金属陶瓷零件近净成形技术

等离子熔射成形技术在金属陶瓷复合材料的近净成形中具有明显的技术优势。通过金属陶瓷零件熔射近净成形实验，详细分析熔射工艺过程和工艺参数对成形件质量的影响。研究表明等离子熔射成形技术可快速制造金属陶瓷零件，实现成形与加工一体化，且工艺简单、成本低，是金属陶瓷复合材料成形技术中很有发展潜力的方法。     

等离子熔射快速制模中机器人运动轨迹生成方法及实践

在机器人等离子熔射快速制模中,熔射轨迹对熔射皮膜的成形性有重要影响。本文提出了由CAM加工轨迹转化为机器人等离子熔射轨迹的方法,避免了以往通过STL文件生成机器人熔射轨迹的繁琐过程。文章重点介绍了如何将CAM加工轨迹转化为机器人熔射轨迹,并对其进行了仿真与实验验证,结果表明:该方法比原有的由STL文件生成机器人熔射轨迹的方法更简便、灵活,更适应机器人等离子熔射制模成形的要求。     

等离子熔射制模过程中皮膜温度场实验研究

开展了等离子熔射制模过程中环行向外、环行向内两种熔射路径的皮膜温度场的实验研究，得出前者的温度低于后者的实验结果，该实验结果与模拟结果一致；对三维汽车覆盖件基体等离子熔射过程中的温度分布规律进行探讨，得到三维熔射基体不同形状特征处的温度分布规律，从而为建立合理的熔射制模工艺提供了依据。     

等离子熔射法快速制作金属零件

对等离子熔射法快速制作金属零件进行实验研究,包括母模制作、母模表面处理、熔射成形、脱模方法、制作后处理.采用该技术,成功制得镍基合金薄壁零件.     

等离子数字化熔射成形SOFC核心部件PEN及复阻抗分析

采用等离子熔射与机器人数字化成形技术相结合的方法制备SOFC瓦楞式核心部件PEN。基于交流复阻抗技术对制备的复合电极的电导率进行分析，并与流延法和等离子熔射结合制备的试样对比；采用经典的Arrhenius公式对试样电导率与温度的关系进行定量分析。结果表明，两种工艺制备的试样的电导率均随温度的升高而增大，呈现出明显的NTC效应；与流延和等离子熔射复合的方法相比，等离子数字化熔射成形工艺因为其连续喷涂成形的特点，可以大幅度降低界面接触电阻，提高试样的电导率。     

等离子熔射制造皮纹件

以精细皮纹熔射成形为例,研究皮纹快速制造的工艺过程,总结工艺过程中的后处理技术,详细分析和评价了影响熔射成形件质量的重要因素,并进行相关的熔射实验。结果表明等离子熔射成形技术可以快速制造精细皮纹件,实现了成形与加工一体化,工艺简单,成本低。     

等离子熔射成形射流温度场采集

等离子熔射成形过程中射流品质直接影响着粉末的熔融状态和飞行特性,从而影响了成形质量,因此射流品质诊断已成为该领域的重要研究课题之一.针对等离子射流高温、高速和能量集中等特点,采用CCD数据采集装置结合计算机图像处理技术,实现了熔射过程射流温度场的实时采集和处理.着重研究射流图像采集的基本原理,建立CCD实时图像采集试验系统,提出高温区数据采集方法,并对采集结果进行伪彩色处理.研究成果对实现熔射成形过程可视化和成形质量的实时反馈控制具有重要意义.     

面向RPST的氩氮等离子射流温度分布的测量

在假定等离子体处于局域热力学平衡与光学薄条件下 ,用谱线绝对强度法测量了在等离子熔射快速制模(RPST)过程中氩氮等离子射流的温度分布。实验由CCD装置采集等离子射流图像 ,通过标定实验建立射流图像灰度和辐射强度之间的函数关系并应用Abel变换最终得到射流的温度场分布。获取的温度场将为RPST熔射工艺的合理设计提供科学依据     

基于CCD等离子射流特性在线监测与分析

等离子射流品质诊断始终是国内外学者关注的热点课题,目前由于受到诊断过程的条件制约,实现熔射过程中射流实时显示还难以进行。本文将采用CCD数据采集装置,结合计算机图像处理技术,研究熔射过程中射流图像的数据实时采集与显示,优化过程参数,结果表明通过在线控制和参数优化,射流的品质能得到极大的提高,研究对熔射过程中射流的反馈控制有重要的参考价值。     

销模式等离子熔射成开法制造陶瓷零件

论述等离子熔射成形法制造陶瓷零件的基本原理与各种方法的工艺特征,着重介绍销模式等离子熔射成形法制造陶瓷零件的工艺过程,以Ａ１２Ｏ３．ＴｉＯ２陶瓷粉末为熔射材料进行制造陶瓷零件的工艺实验,讨论了与之相关的问题。     

Elastic modulus and thermal stress in coating during heat cycling with different substrate shapes

The elastic modulus of a deposit (E_d) can be obtained by monitoring the temperature (∆T) and curvature (∆k) of a one-side coated long plate, namely, a one-dimensional (1D) deformation model. The aim of this research is to design an experimental setup that proves whether a 1D deformation model can be scaled for complex geometries. The setup includes a laser displacement sensor mounted on a robotic arm capable of scanning a specimen surface and measuring its deformation. The reproducibility of the results is verified by comparing the present results with Stony Brook University Laboratory’s results. The ∆k-∆T slope error is less than 8%, and the E_d estimation error is close to 2%. These values reveal the repeatability of the experiments. Several samples fabricated with aluminum as the substrate and 100MXC nanowire (Fe and Cr alloy) as the deposit are analyzed and compared with those in finite element (FE) simulations. The linear elastic behavior of 1D (flat long plate) and 2D (squared plate) specimens during heating/cooling cycles is demonstrated by the high linearity of all ∆k-∆T curves (over 97%). The E_d values are approximately equal for 1D and 2D analyses, with a median of 96 GPa and standard deviation of 2 GPa. The correspondence between the experimental and simulated results for the 1D and 2D specimens reveals that deformation and thermal stress in coated specimens can be predicted regardless of specimen geometry through FE modeling and by using the experimental value of E_d. An example of a turbine-blade-shaped substrate is presented to validate the approach.     

模具制造中的高速加工技术

分析了传统电加工工艺在模县制造中存在的主要问题，介绍了超高速加工技术的主要特点，论述了超高速加工用于模具制造的关键技术，列举了一些应用实例和使用效果，指出了超高速加工技术在模县制造中广阔的应用和发展前景。     

液相色谱-串联质谱法确证人尿中的利他林及其主要代谢物

建立了固相萃取-液相色谱-串联质谱法同时确证人尿中的利他林及其主要代谢物利他林酸的方法。尿样中的药物经反相C₁₈固相萃取柱净化、氮气吹至干,以甲睾为内标,用流动相溶解后进行液相色谱-串联质谱法测定。该方法的最低检出限为5 μg•L^-1;利他林和利他林酸的回收率分别为80.6%和68.4%;批内和批间的相对标准偏差小于6.0%,能满足国际反兴奋剂机构(WADA)对其最低检测能力500 μg•L^-1的要求。     

基于O-O方法的CAPP系统制造资源结构建模

采用O-O技术建模方法，分析了制造资源各组成因素之间的关系、层次分类表示形式，以及制造资源与工艺能力生成之间的密切关系，建立了面向对象的制造资源结构模型。并对制造资源与生产规划调度PPS的关系模型进行了研究。     

气相色谱-串联质谱检测水果、蔬菜中抗蚜威、甲霜灵和克螨特残留量

建立了水果、蔬菜中抗蚜威、甲霜灵和克螨特残留量的气相色谱-串联质谱(EI源)检测方法。样品匀浆后经乙腈提取,提取液浓缩后用石墨氨基柱净化,用V(乙腈)∶V(甲苯)=3∶1的溶液淋洗。采用基质配制农药标准样品以校正基质效应引入的定量误差。3种农药的方法线性范围为0.002~0.500 mg.kg-1,在添加农药标准样品浓度0.002、0.010、0.050 mg.kg-1水平上,3种农药的平均回收率在91.6%~110.6%之间,相对变异系数RSD均低于15%,最低检出限为0.002 mg.kg-1。     

印迹膜电喷雾电离质谱法快速分析尿液中沙丁胺醇

沙丁胺醇(SAL)可促进动物生长,常被非法添加于畜禽饲料中,并可通过食物链进入人体,危害人体健康。目前,沙丁胺醇的分析方法已有很多报道,但对于复杂生物样本中沙丁胺醇的快速定量分析依然存在挑战。为实现这一目标,本研究采用印迹膜电喷雾电离质谱法(MIM-ESI MS)对尿液中的沙丁胺醇进行直接定性和定量分析。结果表明,该方法具有较高的灵敏度,尿液样本的检出限和定量限分别为5 ng/L和10 ng/L,在0.01~10 000 μg/L浓度范围内具有较好的线性关系。该方法无需样品前处理,其分子印迹膜材料具有特异性富集的功能,可实现生物复杂样本中痕量目标物的快速检测。     

气相色谱-燃烧-同位素比值质谱法测定发酵液中尿素δ~(13)C和δ~(15)N

在酸性环境下,尿素与丙二醛-二甲基乙缩醛反应生成2-羟基嘧啶,随后由重氮甲烷甲基化形成2-甲氧基嘧啶。本研究以酵母发酵液为例,建立了气相色谱-燃烧-同位素比值质谱(GC-C-IRMS)法测定发酵液中尿素δ~(13)C和δ~(15)N,并对前处理方法和GC条件进行了优化。结果表明:尿素在不同13 C(0~5%)和15 N(0~10%)标记丰度下,标记量与GC-C-IRMS测定结果的相关性良好,线性相关系数R2分别为0.998和0.999,说明可在极低标记浓度下对尿素中δ~(13)C和δ~(15)N进行准确测定。采用该方法测定了酵母发酵液尿素中δ~(13)C和δ~(15)N,其重复性相对标准偏差分别为0.21‰和0.30‰,再现性相对标准偏差分别为0.23‰和0.29‰。该方法精度高、准确性好,可为低稳定同位素标记尿素示踪实验以及尿素循环代谢研究提供方法基础。     

固相萃取-气相色谱-质谱法测定卷烟主流烟气中4种芳香胺化合物

采用氘代-1-氨基萘作为内标,利用剑桥滤片捕集肯塔基参比卷烟（1R5F、2R4F）烟气,经盐酸超声,二氯甲烷、正己烷萃取,盐酸三甲胺和五氟丙酸酐衍生化,固相萃取仪萃取洗脱纯化后,使用气相色谱-质谱（GC/MS）建立卷烟主流烟气中4种芳香胺化合物的测定方法。4种芳香胺化合物的变异系数均小于5%,回收率在89.8%~106.0%之间,检测限在每支卷烟0.03~0.07 ng之间。该方法具有良好的重复性、准确性,适用于卷烟烟气总粒相物中芳香胺的定量分析。     

On the interdependence between kinetics of friction-released thermal energy and the transition in wear mechanisms during sliding of metallic pairs

Sliding of complying solids is often associated with the release of thermal energy. This energy accumulates within the mechanically affected zone (MAZ) of the rubbing pair. The accumulation of thermal energy within the MAZ tends to maximize the potential energy at the interface. Now, since a maximized potential energy renders the sliding system unstable, one (or both) materials will respond in a manner that consumes (dissipates) part or all of the accumulated energy in order to re-establish system stability or at least equilibrium. The material response may be in many forms: oxidation, crack initiation, wear debris generation, transition in wear mechanism, etc. As such, one may consider that these processes are intrinsic responses by the material to dissipate energy. Moreover, many of these responses are triggered at different stages of rubbing according to the balance between the rate of external thermal energy release (which is a factor of the nominal operation parameters) and the rate of thermal energy accumulation—RTEA (which is mainly a function of thermal transport properties of the rubbing pair). An interesting feature of this view is that the later quantity—RTEA—is directly related to the ability of the particular solid to dissipate thermal loads. This quantity, which is termed here as the heat dissipation capacity (HDC), is directly related to the state of blockage of energy dissipation paths within the rubbing solid. The objective of this paper is therefore to study the relation between the change in the HDC of a sliding solid and the transition in the mechanism of wear. It is shown that there exists an inverse correlation between the change in the HDC and the transition in the mechanism of wear. Moreover, it is also shown that a so-called ratio of residual heat (RRH, representing the ratio between the actual thermal load and the part of that load that is not dissipated by the solid) is a significant parameter that influences the magnitude and mechanism of wear. The findings are applied to explain the wear behavior of two tribo systems: a titanium (Ti-6Al-4V) sliding on itself and sliding on a steel (AISI M2) counterpart.     

Hole quality in longitudinal–torsional coupled ultrasonic vibration assisted drilling of carbon fiber reinforced plastics

Frontiers of Mechanical Engineering - Carbon fiber reinforced plastic (CFRP) composites are extremely attractive in the manufacturing of structural and functional components in the aircraft...