CR法生成TiB2／Al复合材料制备工艺研究

在实验的基础上，分析CR法生成TiB2/Al复合材料的制备工艺的五个关键问题，得出相应的解决方法，制备出了颗粒分布均匀，组组致密，性能较理想的TiB2/Al复合材料，对复合材料制备工艺的实际应用具有重要意义。     

TiAl基高温自润滑材料的机械和磨损性能研究

以Ti44Al2Cr8Nb0.5B0.5Al2O3合金粉末为基体材料,添加固体润滑剂62%Ba F2-38%Ca F2共晶体,采用真空热压烧结技术制备抗磨减摩、耐高温、轻质的Ti44Al2Cr8Nb0.5B0.5Al2O3/(62%Ba F2-38%Ca F2)高温自润滑复合材料。研究在600℃高温下、相同接触压力和滑动速度的工况下,62%Ba F2-38%Ca F2共晶体含量对Ti44Al2Cr8Nb0.5B0.5Al2O3/(62%Ba F2-38%Ca F2)高温自润滑复合材料的摩擦磨损性能的影响以及室温工况下,对硬度、相对密度、抗拉强度、延伸率和冲击韧性的影响。结果表明:随着62%Ba F2-38%Ca F2含量增加,复合材料的相对密度逐渐减小,抗拉强度、冲击韧性、硬度以及延伸率均减小,摩擦系数逐渐减小,磨损率先降低后升高。当62%Ba F2-38%Ca F2体积分数为11%时复合材料的磨损率最低,摩擦系数较小,且其机械性能较好。     

干摩擦条件下Al_2O_3基复合材料的摩擦磨损特性

以用SiC、Ti(CN)和ZrO2颗粒增韧的三种Al2O3基复合材料为研究对象,利用销盘式摩擦磨损试验机研究了它们的摩擦磨损性能,通过扫描电子显微镜对其磨损形貌进行了观察和分析.结果表明:在本试验条件下,Al2O3基复合材料的耐磨性能与添加剂的种类有关,其耐磨性能好坏顺序为Al2O3/Ti(CN)、Al2O3/SiC、Al2O3/ZrO2;Al2Os/SiC复合材料的磨损机理主要为疲劳磨损和脆性断裂,Al2O3/ZrO2和A12O3/Ti(CN)复合材料的磨损机理主要为磨粒磨损.     

反应生成Al2O3颗粒增强铝基复合材料

采用电磁搅拌方法,向Al熔体中加入AlNH4(SO4)2,反应生成了Al2O3颗粒,成功制备了Al2O3/Al复合材料.采用此方法制备复合材料成本低、工艺简单.试验结果表明,生成的Al2O3颗粒小,均匀分布在Al基体上,具有显著的增强效果,复合材料的硬度远高于基体材料.     

AlN-TiB_2复相导电陶瓷的制备及性能研究

以微米Al N、微米Ti B2以及纳米Si C为主要原料,以微米Y2o3和微米Al2o3为添加剂,采用真空N2气氛保护热压烧结工艺制备了Al N-Ti B2复相导电陶瓷材料。测试和分析了烧结样品的相对密度、弯曲强度、硬度值以及导电性能。结果表明,当微米Al N添加量为55wt%,微米Ti B2为20wt%,纳米Si C为20wt%,微米Y2o3为3wt%以及微米Al2o3为2wt%时,且烧结温度为1880℃时,所制备的Al N-Ti B2复相导电陶瓷材料性能最佳,其相对密度为94.45%,弯曲强度为512.35MPa,洛氏硬度为104.25,电阻率值为1526μΩ.cm。     

Al-Ag-Cu-Ti反应扩散连接SiCp/2009Al复合材料的工艺研究

采用Al-Ag-Cu-Ti中间夹层,在真空条件下对SiCp/2009Al复合材料进行了反应扩散连接研究。通过正交试验设计得到了最佳的连接工艺为:连接温度550℃,保温时间60min,压力2×10-3MPa,Ti含量为3wt%。力学性能试验结果表明,采用该工艺得到的接头剪切强度可达120MPa。对连接区进行SEM、XRD和EMPA分析表明,连接区生成了Ag2Al、Al2Cu、Al3Ti、Al3Cu Ti金属间化合物,少量的金属间化合物能起到有效增强接头连接区的作用,和母材的力学性能相匹配,提高连接接头的综合性能。     

反应生成Al3Ti、Al2O3/Al复合材料的力学性能研究

讨论了不同的TiO2/Al摩尔比对Al-TiO2系热扩散反应法（XD）合成铝基复合材料的力学性能的影响。反应产物Al3Ti呈棒状，Al2O3呈细小颗粒状；随着TiO2/Al摩尔比的增加，增强相（Al3Ti、Al2O3）体积分数提高，材料的拉伸强度明显增强，伸长率逐渐减小。棒状物Al3Ti强底低，阻碍Al3Ti、Al2O3／Al的拉伸性能进一步提高。     

TiAl合金研究进展

Ti Al合金密度低且具有优异的高温性能、良好的阻燃能力以及抗氧化性,是未来航空航天领域重要的高温结构材料之一。文中分析了PIGA、EIGA、VIGA、PREP、PA等方法制备Ti Al合金粉末的工艺特点,阐述了热等静压、放电等离子烧结、反应烧结、粉末注射成形技术制备Ti Al合金的工艺,分析了制备Ti Al合金工艺所存在的问题对于TIAl合金实际应用的影响,讨论了提高Ti Al合金的高温抗氧化性及室温塑性的方法。     

原位反应结合热压烧结工艺制备Al_2O_3/Fe-28Al-5Cr复合材料的组织和性能

采用原位反应结合热压烧结工艺制备了Al2O3质量分数为10%和20%的Fe-28Al-5Cr基复合材料,研究了它们的物相、显微组织、力学性能,以及室温和200,400,600,800℃下的摩擦磨损性能,并与采用外加Al2O3方法制备的相同复合材料进行了对比。结果表明:原位合成Al2O3制备的复合材料由Fe3Al和Al2O3两相组成,Al2O3主要分布在晶界处;随着Al2O3含量的增多,复合材料的硬度逐渐增大,抗弯强度明显降低;当Al2O3质量分数为20%时,复合材料的耐磨性能得到了明显改善;与外加20%Al2O3制备的复合材料相比,原位合成Al2O3制备的复合材料具有较高的硬度和强度,在室温和200,800℃下的磨损率稍低。     

直接氧化法制备高韧性陶瓷基复合材料

介绍了直接氧化法制备 Al2 O3/Al复合材料的制备工艺 ,实验研究了无补韧材料的烧结工艺 ,对利用 Si C颗粒增强补韧陶瓷材料的烧结工艺进行了研究 ,并对烧结的材料进行了 X-射线衍射分析和光学显微镜观测。     

齿轮传动优化设计的MATLAB实现

本文给出了优化设计的方法及利用MATLAB优化工具箱进行优化设计的步骤；建立了二级齿轮传动的数学模型并给出了MATLAB的实现方法,优化效果良好。     

Investigating surface roughness of parts produced by SLS process

Selective laser sintering (SLS) has been recognized as one of the best rapid prototyping (RP) technique for producing solid models, directly from computer-aided design data by fussing together different layers with the help of laser light. Further, RP has traditionally been used for producing a solid model for visualization purpose and assessing kinematic functionality. So, the model is required to have superior mechanical integrity and surface quality for handling and model testing. This study investigates surface roughness (SR) of parts produced by SLS process. The empirical models have been purposed to predict the feasibility of different process parameters viz., laser power, scan spacing, bed temperature, hatch length, and scan count on SR. Further, these parameters have been optimized using face-centered central composite design with response surface methodology. The optimized parameters have been verified by conducting confirmation experiments.     

磷锗锌单晶生长装置的设计与优化

根据磷锗锌（ZnGeP2）晶体的生长特性,分析了ZnGeP2单晶生长对生长炉温场的要求。在两温区单晶生长炉的基础上,设计出适合ZnGeP2单晶生长的三温区管式生长炉,并对其温场进行了设计与优化。在经优化的温场中进行ZnGeP2单晶生长,获得了尺寸达20 mm×30 mm、外观完整的单晶体。     

A complementary-metal-oxide-semiconductor-field-effect-transistor-compatible atomic force microscopy tip fabrication process and integrated atomic force microscopy cantilevers fabricated with this process

A complementary-metal-oxide-semiconductor-field-effect-transistor-compatible process for the fabrication of atomic force microscopy cantilevers with integrated tips has been developed. For the first time, the tips are fabricated after the completion of the regular complementary metal-oxide-semiconductor-field-effect-transistor fabrication process sequence. On-chip circuit components, such as piezoresistive deflection sensors, deflection actuators, and amplifiers, are fabricated on the mirror-polished surface of the wafer, ensuring optimal performance. The tip fabrication process is based on anisotropic silicon etching at low temperature using a tetramethylammonium hydroxide solution. The anisotropic etching process has been optimized to ensure process controllability. Using the described process, complementary-metal-oxide-semiconductor-field-effect-transistor-based cantilevers with piezoresistive deflection sensors and integrated tips have been successfully fabricated. Force-distance curves and scanning images in constant-force mode have been recorded.     

液流悬浮加工的工艺参数研究

提出了一种液流悬浮研抛加工的新工艺方法,开发了基于三坐标数控铣床的液流悬浮研抛试验系统.通过分析研抛过程的影响因素,确定了以研抛液介质、磨料(SiC)浓度、研抛头转速和研抛时间作为试验考察对象,并对光学玻璃K9进行研抛加工正交试验.试验结果证明了利用液流悬浮纳米磨料的方法可以实现光学晶体材料的亚微米去除和超光滑表面加工,并给出了各影响因素的优选结果.     

Robotic fiber placement process analysis and optimization using response surface method

Unlike traditional materials, composites are carefully designed materials suitable for specific applications. Conventional methods of fabrication of composite structures have proven to be labor intensive and time-consuming. Robotic fiber placement is a composite fabrication technique that increases the flexibility of fiber placement process and allows for the fabrication of more complex structures. This study is aimed at analyzing and optimizing the robotic fiber placement process parameters. Many experiments have been conducted to analyze gas torch temperature, fiber laying head speed, and fiber compaction force and the process is optimized using response surface method.     

蒸燃联合循环机组主汽阀、中压再热阀的加工研究

介绍了蒸燃联合循环机组中材质为GH901的主汽阀杆和调节阀杆、汽封套筒等工件的工艺流程,对高温合金渗氮前后进行了机械加工试验,制作出专用的刀具,选出了最佳的切削参数。     

Process metallurgy design of aluminum alloy sheet rolling by using two-scale finite element analysis and optimization algorithm

Recently, the asymmetric rolling (ASR) process was applied to the aluminum alloy sheet generation to control the micro-crystal structure in order to improve the formability and the strength. Until now, many experimental and numerical studies of ASR process have been carried out, but these schemes have not enough capability to predict the texture evolution at the micro-scale and the sheet formability at the macro-scale. In this study, we develop a process metallurgy design code to analyze and optimize the sheet rolling process. At first, our dynamic-explicit crystallographic homogenized elasto/viscoplastic finite element (two-scale FE) code was applied to analyze ASR sheet deformation and optimized ASR process to generate a high formability sheet metal by employing the response surface method. A texture evolution of ASR sheet metal under an optimum process condition was compared with the experimental results, and the availability of our design code was confirmed. Next, an initial texture for the symmetrical warm rolling was optimized to generate a better formability sheet metal. Consequently, our two-scale FE code combined with the optimization algorithm was verified as a comprehensive tool in the process metallurgy design to predict plastic induced texture evolutions and optimize a rolling process and an initial texture for a high formability sheet generation.     

汽车发电机磁极精锻成形三维有限元模拟和工艺优化

简述了汽车发电机磁极几种典型成形工艺。基于Abaqus通用有限元软件,应用三维刚粘塑性有限元显式算法对磁极精锻成形过程进行了模拟分析,得出了变形中材料的流动状态和等效塑性应变分布规律。根据有限元模拟分析结果对磁极精锻成形工艺参数、模具结构进行了优化设计,并进行了磁极精锻成形工艺试验。试验验证了有限元模拟分析结果,并精锻成形出合格的汽车发电机磁极产品。     

磷酸铁锂电池组的动态诊断与均衡策略研究

针对混合动力汽车单体电池性能的不一致性造成的不利影响，研究了动态过程中的电池特性规律，并设计了相应的均衡策略，进而进行了试验验证。该策略以高速采样系统为基础，在动态过程中对电池组各单体电压进行实时精确采集并分析处理，再通过大量试验总结出的电池特性规律，动态诊断出需要均衡的单体，并进行均衡。试验结果表明，均衡策略快速准确，效果显著，使电池组使用特性得到了很好的优化。