镍基单晶合金枝晶典型区域相成分最优化测算法

建立了用于测算镍基单晶高温合金枝晶典型区域相成分的最优化数学模型.根据电子探针对枝晶典型区域成分的测定结果,运用BFGS拟Newton法及CONSTR约束优化算法,可以计算枝晶各典型区域中γ和γ＇相成分.以镍基单晶合金CMSX-2和CMSX-4为对象,对优化测算结果进行了分析,证实了该方法的可行性.     

线控转向技术在装载机上的应用

介绍了装载机线控转向系统的工作原理，阐述了线控转向系统的主要优点和关键技术。该线控转向系统是通过微电子技术连接并控制转向系统的各个元件来代替传统的机械或液压连接，它取消了方向盘和转向车轮之间的机械或液压的连接，通过控制软件协调它们之间的运动关系，可以实现传动比、路感等参数的任意设置，具有传统转向系统所无法比拟的优点。     

电液比例控制技术在电铅堆垛中的应用

设计了堆垛装置电液比例位置闭环控制系统,并详细分析了系统的动静态特性,最后,利用基于MATLAB的SIMULINK工具箱对系统进行了模拟仿真,并针对系统的不稳定进行PID控制。     

Superplastic behavior of Al-Cu-Li based alloy

The superplastic behavior was studied in an Al-4Cu-ILi-0.4Mg-0.4Ag-0.1Zr alloy. The alloys were manufactured both by＂ a conventional rolling route and a thermo-mechanical treatment route. The superplastic properties were evaluated as a function of temperature, strain rate, and processing history. Prior to thermo-mechanical processing, the alloys have elevated-temperature ductilities of 94% to 130%, strain rate sensitivities of about 0.25, and activation energies corresponding to lattice diffusion. After thermo-mechanical processing, the alloys have ductilities of 200% to 630%, strain rate sensitivity of about 0.42, and activation energies corresponding to grain boundary diffusion or a mixture of grain boundary diffusion and lattice diffusion. Skipping rapid recrystallization annealing can supply a higher value of elongation-to-failure.     

表面处理对球墨铸铁接触疲劳性能的影响

本文研究了激光微熔处理和高频感应加热淬火对球墨铸铁表面组织、接触疲劳强度和接触疲劳破坏过程的影响。结果表明,激光处理和高频淬火均可提高球铁的接触疲劳强度,但其接触疲劳破坏过程和形式却不同,前者是由于硬化层与基体间裂纹扩展造成大块深层剥落,后者则是表层裂纹在油楔作用下造成小块浅层脱落。     

Ni—Ti合金中双程形状记忆速动相变的研究

利用应力对双程形状记忆合金中相变驱动力的制约作用,在Ni-Ti合金中实现了不需附加机构的速动相变和速动双程形状记忆效应。     

气动机械手的应用现状及发展前景

随着工业机械化和自动化的发展以及气动技术自身的一些优点,气动机械手已经广泛应用在生产自动化的各个行业.本文就气动机械手的应用现状和发展前景作了简单概述.     

Surface nanocrystallization of commercial pure titanium by shot peening

The surface nanostructures of commercial pure titanium was realized by the modified shot peening equipment commonly used in industry through the special treatment process. The results show that high-energy-shot-peening(HESP) commonly used to prepare nanostructured surface layers can be achieved by the increase of pill size, pill speed, and treatment time in the commercial shot peening equipment. XRD, SEM and TEM were used to characterize the surface layer microstructure of treated specimens. The analytic results show that the main deformation mode of commercial pure Ti is twinning. At the beginning of deformation, the dislocations are formed and twins occur within or on plane, then twins in intersection plane appear, and at last the twin characteristics disappear in the surface layer after longer treatment time. The deformation layer depth increases with treatment time in a certain period when the pill size and speed are unchanged. And in the severe plastic deformation (SPD) layer in which the twins are not identified easily by using SEM, the nanocrystalline microstructures are found under TEM. The finest grain size in the surface layer is about 40 nm, and the depth of nanostructured layers is over 60 μm. The microhardness of the nanostructured surface layers is enhanced significantly after shot peening compared with that of the initial simple.     

Sc、Zr对Al-Zn-Mg-Cu合金组织与性能的影响

制备了成分Al-5．8Zn-2．5Mg-1．6Cu-0．2Cr和Al-5．8Zn．2．5Mg-1．6Cu-0．2Cr-0．23Sc-0．12Zr的两种合金。通过金相显微镜及电镜观察、力学性能及腐蚀性能测试，分析了两种合金不同处理状态的显微组织及其不同状态下的力学性能和腐蚀性能。结果表明，添加Sc、Zr能显著细化合金的铸态组织，对合金的力学性能及腐蚀性能也起到极大的提高作用。添加Sc、Zr的2#合金与1#合金相比较，经T6处理后，前者的抗拉强度提高110N／mm^2，屈服强度提高91N／mm^2，伸长率也略有提高。     

Nd-Fe-B三元系相图的研究 Ⅰ.室温等温截面

观察了Nd-Fe-B三元合金铸态与均匀化处理后的金相组织,并进行了微区成分分析和物相鉴定。确定了Nd-Fe-B成分三角在室温下的各个平衡相区,绘制了该三元系在室温下的等温截面相图。