自动化电刷镀机床的开发

为解决刷镀自动化问题,开发了自动化刷镀机床,该设备为工件提供旋转运动,同时为镀笔提供径向和轴向运动,从而可以调节镀笔和工件之间的相对运动速度和轨迹;该设备实现了镀液的自动供给和调整,同时可以调节镀笔和工件之间的压力,从而有利于获得均匀和性能良好的镀层;此外,该设备实现了镀层厚度的自动检测.     

对护板零件电镀镉层厚度均匀性控制的研究

航空用常规镀镉对具有复杂形状的加强护板类零件,其边角区域镉层厚度过厚且易出现树枝状,甚至脱落.本文通过采用两种不同操作方式,对具有复杂形状的加强护板类零件表面镀镉层厚度分布进行对比分析,研究镀层厚度均匀性的影响因素,并得出生产过程中尽可能避免尖端效应的方法,从而控制镀层厚度均匀性,提升加强护板类零件表面镀层质量.     

镀前螺纹紧固件用螺纹量规的设计

分析了镀前、镀后螺纹工件尺寸的变化,不同镀层厚度对镀前尺寸的影响也不同,相应地检测镀前工件用螺纹量规也需分别设计.     

Ni-Fe-W合金镀层的结构形貌及摩擦学性能研究

利用脉冲电沉积的方法制备了Ni-Fe-W合金镀层,讨论了镀液中W的含量对Ni-Fe-W合金镀层组织结构的影响,以及镀液成分对镀层硬度及厚度的影响。分析了Ni-Fe-W合金镀层在干摩擦条件下摩擦因数随载荷以及速度的变化情况,并与Ni-W合金镀层以及硬铬镀层进行了比较,探讨了干摩擦条件下Ni-Fe-W合金镀层的摩擦磨损机制。在高速轻载时,Ni-Fe-W合金镀层在摩擦过程中会生成有弥散强化作用的中间硬质相和起固体润滑作用的氧化物,使其磨损表现为轻微的磨粒磨损。     

向您介绍高校技术转让项目

化学镀镍合金技术化学镀镍合金是利用还原剂在镀液中将镍离子催化还原,在镀件表面沉积镍合金镀层的表面镀覆技术。其工艺特点:①镀覆过程不需外电源驱动。②镀液无毒,废液易于处理。③均镀能力强,形状复杂的零件可获得均匀的镀层,镀层厚度差控制在1～3μm 内,设定的镀层厚度可控制在±5～10μm 内。④孔隙率小。⑤镀速可调整。⑥镀液再生性好。⑦适用基材     

镀层厚度控制器

镀层厚度控制器是电刷镀设备必备的装置。主要利用集成电子器件，在实验的基础上研制了一种新型镀层厚度控制器，并分析了控制器的性能、工作原理及其设计特点。试验结果表明：所研制的镀层厚度控制器不仅具有体积小、精度高、性能可靠的特点，而且还可以与各种刷镀电源配合使用，实现对刷镀层厚度的设定与控制。     

向您介绍高校技术转让项目

▲化学镀镍合金技术 化学镀镍合金是利用还原剂在镀液中将镍离子催化还原,在镀件表面沉积镍合金镀层的表面镀覆技术。其工艺特点:①镀覆过程不需外电源驱动。②镀液无毒,废液易于处理。③均镀能力强,形状复杂的零件可获得均匀的镀层,镀层厚度差控制在1～3μm内,设定的镀层厚度可控制在±5～10μm内。④孔隙率小。⑤镀速可调整。⑥镀液再生性好。⑦适用基材广,铁基合金、有色金属、陶瓷、玻璃、塑料及有机物等均可施镀。其性能特点:①硬度高,镀态硬度为500～600HV0.1(49～     

耳片铆接孔镀前铰刀和塞规的设计

为了防止黑色金属零件的锈蚀，经常采用电镀一层金属或发蓝来进行表面处理。常用的电镀方法有镀锌、镀镉和镀铬。表面处理后，可以提高零件的使用寿命并使外形美观。 图1是我厂生产的耳片的产品图样，它的2×φ6H11（07500.+）mm是要求镀后达到的尺寸。该零件的表面处理为镀锌，镀层厚度为5~12μm。要达到镀后φ6H11 mm的要求，就必须预留出镀层厚度，这样在镀后才可达到图样的尺寸要求。按照图样的最大极限尺寸镀最薄的镀层厚度、最小极限尺寸镀最厚的镀层厚度的原则，这个零件两孔的镀前尺寸应为： 最大极限尺寸=6.075+0.005×2=6.085 mm…     

涂镀技术在修理中的应用

涂镀是在表面局部快速电沉积金属的新技术。涂镀层具有良好的机械性能,涂镀层与基体金属的连接强度比较好,工艺灵活,适用于碳钢、铸铁、合金钢、镍和一些铬、铝、钢及其合金。涂镀过程中工件的加热温度<70℃,不会引起变形和金相组织变化,涂镀层尺寸精确,采用安培——小时计监控涂镀层厚度,精度可达±0.01毫米,在要求不高的场合,不需要机械加工。涂镀能显著提高零部件的使用寿命和可靠性,提高设备的利用率,减少配件的     

无氰镀锌新工艺及试验分析

介绍了一种以氢氧化钠、氧化锌为主盐的无氰镀锌工艺.测定该工艺镀液的电流效率、镀层沉积速率、镀液的分散能力、镀液的深镀能力以及镀液的稳定性的结果表明,该无氰镀锌镀液的电流效率与镀层沉积速率都较高,镀液的分散能力和镀液的深镀能力较好,且该镀液的稳定性较好.对锌镀层的结合力、耐蚀性能作了测定,结果表明该锌镀层结合力较好,具有良好的耐腐蚀性能.     

A magnetic method for testing the thickness of two-sided weakly magnetic coatings by a nonmagnetic base

The general case where the depth of the informative zone is greater than the thickness of a nonmagnetic base having a two-sided weakly magnetic coating is considered. In this case, the informative signal is determined by the thickness of the base and coating on both sides. A technique for separately measuring the coating thickness on either side taking into account the effect of both coatings on the informative signal is proposed as applied to the magnetodynamic method.     

基于HMI与PLC的位移闭环控制系统在大型钢管防腐涂层自动涂装生产线上的应用

针对大型钢管防腐涂层在自动涂装生产线中由于大型钢管的行进速度变化不均造成漆膜厚度不均匀、油漆损耗过大的问题,在大型钢管防腐涂层自动涂装生产线中采用了人机界面(HMI)与可编程控制器(PLC)控制系统、激光位移传感器测速装置对大型钢管行进速度实行闭环控制,控制大型钢管匀速行进。通过实际应用分析,对比测量开环、闭环速度历史曲线变化情况,同时在喷涂参数相同的情况下,研究了闭环控制前和闭环控制后大型钢管防腐涂层漆膜厚度的变化情况。研究结果表明:基于HMI与PLC的位移闭环控制系统能有效地解决由于大型钢管在行进过程中速度变化不均所造成的漆膜厚度不均匀、油漆损耗过大的问题,漆膜厚度的变化幅度由原±30%降至±10%左右,证明基于HMI与PLC的位移闭环控制系统在大型钢管防腐涂层自动涂装生产线上的应用是可行的。     

ANALYSIS ON THERMAL ELASTO-PLASTIC ASPERITY CONTACTS OF LAYERED MEDIA

A thermal elasto-plastic asperity contact model is investigated, which takes into account the steady-state heat transfer and the asperity distortion due to thermal elasto-plastic deformations. A hard coating and a soft coating are applied to study the correlations between contact area and contact pressure, average gap and contact pressure, coating thickness and contours of the contact stress distribution, etc. The effects of material properties, coating thickness, frictional coefficient, and the heat input combinations on the stress distribution are investigated and discussed. The frictional heat input increases the maximum value of yon Mises stress. Finally, the appropriate thickness of the hard coating is also discussed. To protect the substrate, one can choose hard coating and the thickness of that is suggested that can be hc=70 Rm.     

高反膜的镀制实践与探索

光学薄膜的厚度对光学元件的性能有决定性的影响,因此精确控制膜厚就成为了关键。分析了石英晶体监控法,介绍了IC/5镀膜自动控制仪。利用IC/5镀膜自动控制仪在现有镀膜机组上镀制出了高性能的高反膜。实验表明所镀膜层的光机性能优异,在光通信和激光器领域具有广阔的应用前景。     

真空紫外Al/MgF_2反射镜

采用三步热舟蒸发制作法研制了真空紫外Al/MgF2反射镜,研究了改善制备工艺有效提升反射率的方法。在两层Al/MgF2反射镜制备过程中,第一步在室温石英基板上快速蒸发厚约70nm的铝膜;第二步在铝膜表面迅速蒸发厚约10nm的MgF2;第三步先对基板加热到一定温度后,再在Al+MgF2的表面上蒸发15~20nm厚的MgF2。通过调整基板温度(室温、100℃、200℃和300℃),研究了基板温度对Al/MgF2反射率的影响。真空紫外反射率计测试结果表明:第二步蒸镀MgF2之后增加基板温度有利于提高反射镜的反射率;MgF2薄膜的厚度对反射镜的反射率起到一定的调制作用,MgF2厚为26.7nm的反射镜在122nm处的反射率达85%。在实验室环境下存放1个月和5个月后,反射镜的反射率没有变化。研究结果为真空紫外光学系统需求的高性能光学元件的研制提供了技术基础。     

An investigation on the micro cutting performance of diamond-like carbon coatings using finite element method

In an effort to prolong the tool life and improve the tooling performance in micro cutting, it is attractive and promising to apply diamond-like carbon (DLC) coatings on micro tools. Comprehensive understandings of micro cutting performance under various coating circumstances are essential for choosing optimum coating conditions so as for potentially improving cutting tool designs. In the study, the cutting characteristics of a DLC-coated tool has been extensively evaluated and compared with those of an uncoated tool under constant and various uncut chip thickness (UCT) using 2D plane-strain finite element method (FEM). The thermo-mechanical modelling approach has been validated at different UCT in micro milling. Besides, the influence of coating friction coefficient, coating thickness as well as UCT on the cutting forces and tool temperatures has been determined and analysed through design of experiment. It is found that appropriate UCT in micro cutting is of the greatest importance for achieving desirable coating performance of micro tools.     

Development of amorphous carbon coating with luminescent silica/CdSe/ZnS quantum dots underlayer for wear monitoring

Amorphous carbon (a-C) coating with luminescent wear-sensing underlayer is developed for achieving the tribological coating with wear monitoring capability. Wear monitoring of a-C coating by luminescent spectroscopy to determine the remaining thickness of the coating after the wear test is also demonstrated. The coating structure consists of a-C films deposited by R.F. magnetron sputtering method onto the luminescent layer, which is made from silica coating containing CdSe/ZnS quantum dots (Silica/QD). A thin Si-intermediate layer is added between a-C and silica/QD layer for adhesion improvement. The physical as well as tribological properties of the coatings are analysed. Furthermore, wear monitoring of a-C films is also demonstrated to determine the remaining coating thickness after the tribological test. The demonstration is carried out by firstly formulating a relation between luminescent intensity detected from the coating and coating thickness. Then the luminescent intensity is measured again from the wear track. The remaining thickness is finally determined by using the relationship between luminescent intensity and coating thickness. The fabricated coating exhibits a smooth surface with the average surface roughness of 1.35 nm and a friction coefficient of 0.1. The demonstration of wear monitoring shows that the remaining thickness of the coating after the tribological test determined by luminescent spectroscopy is compared well with the thickness measured by profilometry. This suggests that wear monitoring of a-C films by luminescent spectroscopy technique is feasible.     

涂层材料特性对滚子轴承润滑性能的影响*

涂层材料被广泛应用于滚子轴承中以改善界面性能和提高疲劳寿命,为了探讨涂层材料性能对滚子轴承润滑性能的影响,基于流体力学与接触力学理论,建立带涂层的有限长线接触弹流润滑模型,探讨不同载荷、速度以及涂层材料特性对油膜压力、油膜厚度的影响。研究表明：随着涂层厚度的增加,硬涂层使得最小油膜厚度先增加后减小,而软涂层轻载时使得最小油膜厚度先减小后增加,重载时最小油膜厚度一直减小;随着速度的增加,出口区二次压力峰值增加,硬涂层尤为明显,并且油膜厚度也增加,油膜平坦区域减小,出口区油膜紧缩值增加。为提高润滑性能,当使用较厚软涂层时应考虑增加滚子凸度量,而使用较厚硬涂层时应考虑减小滚子凸度量。     

基于钝尾缘翼型叶片的三维风力机性能分析

随着风力机向大型化发展,为有效提升风力机叶片的性能以及结构强度,将钝尾缘翼型应用于风力机叶片设计。以NACA639XX系列翼型为基准翼型,通过Hicks-Henne型函数和钝尾缘函数对翼型进行参数化拟合,使用多岛遗传算法优化得到层流钝尾缘翼型族(USST-XXX)。将此翼型族中相对厚度为21%的USST-211翼型与NACA63921层流翼型替换NREL PhaseVI叶片截面的S809翼型,建模得到两种三维风力机叶片,采用数值模拟的方法,对这两种叶片不同风速下的流场进行分析,并与NREL Phase VI风力机叶片的气动性能进行对比。数值模拟结果表明,在额定风速附近,采用层流钝尾缘翼型所构造的新叶片风力机的风能利用系数高于其他两种叶片。研究结果表明优化得到的层流钝尾缘翼型族可以有效提升风力机气动性能,在大型水平轴风力机叶片设计方面具有良好的应用前景。     

Mass thickness determination by electron energy loss for quantitative X-ray microanalysis in biology

As is well known, electron energy loss spectroscopy can be used to determine the relative sample thickness in the electron microscope. This paper considers how such measurements can be applied to biological samples in order to obtain the mass thickness for quantitative X-ray microanalysis. The important quantity in estimating the mass thickness from an unknown sample is the total inelastic cross section per unit mass. Models for the cross section suggest that this quantity is constant to within ±20% for most biological compounds. This is comparable with the approximation made in the continuum method for measuring mass thickness. The linearity of the energy loss technique is established by some measurements on evaporated films and quantitation is demonstrated by measurements on thin calcium standards. A significant advantage of the method is that the energy loss spectrum can be recorded at very low dose, so that mass thickness determination can be made before even the most sensitive samples suffer damage resulting in mass loss. The energy loss measurements avoid the necessity to correct the continuum measurement for stray radiation produced in the vicinity of the sample holder. Unlike the continuum method the energy loss technique requires uniform mass thickness across the probe area, but this is not usually a problem when small probes (<100 nm diameter) are used.