2O, monoclinicP2
i,a=8.571(1),b=6.682(1),c=8.588(1) ?, and β=94.67(1)o. Spm(αMe)·2HCl·H2O, triclinicP
l,a=7.492(4),b=10.799(3),c=7.040(2) ?, α=91.88(2), β=98.36(3) and γ=73.34(3)o. Spi(πMeOH) crystallizes with a water molecule and displays a zwitterionic character. The carboxylate group is in equatorial
position and forms a short electrostatic interaction of 2.618(2) ? between one of its oxygens and the protonated nitrogen
of the tetrahydropyridine ring. The crystal packing is assured by strong O−H−−−O, O−H−−−N, N−H−−−N intermolecular hydrogen
bonds and C−H−−−O close contacts. The biprotonated compounds Spm(αMe) crystallizes with two Cl− anions and a water molecule. The positive charge on the imidazole ring is delocalized on the conjugated moiety N=C−N. The
crystal is built up by clusters formed by two biprotonated Spm(αMe) molecules, four Cl− anions and two water molecules linked together by hydrogen bonds. 相似文献