硬铝拉杆管子表面划伤的电刷镀修复

研究了电刷镀技术在飞机铝合金零件表面划伤修复中的应用，提出了电刷镀修复铝合金件表面划伤的工艺流程及条件。     

电刷镀快速修复飞机硬铝合金构件表面划伤

研究了电刷镀技术在飞机铝合金零部件表面局部划伤修复中的应用 ,提出了电刷镀快速修复的工艺流程及工艺参数范围。     

镁合金制飞机零部件的电刷镀修复工节

研究了电刷镀技术在镁合金制飞机零部件表面划伤修复中的应用，提出了电刷镀修复镁合金的工艺流程及条件。     

镁合金制飞机零部件的电刷镀修复工艺

研究了电刷镀技术在镁合金制飞机零部件表面划伤修复中的应用，提出了电刷镀修复镁合金件的工艺流程及条件。     

纳米电刷镀技术修复飞机30CrMnSiA钢旋转体小零件

为解决类似飞机30CrMnSiA钢旋转体小零件镀铬修复中的氢脆、工艺复杂、成本高等难题,开展了电刷镀技术修复该类零件的可行性研究。初步探讨了利用n-Al2O3／Ni复合镀液对其进行电刷镀修复的工艺流程及条件,并对修复层的硬度、结合力、耐磨性进行了测定试验。结果表明：利用纳米电刷镀技术修复飞机30CrMnSiA钢旋转体小零件,其镀层质量完全满足使用要求,具有较好的推广价值。     

感应熔涂技术与电刷镀结合修复轴类零件

轴类零件表面经常有划伤、凹坑、沟槽等由于疲劳磨损而产生的问题,必须对其进行修复.而过去常用的单一的电刷镀技术,有时已不能满足其需要.为此,介绍了一种将高效快速感应熔涂技术与电刷镀技术相结合修复轴类零件的新工艺.研究和试验证明,该工艺具有高效快速、操作简单、可行性强等优点,值得深入研究和推广.     

飞机机翼主梁的电刷镀工艺

１前言电刷镀是一项机械零部件修复技术，具有设备简单、工艺灵活、镀速快、镀种多、结合强度高、污染小、一般不需机械加工等特点。精密零件的局部磨损、贵重零件加工超差等使用电刷镀技术进行修复时，经济效果显著，尤其是对飞机零部件的野外战伤抢修具有突出的实用价值...     

襟翼作动筒活塞的电刷镀修复工艺

为解决飞机襟翼作动筒磨损失效活塞的修复问题,开展了电刷镀镍-钨修复镀层的研究.通过对飞机襟翼作动筒活塞失效原因的分析,提出了修复该零件的新工艺.采用电刷镀特殊镍--Ni-W镀层体系,提高了镀层与基体、镀层与工作层的结合力.当镀层厚度为28 μm时,镀层硬度达到705 HV;网格剥离试验表明,镀层无脱落,附着力良好;弯曲试验表明,镀层无脱落;杯突高度为5.1 mm;镀层磨损量为0.118 mg/次,与基体(0.119 mg/次)耐磨损性相当.试验表明,通过这种工艺,可以获得满足修复磨损活塞要求的镀层.     

发动机连杆轴承座内孔的电沉积修复技术

连杆轴承损坏后采用手工电刷镀修复存在大头轴承座孔及镀层厚度沿周向不均、人工因素影响大、劳动强度大、操作环境差等缺点。为此,采用一种流镀融合电刷镀的电沉积技术修复斯太尔发动机连杆大头轴承座孔。利用SEM、XRD、显微硬度计等考察了镀层的组织结构和性能,并与传统手工电刷镀修复连杆工艺进行了对比。结果表明:该技术制备的镀层均匀、致密、孔隙率低,晶粒尺寸小,镀层硬度高,平均约为590.4 HV,比手工刷镀件的相应值479.4 HV高111.0 HV;采用该技术可以在35 min内一次镀覆6件连杆,手工电刷镀修复单件连杆需耗时约1 h,效率大幅提高;该技术过程工艺参数可以有效控制,可实现自动化并用于零件再制造。     

自动化n-SiC/Ni复合电刷镀层的高温摩擦性能研究

采用自主研制的自动化电刷镀技术制得n-SiC/Ni复合电刷镀镀层.对比研究了手动与自动复合电刷镀镀层的组织与摩擦磨损性能.相对于手动电刷镀镀层,自动化镀层表面形貌更加均匀细化,组织更加致密,显微硬度更高.高温滑动摩擦磨损实验表明:相对于手动电刷镀镀层,自动化镀层拥有更好的耐磨性能.     

飞机铝合金深锥型面零件多道次充液拉深技术

目的随着新一代飞机在隐身和战斗性能方面的提高,飞机钣金零件的复杂程度和制造精度要求也越来越高。对于深型腔复杂型面零件,充液拉深是一种有效的精密制造方法。方法针对难成形、复杂型面的某型飞机铝合金深锥零件,利用理论分析、有限元模拟和工艺试验相结合的方法,设计了多道次充液拉深技术方案,并建立有限元分析模型。基于等裕量函数法和零件锥面特征,分配并优化了不同道次的材料变形量。结果对多道次充液拉深成形过程中出现的起皱和破裂的失效形式进行了研究,分析了预成形高度,液室压力和压边力等关键工艺参数对零件成形质量的影响,获得了优化的预成形高度和液室压力加载轨迹。结论结果表明,提出的多道次充液成形技术能够实现复杂型面,大拉深比的铝合金零件的整体精确成形,采用优化的工艺参数能够成形出壁厚均匀,表面质量好,锥面精度高的零件。     

Investigation into hydromechanical deep drawing of aluminum alloy—Complicated components in aircraft manufacturing

An optimization is presented of the blank shape and the effect of the pressure in the die cavity on the formed parts by using a typical aluminum alloy used in aircraft manufacturing. By means of both numerical simulation and experiment, using two typical parts in aircraft, the forming processes in hydromechanical deep drawing are discussed and the key process parameters are optimized. The experimental results keep reasonable agreement with the numerical one.     

新型航空T-31钛合金导管连接件在模拟服役环境中的抗腐蚀性能研究

使用自行研制的航空导管连接件腐蚀试验系统,研究了新型航空T-31钛合金导管连接件在模拟服役环境中的气密性、油压气密性以及应力腐蚀、表面腐蚀等综合性能.对这种钛合金导管连接件在高温盐水溶液浸泡与烘烤循环条件下的表面腐蚀及应力腐蚀行为进行了评价;初步探讨了在模拟服役环境中,这种钛合金发生腐蚀的机理.并比较研究了导管材料1Cr18Ni9Ti与连接件钛合金在6%NaCl水溶液中的电偶腐蚀敏感性.研究发现,T-31钛合金导管连接件在模拟服役环境中只在应力集中处发生轻微孔蚀,在试验应力水平下,无应力腐蚀倾向,具有良好的耐蚀性能;并证明,腐蚀介质通过钛合金阳极化膜层小孔渗入基体对基体造成轻微腐蚀,试验应力水平未造成孔蚀发生处裂纹形核;电偶腐蚀试验进一步说明1Cr18Ni9Ti / T-31电偶对有很小的电偶腐蚀电流,用它们制备的导管及导管连接件能安全地进行偶接.     

A review on selective laser sintering/melting (SLS/SLM) of aluminium alloy powders: Processing,microstructure, and properties

Manufacturing businesses aiming to deliver their new customised products more quickly and gain more consumer markets for their products will increasingly employ selective laser sintering/melting (SLS/SLM) for fabricating high quality, low cost, repeatable, and reliable aluminium alloy powdered parts for automotive, aerospace, and aircraft applications. However, aluminium powder is known to be uniquely bedevilled with the tenacious surface oxide film which is difficult to avoid during SLS/SLM processing. The tenacity of the surface oxide film inhibits metallurgical bonding across the layers during SLS/SLM processing and this consequently leads to initiation of spheroidisation by Marangoni convection. Due to the paucity of publications on SLS/SLM processing of aluminium alloy powders, we review the current state of research and progress from different perspectives of the SLS/SLM, powder metallurgy (P/M) sintering, and pulsed electric current sintering (PECS) of ferrous, non-ferrous alloys, and composite powders as well as laser welding of aluminium alloys in order to provide a basis for follow-on-research that leads to the development of high productivity, SLS/SLM processing of aluminium alloy powders. Moreover, both P/M sintering and PECS of aluminium alloys are evaluated and related to the SLS process with a view to gaining useful insights especially in the aspects of liquid phase sintering (LPS) of aluminium alloys; application of LPS to SLS process; alloying effect in disrupting the surface oxide film of aluminium alloys; and designing of aluminium alloy suitable for the SLS/SLM process. Thereafter, SLS/SLM parameters, powder properties, and different types of lasers with their effects on the processing and densification of aluminium alloys are considered. The microstructure and metallurgical defects associated with SLS/SLM processed parts are also elucidated by highlighting the mechanism of their formation, the main influencing factors, and the remedial measures. Mechanical properties such as hardness, tensile, and fatigue strength of SLS/SLM processed parts are reported. The final part of this paper summarises findings from this review and outlines the trend for future research in the SLS/SLM processing of aluminium alloy powders.     

Ni-based superalloy surface alloying by double-glow plasma surface alloying technique

The double-glow surface alloying technique, also called the Xu-Tec/Xu-Loy process, is a novel technique in the field of surface alloying. This technique allows alloy layers with unique physical, chemical and mechanical properties, such as nickel-based alloy layers, stainless-steel layers and age-hardened surface high-speed steel layers to be formed at the surface of treated metallic materials. In this paper, recent research of the application of the double-glow plasma surface alloying technique in the formation of corrosion resistance alloy layers is briefly reviewed. The results of a study of Ni-Cr-Mo-Nb and Ni-Cr-Mo-Cu corrosion-resistant alloying layers as well as composite alloying layers with an electric brush plating Ni interlayer are reported.     

感应熔覆技术研究现状及发展

机械零件长期在高温、潮湿以及交变载荷等恶劣环境下工作,会导致机械设备出现可靠性降低和服役寿命缩短等问题。因此,对零件表面性能提出了高耐磨性和高耐腐蚀性等严苛要求。在此背景下,感应熔覆技术作为绿色表面改性工艺,因其成本低、效率高、热影响区小及熔覆质量好等特点而被广泛应用于机械零件表面强化领域。首先,简述了感应熔覆技术的工作原理和特点,重点探讨了自熔性合金粉末和添加陶瓷及稀土元素合金粉末的应用效果和潜在优势;其次,介绍了感应熔覆技术的工艺流程,分析了预制涂层、保护套筒以及其他强化工艺对感应熔覆涂层性能和质量的影响,指出敏感性参数是影响感应熔覆涂层成形和传热的重要因素;最后,概括了感应熔覆数值模拟方法的发展现状和存在的问题,并针对感应熔覆成形过程和传热机制的发展提出了相关建议。在此基础上,对感应熔覆增材制造过程中的关键科学问题和技术难题进行了展望并提出了未来的研究方向。通过研究新材料及采用新型数值模拟技术,为优化工艺参数和开发新型涂层提供更加精确的指导。     

Fracture analysis of turbine disks and computational–experimental background of the operational decisions

In this paper, fatigue crack growth under operation conditions for rotating disks of aircraft gas turbine engines is analyzed. Initiation and growth of surface cracks for compressor disks made from two-phase titanium alloy has occurred in a disk and blade attachment. Damage accumulation and growth for turbine disks made from steel took place on the inner surface of hole in a hub of wheel. Suggested approach of simulation modeling is used for an analysis and prevention of operation failures of engine rotating components. In the approach described, finite-element models (FEMs) in two and three dimensions were applied to the study of stress–strain state and stress intensity factors for the basic configurations of compressor and turbine disks and their operational damage. Proposed design modifications and repair technologies to existing in-service aircraft gas-turbine engine rotating components are analyzed and substantiated on a static strength and fatigue life basis.     

β21S超高强钛合金性能试验研究

β21S(名义成分Ti-15Mo-3Al-2.7Nb-0.2Si)钛合金是Timet公司针对美国航空航天飞机计划NASP对抗氧化金属及复合材料基体的需求而研制的一种亚稳定β型钛合金,该合金具有优异的冷热加工性能、深的淬透性、抗蠕变性能、高的抗氧化性能和良好的抗腐蚀性能,可用于制作有温度要求的飞机结构件或发动机部件紧固件和液压管材、钣金件等,已经用于制造波音777飞机发动机舱导风罩等部件。β21S合金作为一种典型的亚稳定的β型钛合金,通过适当的工艺热处理后,可获得1 300 MPa以上超高抗拉强度及不小于6%的延伸率,为了全面了解并掌握高强热处理工艺处理后的β21S钛合金性能,我们对β21S钛合金进行了全面性能试验研究。     

高强度ZL205A铝合金飞机挂架铸造工艺

根据某飞机挂架在结构特点和使用要求,结合高强度铝合金ZL250A的工艺特性,分析和讨论ZL205A合金飞机挂架的砂型铸和工艺。结果表明：立式浇注位置设计,可保证挂架整体性能、成分均匀合理：帖面冷铁式半金属型激冷,配以合理冒口补缩,保证铸位组织致密,性能优良; 直浇道、横浇道和内浇道截面比为1：3：5,并配合带缓冲结构的合理缝隙,可保证型腔内液面上升平稳,减少铸件内部二次氧化夹杂和混入性气体;砂芯整体设计,可保证挂架尺寸的稳定。     

电刷镀-激光加工法制备耦合结构及复合特性研究

通过电刷镀-激光加工法在铝合金表面制备出特殊的复合结构,获得具有低黏附、耐腐蚀特性的超疏水表面,其对水的静态接触角达到155.1°,滚动角小于5.6°。利用扫描电子显微镜(SEM)、光学显微镜、接触角测量仪(OCA15Pro)和X射线衍射仪(XRD)表征表面的形貌结构、润湿特性和物相组成,并通过腐蚀性实验对表面的耐腐蚀性能进行研究。结果表明:制备表面是一种带有孔洞的沟槽与菜花状的凸包簇形成的复合结构,并且各凹槽与凸包结构均为定尺寸分布。电刷镀处理使表面物相组成相对于基体表面发生明显变化,进一步的激光加工使峰值强度增强,材料组织发生细化现象;耦合方法所制备表面的耐腐蚀性也得到改善。