变速器前壳体加工中心专用夹具设计

为实现变速箱前壳体一次装夹同时进行钻、铣、镗加工的要求,设计了一套加工中心用变速箱前壳体快速装夹的液压自动专用夹具。针对变速箱前壳体的结构采用"一面两销"定位方式,设计了自定心机构,并详细阐述了机构原理,保证定位精准可靠。夹具采用液压夹紧,计算了切削力和夹紧力,选取了夹具油缸并设计了相应的液压系统。实践证明:该夹紧结构简单,操作方便,避免了基准的转换,保证了加工精度,提高了加工效率。     

变速箱体双工位钻镗专用夹具设计

针对变速箱体被加工孔系多,同轴度要求高,跨距大,在传统工艺上加工过程中需要多次装夹和更换刀具,在卧式镗铣加工中心上加工成本高的情况,设计了一种可以在立式加工中心上对变速箱体进行快速加工的双工位旋转专用夹具。阐述了该夹具的结构特点及工作原理,通过对变速箱体的加工工艺分析,采用完全定位的方案,并对定位误差进行分析和控制,采用液压夹紧和翻转,并计算切削力和夹紧力,设计了相应的液压系统。该夹具可以使工件在立式加工中心上实现一次装夹完成上下两面的加工,满足了企业生产要求,提高了生产效率和经济效益。     

PCB电路印刷基板卡位数控加工夹具设计

对非金属PCB电路印刷基板卡位的加工工艺进行了分析,设计一副专用夹具,解决了工件装夹定位问题,并在加工使用过程中根据实际情况进行了夹具的优化改进,使夹具能简单、快捷、安全地安装在机床上,提高了夹具的稳定性,保证了工件的加工精度,节省了夹具制造成本。     

双工位刚性钻镗定位销孔组合机床

所述机床一次装夹工件并采用刚性钻镗工艺，完成工件定位销孔的加工。在第Ⅰ工位采用刚性短钻头（无钻模板）加工方案，使机床在结构上在第Ⅱ工位进行刚性镗削成为可能。另外，在第Ⅱ工位采用一个先固定，而另一个可作横向微量调整的高精度镗头，从而保证达到孔距公差要求。     

铝合金曲面薄壁件柔性工装夹具的加工性能研究

针对开发的铝合金薄壁曲面柔性夹具系统,设计柔性工装夹具的可行性对比试验.在对曲面薄壁试样工件的铣削加工中,分别使用柔性夹具与原来的代木夹具作为支承,使用同样的铣削参数进行加工.分析两种装夹方法的装夹效率及加工工件的表面质量,并利用Hyper Works的模态分析证明柔性夹具系统有良好的减振功能.     

数控铣床加工轮轴零件的专用夹具设计

在批量机械零件加工中,为了提高零件的加工质量和生产效率,以及降低生产成本,通常会想方设法对一些通用夹具进行改装或者设计制造一些专用夹具,使工件在装夹时既快又稳,而在数控机床上加工工件时,这些改装过的通用家具和设计的专用夹具就更能充分发挥数控机床加工潜力,提高生产效率,保证加工精度,甚至扩大机床的使用范围。根据轮轴零件的工艺要求,设计了一套其在数控铣床上加工的专用夹具,实现了轮轴零件在数控铣床上优质、高效、多件同时加工,提高了生产效率和加工质量。     

转向架轴箱专用机床及夹具设计

对转向架轴箱的加工方案进行分析,设计钻孔专用机床。为了实现转架轴箱体一次装夹完成4-12 mm孔的加工,设计一套液压专用自动夹具。实践证明:该夹具结构简单,操作方便,加工过程中实现了对工件的快速定位装夹,提高了生产效率。     

轮辋数控加工工艺分析及其加工中心夹具设计

从工程实际情况出发,针对汽车轮辋工件数控加工装夹问题,分析轮辋数控加工工艺,采用加工面单位法矢量方法分析轮辋零件图纸,并考虑数控机床工序集中的特点,制定出合理可行的数控加工工艺方案。为解决轮辋工件在加工中心上的装夹问题,分析轮辋工件定位问题,采用气动控制夹紧方案,设计了一种加工中心夹具装置。该夹具结构简单、装夹方便,适用于轮辋、轮毂等同类工件的批量数控加工。     

一次安装完成两垂直孔镗削夹具设计

介绍了一种在普通镗床上一次安装工件可同时完成处在两个不同加工表面之间的两垂直孔镗削夹具的设计、制造过程及使用方法。     

胀力心轴的创新与运用

随着汽车变速齿轮的精度要求的不断提高,与其相应的制造工艺、工装也在不断创新。介绍了一款在磨齿加工工序中,利用账力心轴夹具夹紧行程小这一特征,对账力心轴夹具的弹簧套与刚性心轴的工作锥度进行了创新型的改进,使原来弹簧套工作时,撑紧工件内孔的弹性夹紧力沿内孔轴向逐渐变化而趋于相等。由生产实践证实:使用该夹具进行工件定位,其定心精度大大提高,保证了齿轮磨齿加工后的高精度;工件的装夹方便、快捷,提高了生产效率,并有利于工件装夹实现自动化。     

Effects of Post-weld Heat Treatment on Microstructure,Mechanical Properties and the Role of Weld Reinforcement in 2219 Aluminum Alloy TIG-Welded Joints

In as-welded state, each region of 2219 aluminum alloy TIG-welded joint shows diff erent microstructure and microhardness due to the diff erent welding heat cycles and the resulting evolution of second phases. After the post-weld heat treatment, both the amount and the size of the eutectic structure or θ phases decreased. Correspondingly, both the Cu content in α-Al matrix and the microhardness increased to a similar level in each region of the joint, and the tensile strength of the entire joint was greatly improved. Post-weld heat treatment played the role of solid solution strengthening and aging strengthening. After the post-weld heat treatment, the weld performance became similar to other regions, but weld reinforcements lost their reinforcing eff ect on the weld and their existence was more of an adverse eff ect. The joint without weld reinforcements after the post-weld heat treatment had the optimal tensile properties, and the specimens randomly crack in the weld zone.     

The First Phase of the SRIF Industrialized Base in ＂West Area＂ Has Been Put into Operation

After nearly two years＇ tense construction, the first phase of industrialized base of Shenyang Research Institute of Foundry （SRIF）, located at the Tiexi Casting and Forging Industrial Park in the west of Tiexi District, has now been completed and formally put into operation.     

Theoretical Analysis for the Motion and Temperature of Melt Droplets in Spray Degassing Process

The motion of melt droplets in spray degassing process was analyzed theoretically. The height of the treatment tank in spray degassing process could be determined by the results of theoretical calculation of motion of melt droplets. To know whether the melt droplets would solidify during spraying process, the balance temperature of melt droplets was also theoretically analyzed. Then proof experiments for theoretical results about temperature of melt droplets were carried. In comparison, the experimental results were nearly similar to the calculation results.     

Growth Kinetics of Single Inclusion Particle in Molten Melts

On the basis of the single-particle framework, a new theory on inclusion growth in metallurgical melts is developed to study the kinetics of inclusion growth on account of reaction and collision. The studies show that the early growth of inclusion depends on reaction growth and Brawnian motion collision, and where the former is decisive, the late growth depends on turbulence collision and Stokes＇ collision, and where the former is dominant; collision growth is very quick during the smelting process, lessened in the refining process, but nearly negligible in the continuous casting process.     

An Easy Way to Quantify the Adhesion Energy of Nanostructured Cu/X(X=Cr,Ta,Mo,Nb,Zr) Multilayer Films Adherent to Polyimide Substrates

An approach based on film buckling under simple uniaxial tensile testing was utilized in this paper to quantitatively estimate the interfacial energy of the nanostructured multilayer films(NMFs) adherent to flexible substrates. The interfacial energies of polyimide-supported NMFs are determined to be *5.0 J/m2 for Cu/Cr, *4.1 J/m2 for Cu/Ta,*2.8 J/m2 for Cu/Mo, *1.1 J/m2 for Cu/Nb, and *1.2 J/m2 for Cu/Zr NMFs. Furthermore, a linear relationship between the adhesion energy and the interfacial shear strength is clearly demonstrated for the Cu-based NMFs, which is highly indicative of the applicability and reliability of the modified models.     

High-Speed Friction Stir Welding of SiC_p/Al–Mg–Si–Cu Composite

A 17 vol% SiCp/Al–Mg–Si–Cu composite plate with a thickness of 3 mm was successfully friction stir welded(FSWed) at a very high welding speed of 2000 mm/min for the first time. Microstructural observation indicated that the coarsening of the precipitates was greatly inhibited in the heat-affected zone of the FSW joint at high welding speed, due to the significantly reduced peak temperature and duration at high temperature. Therefore, prominent enhancement of the hardness was achieved at the lowest hardness zone of the FSW joint at this high welding speed, which was similar to that of the nugget zone. Furthermore, the ultimate tensile strength of the joint was as high as 369 MPa, which was much higher than that obtained at low welding speed of 100 mm/min(298 MPa). This study provides an effective method to weld aluminum matrix composite with superior quality and high welding efficiency.     

新型的治疗阿尔茨海默氏症药物(1-二甲基磷酰基-2,2,2-三氯)-乙基-1-醇烟酸醋对体外神经细胞的作用

目的: 观察本实验室合成的一种治疗阿尔茨海默氏症(AD)的药物(1-二甲基磷酰基-2, 2, 2 -三氯)-乙基^-1-醇烟酸醋(NMF),对体外培养的皮层神经细胞活性的影响以及对海人藻酸(KA)所致的神经损伤的保护作用。方法: 采用体外培养皮层神经元的方法,解剖分离 15 d胚胎小鼠皮层神经细胞, 接种于 96孔板,48 h 后加药并培养 72 h,以 MIT 法 观察 NMF 对小鼠皮层神经细胞活性的影响;同时将接种于 24 孔板的细胞预先给予 NMF,d 3 时加或不加KA处理后,以台盼蓝染色鉴别并计数死、活细胞,可得出细胞的存活率。结果: NMF 明显促进胎鼠皮层神经元活性,其中 NMF1、0. 1、10nmol·L^-1促进神经元活性增殖率分别高达 34.7%、37.4%、36. 7%, NMF 明显促进正常胎鼠皮层神经元存活卒,与对照组比较,10nmol·L^-1 NMF 对皮层神经元的存活率分别提高 39.3%、73.5%。 NMF能显著 对抗 KA 所致的神经元损伤,与 KA 损伤组相比, NMF0.1、10、10nmol·L^-1对损伤皮层神经元的保护率分别为 77.30%、80.10%、84.15%。结论: NMF 明 显促进胎鼠皮层神经元的洁性、提高正常皮层神经元,的存活卒,并能有效地保护KA所致的神经元损伤,提示 NMF 是一种很有潜力的治疗 AD 的药物。     

A STUDY OF TEMPERATURE-DEPENDENT VALENCE BOND STRUCTURE OF TITANIUM

On the basis of energy and shape method for the determination of the valence bond (VB) structures of crystal, the valence bond structure of titanium is redetermined at room temperature and calculated in the whole temperature range of 0-1943K. The outer shell electronic distribution of Ti is e_c~(2.9907) · (s_c~(0.4980) d_c~(2.4927)) ef1.0093 in crystal. The temperature dependences of the VB structures of hcp and bcc phases are the same. The VB structures of hcp and bcc phases monotonically increase or decrease with the increase in temperature, but show discontinuous changes at the phase-transformation temperature 1155K.     

Structural Optimization of Electromagnetic Swirling Flow in Nozzle of Slab Continuous Casting

During the slab continuous casting process, the flow field of molten steel in the mold plays a decisive role in the quality of the slab. In this paper, electromagnetic swirling flow in nozzle technology is proposed to control the flow field in mold.This technology can drive molten steel to rotate inside the submerged entry nozzle by electromagnetic force, thereby controlling the flow field. This research shows that it can reduce the impact of molten steel on the bottom of nozzle and partly reduce the negative pressure at the upper part of nozzle outlet which is even eliminated by optimizing the structure and angle of nozzle. The area of heat flux of the mold wall becomes larger, and the crest value of heat flux gets lower than that without swirling in nozzle and any nozzle optimization. The meniscus fluctuates smoothly, and the flow velocity at the top surface is within a reasonable range. The temperature field distribution in the mold is uniform which was beneficial to the growth of equiaxed crystal and decreased element segregation.     

Effect of Rare Earth Doping on Impedance,Modulus and Conductivity Properties of Multiferroic Composites:0.5(BiLa_xFe_(1-x)O_3)–0.5(PbTiO_3)

The Lanthanum-doped bismuth ferrite–lead titanate compositions of 0.5(Bi LaxFe1-xO3)–0.5(Pb Ti O3)(x = 0.05,0.10,0.15,0.20)(BLxF1-x-PT) were prepared by mixed oxide method.Structural characterization was performed by X-ray diffraction and shows a tetragonal structure at room temperature.The lattice parameter c/a ratio decreases with increasing of La(x = 0.05–0.20) concentration of the composites.The effect of charge carrier/ion hopping mechanism,conductivity,relaxation process and impedance parameters was studied using an impedance analyzer in a wide frequency range(102–106Hz) at different temperatures.The nature of Nyquist plot confirms the presence of bulk effects only,and non-Debye type of relaxation processes occurs in the composites.The electrical modulus exhibits an important role of the hopping mechanism in the electrical transport process of the materials.The ac conductivity and dc conductivity of the materials were studied,and the activation energy found to be 0.81,0.77,0.76 and 0.74 e V for all compositions of x = 0.05–0.20 at different temperatures(200–300 °C).