薄片塑料齿轮机械加工技术

本文分析了高精度尼龙扇形片齿轮零件常规机加工中存在的问题，通过采用合理的定位、夹持方法和与之相适应的加工工艺参数，解决了扇形片齿轮在加工过程中的变形和齿轮加工精度的问题。     

典型薄壁零件的车削工装设计

薄壁结构件因其特有的重量轻、节约材料、结构紧凑等特性被越来越广泛地应用于航空、航天、橡塑等领域,但其薄壁结构刚性较低、加工工艺性差,极易产生变形,本文针对典型薄壁零件装夹变形问题,总结出了一些实际可行的工装夹具设计方法,实践证明,这些工装能够有效地解决薄壁零件变形问题。     

飞机结构梁多轴铣削加工程序与工艺优化研究

为解决飞机结构梁铣削加工过程中容易产生变形的问题。针对飞机结构梁类的薄壁腔体难加工零件进行了加工工艺分析和流程设计,此类零件的毛坯残余应力是影响零件加工变形的重要因素,有效的应力释放可以提高零件的加工质量。对此利用UGNX软件进行了数控编程,并利用VERICUT软件进行仿真,以最大切削厚度为目标进行了切削参数优化,优化后的程序能够有效的提高加工效率,并且探讨了以保证加工质量目标的刀轨编程策略和方法,有效的解决了飞机结构梁铣削加工过程中产生变形的问题。     

铜合金薄壁零件工艺探究

分析了利用铜合金挤压材加工成的环状薄壁零件变形、尺寸超差、磕碰的产生原因。并通过生产实验,确定了合理的加工工艺路线,降低了生产成本,提高了产品质量。     

化学铣切保护涂料体系材料对化铣槽液性能影响研究

化学铣切保护涂料体系材料主要由化学铣切保护涂料、化铣保护涂料快干修补胶、化铣保护涂料线密封剂构成,本文研究了化学铣切保护涂料体系材料多批次工程化产品在经过化铣工序后产品的漆膜表面状况是否发生变化、加工零件的铣切边的平直性以及浸蚀比的大小是否满足要求,判断化学铣切保护涂料体系材料经过三批次工程化产品的化铣工序验证之后是否会对化铣槽液产生影响。结果表明：化学铣切保护涂料体系材料经过批次化铣加工之后,化铣效果保持良好,不会对化铣槽液产生影响。     

一种连接平面碳纤维牺牲层铣切加工方法

正本发明公开一种连接平面碳纤维牺牲层铣切加工方法,用于飞机复合材料后机身与垂尾连接的对接平面碳纤维牺牲层的铣切加工,包括如下步骤:(1)将后机身前段装配件进行定位,后机身前段产品装配完成后不下架,与装配工装一起在平面铣切设备的加工区域内进行定位;(2)选择平     

化铣工艺的特点

正与一般机械加工方法相比,化铣工艺主要有以下特点:1)对某些焊接、铆接、胶接等方法组成的组合件,可作为一个整体结构直接进行化铣加工,缩短了生产周期。2)一般机械加工方法难以加工或无法加工的薄壁、易变形、大面积的零件,只要化铣槽尺寸允许,无论零件材料的状态如何,都可采用化铣方法     

高精度塑料零件的选材和机械加工

主要介绍高精度塑料零件的选材要求,研究塑料切削加工的特点,针对影响塑料切削加工质量的因素提出了具体的对策及经实践验证可改善和提高塑料切削加工质量的方法,探讨了铣切加工高精度塑料零件时的铣切工艺、铣切刀具和加工参数的选择原则。     

数控铣精密薄壁零件加工工艺探讨

在我国薄壁精密零件机不断革新发展,实际应用具有很久远的历史。其主要特征表现在对精密度具有很高的要求、零件的自身结构也极为复杂等。在实际操作中,根据精密薄壁零件不同的结构特点以及不同工序的制造工艺,提出改进数控铣薄壁零件的加工过程,通过采用UG软件建模,自动编程生成薄壁的加工程序,摒弃以往磨的方式,采用数控铣进行加工薄壁,铣薄壁时要谨记用砂布卷来替代数控铣刀。加工过程要根据零件结构特点,科学合理选择刃具及工具。对于复杂的工艺路线要科学的进行整合调整,使得加工工艺更简捷化。经过大量实践应用以及相关实验测量结果数据分析,此种加工方案是实用可行的。与此同时,还需要不断开发新的数控设备,为以后新机研制过程中,数控铣精密薄壁零件加工提供更多的帮助,奠定基础。     

基于数值模拟分析的合金焊接工艺优化试验

针对高温合金薄壁机匣焊接加工效率低、成本高的问题，以2条环形焊缝的GH3536材料为研究对象，提出一种基于数值模拟分析的合金焊接工艺优化方案。通过数值模拟可知，电子束焊接变形量为2.5 mm,自动氩弧焊接的变形量为1.7 mm,故采用自动氩弧焊接作为高温合金薄壁机匣焊接加工工艺方案，并将其应用于实际高温合金薄壁机匣焊接加工中。结果表明，优化后的自动氩弧焊接加工工艺的检测时间、总加工时间和空程时间更短，分别缩短了28、230、255 min。焊接一次合格率由69%提高到93%,可实现高效、低成本的高温合金薄壁机匣焊接加工。     

Label behavior property attached on microcellular foamed parts

In comparison with the conventional foaming process, microcellular foaming by injection molding has the advantage of forming small bubbles of consistent size. Because of the reduction in the cycle time, the removal of sink marks, scale reliability, and weight lightening, microcellular foaming by injection molding is widely applied to electrical products, such as automotive parts, office automation equipment, and laptops. When microcellular foaming by injection molding is used with a resin such as polycarbonate, acrylonitrile butadiene styrene, or PC/ABS, microbubbles form. This enables the manufacture of cell phones, notebooks, and personal digital assistants (PDAs), which are impossible to produce with the conventional foaming technique because these products require a thin wall. For most thin‐wall products, spray and labeling processes are added. Therefore, research into the spray and labeling characteristics of injected foamed parts should come before applications. In this article, we analyze the swelling phenomenon that results from labeling on microcellular foamed parts. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 98: 289–293, 2005     

低速球磨对多壁碳纳米管球磨特性的影响研究

利用低速球磨机对催化化学气相沉积法制备的多壁碳纳米管进行了球磨。透射电子显微镜实验结果表明。低速球磨机球磨可以使多壁碳纳米管开口和变短，球磨5h后碳纳米管开口和变短效果已经很明显；球磨20h后，发现碳纳米管变短到出现明显的团聚现象。X射线衍射实验结果表明，球磨20h后仍为多壁碳纳米管，每一层碳管仍为规则的石墨化结构。     

X射线衍射研究球磨Si3N4粉末的特征

Ｓｉ３Ｎ４粉末在行星球磨机中以酒精为研磨液进行湿磨，直至１９５小时。采用Ｘ射线粉末衍射研究了Ｓｉ３Ｎ４粉末晶块尺寸值和晶烃量与研磨时间的关系，晶块尺寸值与晶格畸变量的分离基于两项宽化效应对布拉格角的依赖不同。结果表明：在最初５０小时的左磨中，晶块细化很快，超过１７０小时后，晶块不再减小；经１９５小时球磨，粉末晶块尺寸值从未磨样的０．２３μｍ减少到０．０７４μｍ；经计算得未磨样最小位错密度为ρＤ＝５     

Sulfur/graphitic hollow carbon sphere nano-composite as a cathode material for high-power lithium-sulfur battery

The intrinsic low conductivity of sulfur which leads to a low performance at a high current rate is one of the most limiting factors for the commercialization of lithium-sulfur battery. Here, we present an easy and convenient method to synthesize a mono-dispersed hollow carbon sphere with a thin graphitic wall which can be utilized as a support with a good electrical conductivity for the preparation of sulfur/carbon nano-composite cathode. The hollow carbon sphere was prepared from the pyrolysis of the homogenous mixture of the mono-dispersed spherical silica and Fe-phthalocyanine powder in elevated temperature. The composite cathode was manufactured by infiltrating sulfur melt into the inner side of the graphitic wall. The electrochemical cycling shows a capacity of 425 mAh g⁻¹ at 3 C current rate which is more than five times larger than that for the sulfur/carbon black nano-composite prepared by simple ball milling.     

尼龙11工程塑料的应用

介绍了尼龙11工程塑料的物理性能、化学性能及其在汽车、管道、电子电气等领域中的应用，并对其应用前景进行了展望。尼龙11以其高强度、耐冲击、耐磨损、耐油性好的独特性能，成为汽车工业的重要材料，已在汽车发动机、传动部件及受力结构件上得以应用。     

Comparison of residual stress predictions and measurements using excimer laser layer removal

Residual stresses in injection molded polymer parts can have a major effect on product performance and are therefore often undesirable. Two different models for residual stress formation in injection molded products exist in the literature. The first model assumes that stresses in molded parts are identical with free quench stresses. Deviations are attributed to molecular orientation effects. The second model assumes that no slip occurs and that stresses are related to the holding pressure. Careful measurements should be able to differentiate between these models. In this study the layer removal stress measurement technique was improved by using an excimer laser for the milling operation. In that way stress relaxation during measurements was avoided and thin layers of uniform thickness could be removed. Both resolution and measurement accuracy were greatly improved. Stress distributions in polycarbonate plates molded under low holding pressures turned out to be of the free quenching type, whereas those molded under higher pressures were of the pressure type. All stress distributions could be predicted by a recent theory that comprises the two models as limiting cases.     

Characterisation of mechanical properties of thin polymer films using a bi-axial tension based on blow-up test

Abstract

Blow-up tests were carried out to evaluate mechanical properties of the thin Nylon film used as bagging films. A new method for calculating bi-axial stress and strain of the thin film in blow-up tests was developed based on the theory of membrane with large strain solutions. The bi-axial tensile elastic modulus, Poisson's ratio, yield strength, fracture stress and bi-axial stress–strain relationship of the thin Nylon film were obtained. Meanwhile, uni-axial tensile tests were conducted and the results were compared with those from blow-up tests. For the Richmond HS-8171 thin Nylon film studied, the bi-axial tensile elastic modulus was slightly more than 2 times greater than the uni-axial tensile elastic modulus. The yield strength was the same for both bi-axial and uni-axial tension. The bi-axial fracture stress was about one-third greater than the uni-axial one, while the bi-axial failure strain was about two-thirds greater than the uni-axial counterpart.     

聚四氟乙烯缠绕制件的生产和应用技术

着重介绍用缠绕法生产聚四氟乙烯防腐设备衬里异形零部件的技术,并可加工各种薄壁而复杂的内衬件     

Shear amplification of orientation in Nylon 11/clay nanocomposites during melt casting and resulting electrical properties

In this study, the effect of organically modified clay on the orientation enhancement in Nylon 11 in melt casting was investigated. Nylon 11 was mixed with 1 and 3 wt% Cloisite 20A using twin screw extrusion and they were cast into films with varying take-up speeds. The addition of clay in Nylon 11 helped increase orientation levels substantially in melt cast films, both as a function of clay concentration as well as take-up speeds. This was primarily due to shear amplification effect caused by the movement of adjacent clay nanoparticles due to the shear flow gradient within the die. At low clay concentrations, the sub-T_m stretchability, and electrical breakdown strength improve as the presence of clay reduces inter/intrachain hydrogen bonding. At higher clay concentrations, both orientation and electrical breakdown levels decrease. The latter is primarily caused by increased percolation path of charge carriers. Nevertheless, clay nanoplatelets were very effective in their role as melt processing aids, as they enhance orientation levels of Nylon 11 thin films by shear amplification effect where they increase local chain orientation of chains trapped between clay platelets while their orientation relaxation is suppressed.     

机械涂覆技术在光催化材料制备中的应用进展

机械球磨技术因工艺简单、成本低廉而受到广泛关注,特别在粉体材料的混合、细化及合金化等领域有着广阔的应用前景。综述了由机械球磨原理发展而成机械涂覆技术的应用现状,包括用于材料表面改性的功能涂层和光催化降解的薄膜材料制备。分析了工艺参数、涂覆材料及涂覆基底等因素对涂覆效果（厚度）的影响规律,并对该技术在薄膜制备中表现出的简便、廉价且可在球形等形状复杂基底上成膜的独特优势做了讨论。基于当前机械涂覆技术制备的薄膜形貌、厚度不可控且成膜基底材质受限等现状,指出今后应该向拓展成膜基底材料类型和加快推进光催化薄膜材料的实际应用方向发展。