钽及表面离子渗氮层的耐碱腐蚀性

应用弱极化区三点法和线性极化法对钽及表面离子渗氮层在10％－NaOH中的腐蚀电流和极化电阻进行了测量，给出了腐蚀电流与离子渗氮工艺之间的回归方程。     

滚珠丝杠副刚性试验台加载及测量系统工装设计

介绍了滚珠丝杠轴向静刚度试验台测试原理和方案,针对力加载系统工装和位移测量系统工装的设计做了详细讨论。讨论了位移传感器个数以及布置方式对测量位移值的影响,设计出定位精度高使用方便的位移传感器工装,提出偏离度概念来评价位移测量系统和加载系统的合理性。提出了点到面、点到点、点到线再到面的三种力加载方案,通过对丝杠变形的测量结果表明点到线再到面的设计有很好的调心功能和较低偏离度。     

基于CAD点云模型的CMM离线编程技术研究

三坐标测量机(CMM)的离线编程较复杂,尤其针对未知三维CAD模型的工件更加难于实现离线编程。为此提出基于CAD点云模型,针对工件中常见的平面和圆柱面等特征,通过编程方式完成特征异常点删除和提取特征点操作,编制DMIS自动测量程序,模拟仿真检验后进行CMM在线测量。实例验证:该方式较易编制CMM离线程序,实现了CMM的自动稳定测量。     

单片机多机通讯技术在锻压设备测量中的应用

介绍了MCS－51单片机多机通讯技术在曲柄压力机多点测量中的应用，并对其硬件结构和软件设计方法进行了阐述。     

板材杨氏模量对称三点弯曲测试方法及测试装置

金属板材在弹性对称三点弯曲时最大挠度与集中力呈线性比例关系,由该关系可求出板材的杨氏模量。文章提出利用对称三点弯曲的原理测量金属板材杨氏模量的方法,并设计加工了相应的试验装置,该装置结构简单,制作成本低,挠度测量采用百分表,测量精度高。实测了1mm厚铝板和铜板及3.1mm厚钢板的杨氏模量,测量结果稳定可靠。     

TiNi形状记忆合金的耐蚀性

ＴｉＮｉ形状记忆合金的耐蚀性捷克的科学家研究了ＴＩＮｉ形状记忆合金在盐水溶液中的耐蚀性。所研究的合金成分是Ｔｉ－－４５ａｔ％Ｎｉ和Ｔｉ－－５５ａｔ％Ｎｉ。在０．９％ＮａＣＩ水溶液中，用动电位法测量了合金的耐点蚀性，并与３１６Ｌ型奥氏体不锈钢（作为人体...     

强冲击载荷下 Ta-W 合金的塑变特征

用轻气炮加载和冲击波测量技术测量了Ｔａ和Ｔａ－Ｗ合金在１０４／ｓ～１０６／ｓ应变率下的形变行为。根据平板冲击载荷条件，实验上建立了Ｔａ－Ｗ合金的动态响应的本构关系，测量出合金的各动力学特性参数。本研究还就Ｔａ和Ｔａ－Ｗ合金在高应变率下的塑性形变方式、Ｗ的添加和应变率对动态形变过程及动力学性能的影响进行了观察分析和讨论。     

单片机多机通讯技术在锻压设备测量中的应用

介绍了ＭＣＳ－５１单片机多机通讯技术在曲柄压力机多点测量中的应用，并对其硬件结构和软件设计方法进行了阐述。     

13MnNiMoNbR厚板焊接温度场数值模拟

采用多点铠装热电偶,实际测量13MnNiMoNbR厚板焊接件表面和内部的温度,得到了三个有效测温点的温度变化规律,获得了焊接过程中实际温度场的分布规律;利用有限元软件ABAQUS,模拟了厚板焊接温度场,得到了温度场的变化规律,并与测量结果进行对比分析.结果表明,测量与模拟的温度场的变化规律基本一致,有效点的最高温度测量...     

1996年世界钛工业的回顾与展望

用轻气炮加载和冲击波测量技术测量Ｔａ和Ｔａ－Ｗ合金在１０＾４／ｓ￣１０＾６／ｓ应变率下的形变行为。根据平板冲击载荷条件，实验上建立了Ｔａ－Ｗ合金的动态响应的本构关系，测量出合金的各动力学特性参数。本研究还就Ｔａ和Ｔａ－Ｗ合金在高应变率下的塑性形变方式、Ｗ的添加和应变率对动态形变过程及动力学性能的影响进行了观察分析和讨论。     

Determination of appropriate sampling conditions for three-dimensional microtopography measurement

Currently, there are no national or international standards available for the measurement of surface roughness in three-dimensions. The selection of measuring parameters (for example, the sampling interval and area) therefore relies largely on the experiences of users and is fraught with subjectivity. This is inconvenient, particularly for inexperienced users; moreover, this practice makes it difficult for inter-comparisons of measurement results to be conducted.

This paper aims to develop an objective criterion for selecting appropriate sampling conditions. A philosophy of surface roughness measurement in terms of the Nyquist wavelength limit is discussed. A sampling interval selection approach, based on spectral analysis, is then proposed. The proposed approach is not only applicable for the three-dimensional measurement scenario, but is also useful for the traditional two-dimensional measurement approach. The proposed technique has the added advantage that it can also be used to check the suitability of the measurement probe tip for any particular application. Experimental results based on measurements carried out on a large range of engineering surfaces (using a stylus instrument) are presented to demonstrate the effectiveness of the proposed approach.     

一种轴类零件径向圆跳动误差三点法测量研究

针对目前某企业轴类零件人工测量精度较低的问题,提出一种非接触激光三点法测量方法,建立了数学模型,设计了数据采集系统和数据实时系统,该方法能分离出圆度误差和回转误差,提高了测量精度。并且通过案例验证了方案的可行性,为轴类零件径向圆跳动误差研究提供了参考。     

T2紫铜-45钢电子束焊双材料界面性能与裂纹偏转

焊接接头性能与缺陷一直是焊接材料相关课题的重要方面,大量的研究描述了焊接材料的接头性能与特征,但异种焊接材料的界面与开裂问题研究并不充分. 文中对T2紫铜-C45钢电子束焊接双材料界面强度和裂纹开裂的问题,首先采用标准拉伸和三点弯曲试验,得到该材料焊缝区抗拉强度、屈服强度、弹性模量参数,并依此计算判断出断裂韧性值;其次对拉伸和三点弯曲试验试样的宏观和微观断口分析,表征其断口形貌特征,得出断口断裂类型为准解理和沿晶脆性复合断裂模式;基于试验分析结果对裂纹开裂偏转路径进行讨论,得出裂纹沿焊缝区扩展并偏向T2紫铜端;最后以实测参数为基准,基于ABAQUS有限元分析得出三点弯曲试验下焊缝区的裂纹扩展和偏转方向结果,为该种异种金属焊接材料接头性能的提升提供了依据.     

Reduction of lift-off effects for pulsed eddy current NDT

The lift-off effect is commonly known to be one of the main obstacles for effective eddy current NDT testing as it can easily mask defect signals. Pulsed eddy current techniques, which are believed to be potentially rich of information, are also sensitive to the effect. An approach using normalisation and two reference signals to reduce the lift-off problem with pulsed eddy current techniques is proposed. Experimental testing on the proposed technique and results are presented in this report. Results show that significant reduction in the effect has been achieved mainly in metal loss and sub-surface slot inspection. The technique can also be applied for measurement of metal thickness beneath non-conductive coatings, microstructure, strain/stress measurement, where the output is sensitive to the lift-off effect.     

异形小凸模的3点固定法

介绍了异形小凸模3点固定法的原理、结构和设计要点。并对比以往传统的固定方法。3点固定法通用性强，加工工序简单，凸模装配方便，更换容易。     

非线性电液位置伺服系统的自学习滑模模糊控制

针对电液伺服系统存在参数变化、负载干扰等非线性因素，且难以建立精确的数学模型用于实时控制的特点，将一种自学习滑模模糊控制方法应用于电液伺服系统，并将滑模控制策略应用于模糊控制中，建立以滑模函数值为输入、伺服阀控制电压为输出、模糊规则只有11个的简单模糊控制器，通过在线学习调整模糊规则使系统状态快速滑向状态平衡点。该控制方法结合了滑模控制和自适应模糊控制，鲁棒性强、结构简单。仿真和实时控制结果表明：在电液位置伺服系统中取得良好的控制精度和稳定性。     

Mo-Si-B三元系中T2相合金制备及其室温力学性能

通过放电等离子烧结(SPS)制备T2(Mo5SiB2)相合金,并采用SEM、XRD及压痕、压缩和三点弯曲等实验对合金的微观组织和室温力学性能进行表征。结果表明:SPS法以独特的等离子活化烧结方式制备出纯度高、致密且晶粒细小的T2相合金。该合金在室温压缩下几乎没有塑性变形,抗压强度为2907MPa;维氏硬度为17.86GPa,压痕法测得的断裂韧性为3.23MPa·m1/2,与三点弯曲法测得的3.34MPa·m1/2接近,沿{001}面发生解理断裂。共价键交替排列,是T2相室温脆性、高强度、高硬度的根本原因。     

往复式喷射沉积管坯制备中喷射高度的闭环控制

分析了往复式喷射沉积制备大壁厚管坯的工艺原理,研究了喷嘴喷射高度在线检测及闭环控制方法及技术。喷射高度控制系统包括漏包提升执行机构、沉积层厚度在线测量、基于PLC的喷嘴高度控制。提升执行机构采用伺服电机驱动的丝杠螺母机构,针对沉积层间断增长的特点,采用间断提升控制方式;研究了沉积层厚度在线测量方法,分析了收集基底形状误差对测量及控制精度的影响并提出多点测量方案。理论分析表明,采用三点测量法可消减基底形状误差的影响。对不同内径及壁厚的管坯进行了喷射实验,喷射高度累积误差低于5%,较好地满足了大壁厚管坯制备对稳定的喷射高度的要求。     

Neural network applications in surface topography

There is an industrial need for the measurement and classification of the topography of engineering surfaces - two-dimensional (2-D) analysis is fast, but limited in the usefulness of the results obtainable whilst the three-dimensional (3-D) approach offers greater scope. Unfortunately, the data analysis step for 3-D data characterisation can be time-consuming, and often requires a skilled metrologist. The approach has therefore been adopted only with reluctance for on-line work.This Paper presents an approach to on-line 3-D surface characterisation/classification (for quality control purposes) based on artificial neural networks (ANN). Inter-surface classification has allowed the authors to place any new surface received by the system into its correct manufacturing process group (honed, turned, shot-blasted etc.). The second part of this work - reported here - has enabled the authors to reliably and consistently place surfaces in different roughness categories (for example, worn and unworn). Such a system, together with the classification module previously developed, would serve as a quality control tool, by interrogating surfaces presented to it and making reliable predictions on the state of the manufacturing process.     

激光熔覆对改善等离子涂层界面结合性能的研究

研究激光熔覆对改善等离子涂层界面的作用,基体待喷表面采用激光熔覆工艺预处理,在涂层－基体的界面处形成成分、显微硬度呈梯度分布的熔覆层,三点弯曲试验结果表明：界面梯度有显改善喷涂材料的界面结合状况,使界面承受外载茶的能力提高,并用相关的有限元程序分析了试样承载时界面处剪切应力的分布。