Process Stability in Serial Production of Aluminium Foam Panels and 3D Parts

Powder Metallurgy (PM) technology is emerging as one of the most promising techniques for the manufacture of net shape components and panels of aluminium foam. Control of the stability of the aluminium foaming process is one of the key issues in a serial production. Since there are many different parameters to be controlled in the raw material, the precursor and the finished foam part, the best solution is to keep all these factors in one centre of competence to exclude external influences and transporting problems. The latest material for the foaming tools plays also a decisive role concerning a high surface quality and a constant heat generation within the foam. New developments such as a precursor testing equipment or a foaming optimized furnace construction guarantees constant production conditions to be equipped for a more and more demanding market.     

An electron beam lithography and digital image acquisition system for scanning electron microscopes

A low‐cost microcontroller based control and data acquisition unit for digital image recording of scanning electron microscope (SEM) images and scanning electron microscope based electron beam lithography (EBL) is described. The developed microcontroller low‐level embedded software incorporates major time critical functions for image acquisition and electron beam lithography and makes the unit an intelligent module which communicates via USB with the main computer. The system allows recording of images with up to 4096 × 4096 pixel size, different scan modes, controllable dwell time, synchronization with main power frequency, and other user controllable functions. The electron beam can be arbitrary positioned with 12‐bit precision in both dimensions and this is used to extend the scanning electron microscope capabilities for electron beam lithography. Hardware and software details of the system are given to allow its easy duplication. Performance of the system is discussed and exemplary results are presented.     

基于仪表总线的嵌入式接口设计

介绍了仪表总线M—BUS的发展与应用，论述了其通信中的接收、发送机制，在此基础上提出了仪表总线主机、从机嵌入式接口的软、硬件设计方案。在从机设计中采用接触式CPU智能卡实现计费管理，微处理器采用低电压、低功耗、高速度MSP430系列单片机。实际运行表明：所设计的主机接口传输距离远，带载能力强；从机接1：7功耗小、可靠性高、抗干扰能力强。     

钢渗铬层上金刚石薄膜的表面、界面结构及附着性

在钢渗铬层表面用化学气相沉积(CVD))法制备了金刚石薄膜.使用扫描电镜(SEM)、透射电镜(TEM)和压痕法研究了金刚石膜的表面、界面结构及附着力.用拉曼光谱分析了金刚石膜的纯度及非金刚石碳相.甲烷含量超过0.6%(体积分数)后,金刚石膜为球形纳米晶,形核密度＞107cm-2.用甲烷含量为0.6%(体积分数)沉积的金刚石膜表面的残余压应力为1.22 Gpa,而膜背面的残余压应力更高,达2.61 Gpa.压痕显示在19.6 N载荷下膜发生开裂.TEM观察发现,膜/基界面为微观非平面,有利于提高金刚石膜的附着力.     

大型煤粉锅炉炉膛传热分体式计算方法及其可视化编程

对大型煤粉锅炉炉膛分体式计算方法进行研究,把炉膛以大屏过热器低端为界分成上、下两个部分进行传热计算,并用ＶＢ为程序编制了友好的用户界面．     

COM服务器的伪异步技术及其实现

COM组件技术在Windows操作系统中发挥了极其重要的作用，但标准COM组件技术在实时操作性上不尽完善。作为补充可以用COM连接点技术和多线程技术来构造一种伪异步技术。本文详细描述了其实现原理．并根据技术细节提供了解决方案。     

Interfacial Oxides Evolution of High-Speed Steel Joints by Hot-Compression Bonding

The interfacial oxidation behavior of Cr4 Mo4 V high-speed steel(HSS) joints undergoing hot-compression bonding was investigated by using optical microscopy(OM),scanning electron microscopy(SEM),and transmission electron microscopy(TEM).In the heating and holding processes,dispersed rod-like and granular δ-Al₂ O₃ oxides were formed at the interface and in the matrix near the interface due to the selective oxidation and internal oxidation of Al,while irregular Si-Al-O compou...     

From defects creation to circuit reliability - A bottom-up approach (invited)

This paper presents a theoretical framework about interface states creation rate from Si-H bonds at the Si/SiO₂ interface. It includes three mains ways of bond breaking. In the first case, the bond can be broken thanks to the bond ground state rising with an electrical field. In the two others cases, incident carriers will play the main role either if there are very energetic or very numerous but less energetic. This concept allows us physically modeling the reliability of MOSFET transistors, and particularly NBTI permanent part, and Channel Hot Carrier (CHC) to Cold Carrier (CCC) damage. Finally, the translation of these physical models into reliability spice models is discussed. These models pave the way to Design-in Reliability (DiR) approach which seeks to provide a quantitative assessment of reliability - CMOS device reliability in this case - at design stage thereby enabling judicious margins to be taken beforehand.     

Knobology in use: an experimental evaluation of ergonomics recommendations

The scientific basis for ergonomics recommendations for controls has usually not been related to active goal-directed use. The present experiment tests how different knob sizes and torques affect operator performance. The task employed is to control a pointer by the use of a control knob, and is as such an experimentally defined goal-directed task relevant to machine systems in general. Duration of use, error associated with use (overshooting of the goal area) and movement reproduction were used as performance measures. Significant differences between knob sizes were found for movement reproduction. High torques led to less overshooting as opposed to low torques. The results from duration of use showed a tendency that the differences between knob sizes were reduced from the first iteration to the second iteration. The present results indicate that the ergonomically recommended ranges of knob sizes might differently affect operator performance.     

Coating of TiB2 dispersed Ti50Ni50 superelastic alloy layer onto Ti-6Al-4V alloy by spark and resistance sintering

The spark and resistance sintering (SRS) of a mixture of Ti, Ni, and TiB₂ powders was carried out to form a TiB₂ dispersed TiNi alloy layer onto a Ti-6Al-4V alloy substrate. The strength and delamination resistance of the surface layer were evaluated by three-point bending tests. The results showed that the bending strength of the specimen with the TiNi alloy surface layer without TiB₂ particles sintered at 1273 K was low because the crack initiation occurred at an early stage of loading in a thick interface layer containing brittle Ti-Ti₂Ni eutectic. By decreasing the sintering temperature to 1200 K, the bending strength increased and the crack initiation occurred from the surface because the interface layer was thin and did not contain the brittle Ti-Ti₂Ni eutectic. For the specimens with TiB₂ dispersed TiNi surface layer that was sintered at 1273 K, the bending strength was larger than that of the specimens with TiNi surface layer because the interface layer does not contain the Ti-Ti₂Ni eutectic and compressive residual stress generated in the surface layer during cooling process after SRS suppresses the crack initiation on the surface. The coating of TiB₂ dispersed TiNi alloy onto titanium alloys by SRS provides strong interface to prevent delamination of the surface layer, strong surface due to residual compressive stress, and wear-resistant surface due to the existence of hard TiB₂ particles and superelastic deformation of TiNi matrix.