Interracial Bonding Strength of TiN Film Coated on Si3N4 Ceramic Substrate

The fraction of TiN/Si3N4 in the cross section was observed with scanning electric microscope （SEM）, and residual stresses of TiN coated on the surface of Si3N4 ceramic were measured with X-ray diffraction （XRD）.The hardness of TiN film was measured, and bonding strength of TiN film coated on Si3N4 substrate was measured by scratching method. The formed mechanism of residual stress and the failure mechanism of the bonding interface in the film were analyzed, and the adhesion mechanism of TiN film was investigated preliminarily. The results show that residual stresses of TiN film are all behaved as compressive stress, and TiN film is represented smoothly with brittle fracture, which is closely bonded with Si3N4 substrate. TiN film has high hardness and bonding strength of about 500 MPa, which could satisfy usage requests of the surface of cutting Si3N4 ceramic.     

Problems in the Determination of Internal Stresses in Plasma Assisted CVD TiN Films

The measurement of internal stresses in a PACVD TiN film proved experimentally to be difficult bya conventional X-ray diffraction technique.The linear relationship between 2θ and sin~2(?) couldhardly be reached in some cases.Nevertheless.a good confirmation between the variation ofFWHM-sin~2(?) and 20-sin~2(?) was revealed for every nonlinear forms.It followed that the effect ofnondistributed micro-strains might exist in plasma assisted vapor deposited films,which usuallyhave a strong crystal orientation,and the method of effectively separating macro-stress andmicro-strain must be applied for the precise determination of internal stresses in PACVD films.     

用涂层压入仪测定薄膜与基体结合强度的探讨

用新颖的能连续加载、卸载并配有声发射监测的涂层压入仪 ,对薄膜与基体的结合强度进行了探讨。实验结果表明 ,膜或膜 /基破坏的声发射信号各有特点 ,可区分压入过程中 (含卸载 )开裂和剥落及其对应的载荷值。压入法的临界载荷 pc 为加载过程中使膜发生初始剥落的外载 ,用涂层压入仪可精确测定。 pc 值对基体硬度和表面粗糙度的变化敏感。故用涂层压入仪可以实现用压入法考察膜 /基结合强度     

Investigation of C/Si3N4 Nanocomposites

Nanocrystalline carbon black and graphite micrograins have been added to silicon nitride starting powder and sintering additives (Al₂O₃ and Y₂O₃). These mixtures were mechanochemically activated several hours in a planetary type alumina ball‐mill in order to achieve a homogenous mass. As an alternative to nano‐ and micrograins, carbon fibres have been added to carbon free silicon nitride batches. Sinter‐HIP has been applied to rectangular bars which were earlier dry pressed. Structural and morphological analysis were performed on as‐prepared samples. Bending strength and elastic modulus have been found to be influenced by amount of carbon black and graphite introduced in silicon nitride matrix.     

碳化硅质焊料连接氮化硅/碳化硅陶瓷的性能研究

采用以碳化硅为主相的焊料,在无压的条件下,连接氮化硅结合碳化硅陶瓷.结果表明:焊料在室温到1323K的干燥和烧结过程中,体积稳定,稍有膨胀.在1173K保温3h的条件下,连接的样品拉伸强度达到1.76MPa,热震残余强度保持率为82%.接头致密,并且焊料层与母材显微结构非常相似,界面处有明显的元素扩散,这对于提高结合强度和热震性能有重要作用.     

预溅射时长对TiN镀层成膜情况的影响研究

为了研究预处理阶段工艺参数对镀层性能的影响, 采用阴极弧离子镀方法在钛合金上制备TiN镀层。用金属离子轰击预溅射基底, 对基底的活性和温度进行不同程度的改变。本实验保持温度、真空度、抽气速率及其他电参数固定不变, 仅以轰击预溅射的时长为唯一变量, 分别轰击3、6、9、12、15和18 min, 从而完成对镀层成膜情况的对比研究。利用扫描电子显微镜来观察镀层断面结构, 利用维氏硬度计测量显微硬度, 采用划痕法来判定镀层与基底的结合强度, 通过摩擦磨损实验来测试薄膜的耐磨性。测试结果表明, 随着轰击时间的延长, 基片活性增加, 有利于形核和薄膜生长, 沉积速率、膜基结合强度和耐磨性均呈规律性增加。当轰击时间为15 min时, 膜基之间粘附性达到最佳, 膜基结合力大于65 N, 耐磨性能较好, 成膜情况最优。过度延长轰击时间后, 基片沉积温度过高, 内应力增大, 结合强度和耐磨性能反而下降。实验证明, 通过调整轰击时间可以改善镀层性能, 最终达到沉积速率、硬度、结合强度和耐磨性能的优化配置。     

X射线测量高速钢上不同厚度氮化钛涂层残余应力

采用多弧离子镀在AISIM2高速钢(HSS)上沉积了TiN硬涂层,试样中基体厚度为1mm,涂层厚度分别为3.0、5.0、7.0、9.0和11.0μm.应用X射线衍射(XRD)分析了TiN涂层中残余应力,测量了TiN(220)衍射晶面在五种不同倾斜角(Ψ=0°,20.7°,30°,37.8°和45°)下的X射线衍射峰.结果表明:在3～11μm涂层厚度范围内,TiN涂层中均表现出残余压应力且残余压应力值较大.TiN涂层中残余应力大致分布在-3.22～-2.04GPa之间,本征应力分布在-1.32～-0.14GPa,热应力约为-1.86～-1.75GPa.TiN涂层中残余应力值随涂层厚度变化是非线性增加的,随厚度增加表现出先增大后减小的变化趋势,多项式拟合后发现约在8.5μm厚时残余应力达到最大值.     

TiN/Si3N4纳米多层膜的生长结构与超硬效应

采用磁控溅射方法制备了一系列不同Si3N4和TiN层厚的TiN/Si3N4纳米多层膜,采用X射线衍射、高分辨电子显微分析和微力学探针表征了薄膜的微结构和力学性能,研究了Si3N4和TiN层厚对多层膜生长结构和力学性能的影响.结果表明:当Si3N4层厚小于0.7 nm时,原为非晶的Si3N4在TiN的模板作用下晶化并与之形成共格外延生长的柱状晶,使TiN/Si3N4多层膜产生硬度和弹性模量异常升高的超硬效应.最高硬度和弹性模量分别为34.0 GPa和353.5 GPa.当其厚度大于1.3 nm时,Si3N4呈现非晶态,阻断了TiN的外延生长,多层膜的力学性能明显降低.此外,TiN层厚的增加也会对TiN/Si3N4多层膜的生长结构和力学性能造成影响,随着TiN层厚的增加,多层膜的硬度和弹性模量缓慢下降.     

等离子体浸没式离子注入-离子束增强沉积TiN膜研究

本文采用一种新型的等离子体浸没式离子注入 离子束增强沉积的技术(PIII IBAD),在Cr12MoV钢基体上制备出了TiN膜,对沉积膜的组织进行了光电子能谱分析,并对沉积膜进行了硬度检测、摩擦试验及磨痕形貌分析。试验结果表明,沉积膜中的组织为TiN、TiO2和Ti2O3,TiN膜具有高达Hv3200的高硬度和极其优良的摩擦性能。     

离子束流密度和基底温度对TiN纳米薄膜性能的影响

采用低能离子束辅助沉积技术在Si片上制备了TiN纳米薄膜.考察了离子束流密度和基底温度对薄膜性能的影响.研究表明:随着离子束流密度的增大,TiN薄膜的纳米硬度上升,膜基结合力变化不大,薄膜的耐磨性获得了很大改善;制膜时的基底温度升高,薄膜的硬度也会上升,但膜基结合力下降,摩擦系数增大,薄膜的耐磨性下降.     

Si3N4复相陶瓷半固态连接的接头组织和界面反应

根据复合材料的强化原理,用Ag-Cu-Ti钎料和TiN颗粒作为复合连接材料在半固态下连接Si3N4复相陶瓷以提高接头强度,研究了接头的组织和界面反应.结果表明,接头由母材/反应层/含微量Ti的Ag-Cu TiN/反应层/母材组成,反应层由含Ti、Si、N三种元素的一些化合物组成;TiN颗粒在Ag-Cu基体中的分布总体均匀,两者之间的界面清晰、结合致密:当TiN的加入量较小时,对连接材料与母材的界面反应没有明显影响.初步的剪切试验结果表明,采用Ag-Cu-Ti加TiN颗粒作为复合连接材料连接Si3N4陶瓷可以提高接头强度.     

Optimisation of post-drawing treatments by means of neutron diffraction

The mechanical properties and the durability of cold-drawn eutectoid wires (especially in aggressive environments) are influenced by the residual stresses generated during the drawing process. Steelmakers have devised procedures (thermomechanical treatments after drawing) attempting to relieve them in order to improve wire performance. In this work neutron diffraction measurements have been used to ascertain the role of temperature and applied force – during post-drawing treatments – on the residual stresses of five rod batches with different treatments. The results show that conventional thermomechanical treatments are successful in relieving the residual stresses created by cold-drawing, although these procedures can be improved by changing the temperature or the stretching force. Knowledge of the residual stress profiles after these changes is a useful tool to improve the thermomechanical treatments instead of the empirical procedures used currently.     

Effect of heating on the residual stresses in TiN films investigated using synchrotron radiation

The structure and residual stresses of TiN films deposited by arc ion plating (AIP) on a steel substrate were investigated using a synchrotron radiation system that emits ultra-intense X-rays. In a previous study, the crystal structures of TiN films deposited by AIP were found to be strongly influenced by the bias voltage. When high bias voltages were used, TiN films that were approximately 200 nm thickness had a preferred orientation of {110}, whereas TiN films that were approximately 600 nm thickness has a multilayer film orientation of {111}/{110}. In this present study, the two-tilt method was used to evaluate the residual stresses in TiN films by measuring lattice strains in two directions determined by the crystal orientation. Residual stresses in 600-nm-thick as-deposited TiN films were found to be −10.0 GPa and −8.0 GPa for {111}- and {110}-textured layers, respectively, while they were −8.0 GPa for {110}-textured layers in 200-nm-thick as-deposited TiN films. Residual stresses of both films relaxed to thermal stress levels upon annealing.     

用离子束刻蚀的方法评价铬镀层与基体界面的结合强度

为了探讨激光淬火基体对镀铬层界面结合强度的影响及定性评价金属镀层与界面结合强度的方法,利用离子溅射设备和高分辨率扫描电镜,对激光离散淬火的30CrNi：MoV镀铬层界面进行离子束刻蚀和界面损伤形貌分析,并与靶场试验结果进行对比。结果表明：离子束刻蚀形成的界面损伤形貌与界面结合强度密切相关,界面损伤程度小的对应高界面结合强度,界面损伤程度大的对应低界面结合强度;利用离子束刻蚀技术定性地评价镀铬层的界面结合强度是可行的;激光淬火基体能够提高镀铬层的界面结合强度。     

等离子喷涂氧化铝涂层界面状态和结合性能的研究

采用相同的等离子喷涂工艺参数对TC4钛合金、45钢、6061铝合金和纯铜等不同基材进行了等离子喷涂工艺试验.利用金相显微镜和扫描电镜观察了涂层组织的界面结合状态,测试了不同基材上涂层的结合强度,分析了基材性质不同对涂层残余应力、界面组织状态和结合强度性能的影响规律.结果表明:基材的热膨胀系数、导热系数、比热容等物性参数直接影响涂层的残余应力和界面结合状态,进而影响到涂层与基体的结合强度,针对不同的基材制定不同的喷涂工艺是改善涂层界面结合性能的重要途径.     

添加TiN改善Si3N4陶瓷加工性的研究

通过添加ＴｉＮ改善Ｓｉ３Ｎ４陶瓷的加工性,结果表明,添加ＴｉＮ含量达３０ｗｔ％,可实现电火花切割加工。     

YBCO Superconducting Film Coated on LaAlO3 Substrate by TFA-MOD Process

Epitaxial YBCO film was coated on (001) LaAlO₃ single-crystal substrate by metalorganic deposition of metal trifluoroacetate precursors. From XRD and EDS analysis, it was observed that the film contains CuO or Cu₂BaO₂ segregation, but transport measurement found the segregation structure does not severely prevent the percolation of supercurrent-carrying material. The YBCO films performance is up to 2.4 MA/cm² with I_c of 137 A/cm-width at 77 K and 0 T, and superconducting transition temperature T_c reaches around 91.3 K with sharp transition temperature T_c of 0.36 K.     

脉冲激光沉积法在Si(111)衬底上生长高c轴取向LiNbO3薄膜

在氧压20Pa,衬底温度600℃,靶材与衬底距离4cm的最优化条件下,利用脉冲激光沉积(PLD)技术首次在无诱导电压和任何缓冲层的情况下,在单晶Si(111)衬底上生长具有优良结晶品质和高c轴取向的LiNbO3晶体薄膜.利用X射线衍射(XRD)、扫描电子显微镜(SEM)和原子力显微镜(AFM)对LiNbO3薄膜的结晶品质,择优取向性以及表面形貌进行了系统的分析.结果表明生长出了具有优异晶体质量的c轴取向LiNbO3薄膜,表面光滑平整且无裂纹产生,表面粗糙度约4.8nm,有利于硅基光电子器件的制备和利用.     

异质外延MgO/SrTiO3薄膜中界面应力研究

本文利用激光分子束外延(LMBE)技术在SrTiO3(100)单晶基片上外延生长MgO薄膜，同时又在MgO(100)单晶基片上外延生长SiO3(STO)薄膜。通过反射高能电子衍射(RHEED)仪原位实时监测薄膜生长，研究薄膜的生长过程。并结合X射线衍射(XRD)仪来分析在不同的生长条件下，不同应力对薄膜外延生长的影响。在压应力情况下，MgO薄膜在STO基片上以单个晶胞叠层的方式生长，即以“Cubicon Cubic”方式进行外延；在张应力情况下，由于膜内位错较多，STO薄膜在MgO基片上以晶胞镶嵌的方式进行生长，即以“Mosaic”结构进行外延；提高生长温度，可以减少膜内位错，提高外延质量，使STO薄膜在MgO基片上以较好的层状方式外延生长。     

Influence of Ti/TiN bilayered and multilayered films on the axial fatigue performance of Ti46Al8Nb alloy

The effects of Ti/TiN bi- and multilayered films on the fatigue performance of the Ti46Al8Nb alloy were investigated. Ti/TiN films with a total thickness of 1 μm were deposited on the Ti46Al8Nb alloy substrate by the hollow cathode deposition method. The samples were examined with various analytical techniques including nanoindentation, scratch test, stripping layer substrate curvature test and scanning electron microscopy. The results show that multilayered Ti/TiN films can enhance the fatigue strength of the Ti46Al8Nb alloy, whereas bilayered films have no obvious effect. Compared with the bilayer, the multilayer exhibits higher hardness, higher residual compressive stress and higher adhesion strength to the substrate. It is also demonstrated that the multilayer is responsible for retarding fatigue crack growth. All the superior properties make the hard Ti/TiN multilayer to be an effective protection coating for the enhanced fatigue strength of the brittle substrate.