双联齿轮的精密闭式模锻工艺

介绍了双联齿轮精密闭式模锻工艺。精密闭式模锻与普通闭式模锻相比,可节约原材料、降低能耗、提高锻件精度和质量、减少机加工工时、提高劳动生产率。     

Co-Cr-Mo人工关节的精密锻造技术

Co-Cr-Mo合金是一种耐腐蚀性能很好的可植入人体的金属材料.根据人工关节的技术条件要求,确定了其精密模锻的工艺方案.在16000 kN曲柄压力机上利用机械压力机恒载荷精锻方法成功地实现了Co-Cr-Mo合金人工关节的精密锻造,经试验验证,采用机械压力机恒载荷精密模锻技术生产的锻件尺寸精度高、表面粗糙度低、锻造流线不外露,符合YY0117.3-93与ISO 5832-4：1996要求.     

直齿圆柱齿轮冷精锻实用化工艺研究

以实用化为目标,对１５＾＃钢、４５＾＃钢、２０ＣｒＭｎＴｉ直齿圆柱齿轮冷精锻工艺进行系统研究,提出了闭式镦挤－约束孔分流两步成形实用化工艺方案和基于变位理论和齿形模修正设计方法。     

铝合金MIG+激光复合焊接工艺研究

研究轻量化轿车用3A21铝合金M IG 激光复合焊接工艺,探讨工艺参数对焊缝成型的影响规律及激光与电弧的复合作用。试验结果表明,采用M IG 激光复合焊接工艺可以显著提高熔深和焊速,达到采用小功率激光焊机实现铝合金的激光焊接。在比较宽的工艺参数范围内M IG YAG激光复合焊接铝合金具有焊缝成型美观等优点,熔深和焊速均显著提高,大大提高生产率。     

铝合金薄壁零件高速加工关键技术的研究

HSM(High Speed Machining)是20世纪数控技术之后的又一次革命性的技术发展,它的基本特征是切削速度高(为常规切削速度的5～10倍),进给速度快(40～180m/min),加减速度大(1～2g)。从铝合金薄壁零件加工角度出发,对高速加工的一些关键技术进行了研究。     

铝合金铸件机箱四孔定位加工工艺方法研究

铸造铝合金材料因其良好的抗腐蚀性、流动性和切削加工性能,适合铸造薄壁、形状复杂和强度高的机箱等各类零件。根据实际生产过程中某薄壁类铸件机箱加工中易变形的问题,进行工艺流程改进,总结出铸件机箱的典型加工工艺方法,提高了产品质量和生产效率。     

铝合金表面激光沉积Al0.8FeCoNiCrCux高熵合金组织与耐蚀性能

为增强5XXX系铝合金表面的耐蚀性能,利用脉冲激光沉积技术制备了Al0.8FeCoNiCrCux高熵合金(HEA)涂层。利用XRD,SEM和电化学工作站分析了Al0.8FeCoNiCrCux高熵合金的相结构、微观组织和耐腐蚀性能。结果表明随着Cu含量增加,合金的相结构由BCC1和BCC2相转变为BCC1,BCC2和FCC相;当=0时,Al0.8FeCoNiCrCux涂层沿晶间出现裂纹,x=0.25时,涂层裂纹消失,并且在晶间出现了浅色组织,随着x增加,浅色组织由点状分布转变为连续生长;Al0.8FeCoNiCrCux(x=0.25,0.5,0.75,1.0)高熵合金涂层耐蚀性随Cu增加而降低,Al0.8FeCoNiCrCu0.25的腐蚀电流密为7.94×10^-8 A/cm^2,仅为基材的0.17%,腐蚀形式为点蚀,当x增加至1时,腐蚀电流密度增至8.21×10^-7 A/cm^2,为基材的1.99%,腐蚀形式转变为晶间腐蚀,但仍优于基材。显然,当0.25≤x≤1时,采用Al0.8FeCoNiCrCux涂层可显著改善铝合金的耐腐蚀性能。同时,其具有的高熵效应可抑制涂层中由基材的稀释行为引起的金属间化合物形成,解决了传统涂层材料应用在铝合金表面易产生裂纹的问题。     

汽轮机叶片精锻模具预补偿方法研究

针对汽轮机叶片加工精度要求高、精锻模具误差补偿难度大以及加工效率低等问题,以某型号汽轮机叶片为例,利用DEFORM-3D数值模拟软件分别对叶片精锻模具Z=5 mm叶根截面、Z=35 mm叶身截面以及Z=75 mm叶尖截面在不同锻压步数下的弹性变形进行了模拟分析,得出精锻模具型腔曲面变形规律。基于数值模拟结果,提出利用反向迭代补偿与黄金分割相结合的方法来修正精锻模具型腔。以该汽轮机叶片最大允许误差80μm为迭代目标,采用黄金分割法调整迭代区间,对各迭代点进行仿真,确定最优修正系数为0.94,最后得到满足终锻叶片精度要求的合理模具型腔,大大提高了模具设计质量与效率。     

锻造模具钢H13的热处理及氮碳共渗

研究了H13钢的热处理和氮碳共渗工艺,指出了H13钢适宜的热处理工艺为1030％淬火＋600％回火,然后再580％氮碳共渗4．5h。表面硬度可达900HV,渗氮层深0．2mm。采用H13钢的锻造模具在应用新工艺后,其寿命可提高1倍。     

2A70铝合金转子等温闭塞式锻造工艺研究

2A70铝合金转子是导弹发动机上重要的受力构件,对组织性能的要求很高。采用等温闭塞式锻造的方法生产转子锻件。为了使成形后的锻件顺利出模,采用了组合式凹模的结构。等温成形时,进行了大量的试验研究加热温度对成形过程的影响,最终确定模具和坯料的加热温度均为435 ℃。经检测,采用所设计的工艺方案生产的转子锻件的尺寸精度及组织性能均符合设计要求,成功地解决了切削加工的转子力学性能差、不能满足使用要求的问题。     

基于虚拟样机技术的冷锻压力机平衡缸设计

针对冷锻压力机的结构特点,设计了与滑块部件相关联的平衡缸部件。基于虚拟样机技术,对平衡缸部件的多种布置方案、不同摩擦条件和不同的平衡载荷等工况进行了分析与仿真。根据仿真结果得到了作用不同平衡载荷所需的驱动转矩,以及平衡载荷对滑块位置精度的影响,给出了平衡缸部件的设计和平衡载荷的选择依据。以此设计的压力机可提高滑块的运动平稳性和整机的工作可靠性。     

曲面铝合金锤击平整技术研究

以曲面铝合金为例,利用工业机器人锤击的方式对曲面类零件表面进行平整,并探究各锤击工艺参数对其表面的粗糙度、硬度及表面形貌的影响.将锤击装置装夹到工业机器人上,控制工业机器人以矩形光栅式运动路径对曲面铝合金表面进行锤击加工,并对锤击后表面的粗糙度、硬度及表面形貌进行测量观察.结果表明:经锤击加工后的铝合金表面粗糙度可达0...     

精密复合加工技术

首先阐述了复合加工技术的含义,提出广义复合加工技术的观点,特别是精密复合加工技术的概念.然后论述了精密复合加工技术在制造技术发展中的作用和创新意义,认为它是解决制造技术中工艺难题的重要手段,是在制造技术创新中求发展的新兴视野,是提升制造技术核心竞争力的有效途径.继而阐述了复合加工的类型,介绍了四种精密复合加工技术,即复合结合剂金刚石微粉砂轮超精密磨削技术、精密砂带振动磨削和研抛技术、精密车铣加工技术和化学机械抛光技术等,最后阐述了复合加工的应用和发展,以及当前应重视的问题.     

铝合金地铁车辆系统动力学特性仿真

地铁车辆系统要求具有良好的动力特性。运用多体系统动力学分析软件ADAMS/Rail建立了铝合金A型地铁动车系统动力学分析模型,进行了稳定性、平稳性和曲线通过能力仿真计算,依据相关标准比较全面地分析其动力学特性。结果表明,该车蛇行运动临界速度远大于车辆设计速度,并且其平稳性和曲线通过能力良好,可满足运行要求。     

Laser vision sensing based on adaptive welding for aluminum alloy

A laser vision sensing based on the adaptive tungsten inert gas (TIG) welding system for large-scale aluminum alloy components was established to fit various weld groove conditions. A new type of laser vision sensor was used to precisely measure the weld groove. The joint geometry data, such as the bevel angle, the gap, the area, and the mismatch, etc., aided in assembling large-scale aerospace components before welding. They were also applied for automatic seam tracking, such as automatic torch transverse alignment and torch height adjustment in welding. An adaptive welding process was realized by automatically adjusting the wire feeding speed and the welding current according to the groove conditions. The process results in a good weld formation and high welding quality, which meet the requirements of related standards. Translated from Journal of Beijing University of Technology, 2006, 32(8): 714–718 [译自: 北京工业大学学报]     

新刀具在汽车铝合金件加工中的应用

用PCD刀具加工汽车用铝合金件,能克服铝合金中硬质点对刀尖的破坏并最大可能地消除积屑瘤．用其加工能获得满意效果．且精度稳定。     

Analysis and Optimization on Factors Affecting Forming Quality of Half Axle Gears Warm Precision Forging

Half axle gears is produced by precision forging popularly because of the advantages in minimum machining allowances, lower material consumption and good service properties. But the forming quality of precision forging is difficult to control. Many simulations and analysis of precision forging process were taken by previous researchers. But no concrete method is proposed to evaluate and optimize the forming quality of half axel gears. The primary purpose of this work is improving the forming quality of half axel gears by analyzing and optimizing the affected factors of forming quality. The enclosed-die warm forging process of half axle gears was developed, and a new type of die-set used on double action hydraulic press was brought forward. The main influential factors of precision forming quality were analyzed after the forming process had been simulated by using finite element method(FEM). These factors include die structure, web thickness and web position. A method used to evaluate the forming quality was established, which investigated the maximal forming load, the metal filling rate and the material damage factor. The FEM simulations of half axle gears precision forging were evaluated by this method. The results show that the best forming quality can be achieved when the punches were added with bosses, the web located at the middle plant of the gear, and the web thickness was 30 percent of the inner hole diameter. Verification experiments taking the above optimized parameters were performed on a 7.8 MN double action hydraulic press. The trial products were formed well. And their geometric precision meets the demand. The verification result shows that the optimization of the influential factors, according to the simulations and the evaluation method, can improve the forming quality. The new structure of precision forging die-set and the new evaluation method guarantee a high forming quality of half axel gears.     

Parameter prediction in laser bending of aluminum alloy sheet

Based on the basic platform of BP neural networks, a BP network model is established to predict the bending angle in the laser bending process of an aluminum alloy sheet (1–2 mm in thickness) and to optimize laser bending parameters for bending control. The sample experimental data is used to train the BP network. The nonlinear regularities of sample data are fitted through the trained BP network; the predicted results include laser bending angles and parameters. Experimental results indicate that the prediction allowance is controlled less than 5%–8% and can provide a theoretical and experimental basis for industry purpose. __________ Translated from Optics and Precision Engineering, 2007, 15(6): 915–921 [译自: 光学精密工程     

铝合金轮毂的结构优化及试验分析

针对铝合金轮毂有限元分析模型中的应力集中和强度富余情况,利用ANSYS软件对其进行结构优化,使其应力分布更加合理,达到了提高材料的利用率和减轻自重的目的.优化后的轮毂通过了弯曲疲劳试验、径向疲劳试验和冲击试验,且试验结果与有限元分析结果基本吻合,从而论证了该轮毂研发途径的可行性.     

提高热锻模具使用寿命的有效途径

正火预处理可以细化原始组织和碳化物 ,可使 5Cr Mn Mo钢在临界温度加热淬火 ,提高其强韧性 ,减少脆裂现象发生。经生产验证 ,正火预处理是提高 5Cr Mn Mo钢热锻模具使用寿命的有效途径之一