电子束焊接过程束流品质的调控技术

研究到达工件前的束流品质,束流品质的量化表征是通过基于二次电子的间接测量方式和基于能量密度测试传感器的直接测量方式相结合来实现。通过自动束流对心和矫形程序实现对束流品质偏移距离和形貌因子两个表征参数的调控,并使其达到最优。研究电压、束流、聚焦电流等电子束焊接工艺参数与束流的三维能量分布指标的内在联系。通过建立的二次方模型,利用Design-Expert软件优化(Optimization)模块不仅可以预测不同电参数作用下的四个表征参数的具体数值,而且能根据设定的四个表征参数推算出三个电控参数的优化方案,选择期望度最大的一组电控参数值作为调控的基本参数。在此基础上利用电子束能量直接测试系统,进行电控参数的微调,并实时监测四个三维特征参量的变化,直至达到调控的预定值。     

Investigation of the formation of the secondary current signal in plasma in electron beam welding with oscillations of the electron beam

The results of investigation of the formation of the secondary current signal in plasma and electron beam welding with the oscillation of the beam along and across the joint are presented. The secondary signal is analysed by the synchronous storage method. The results show that the parameters of the function, which is the result of processing the secondary signal by the synchronous storage method, depend on the focusing conditions.     

Determination of the parameters of the beam geometry in an electron beam welding installation

Abstract

With the aid of statistical methods, mathematical relationships between given technological parameters and installation dimensions are found. Using the algorithms obtained, the plant settings are calculated from the target quantities using a control computer (K1520) as required and for any value within the range of settings, and these are set in the EB installation.     

Automatic electron beam alignment adjustment system and automatic filament current adjustment system for electron beam welder

Recently, the electron beam welders with high acceleration voltage (more than 100 kV) and high electrical power (more than 15 kW) have been reviewed the role of the high-energy electron beam density again, due to space or aircraft development or automobile industry desired high productivity and high accurate welding for saving energy. NEC group have supplied these electron beam welders. This time, the automatic alignment adjustment system of the electron beam orbit and the automatic adjustment system of filament current were developed and put to a practical use. As a result, the great effectiveness for the stability of welding quality was apparent.     

电子束扫描控制系统

设计了一个可编程电子束扫描控制系统，能够使电子束受控的偏摆产生任何图形。该系统的控制软件能够计算、控制电子束偏摆获得所要的波形，这些波形是由若干独立的数据点构成。使用该系统，温度梯度可以很精确地调整，且误差比较小。该系统可以很容易地应用于原有的电子束加工设备上，适用于电子束硬化、重熔、钎焊和表面改性处理。     

电子束焊接技术研究及进展

简要介绍了电子束焊接技术的发展、基本原理以及应用范围。着重介绍了电子束钎焊、活性剂电子束焊接、电子束复合焊接、电子束填丝焊、局部真空电子束焊接、电子束扫描焊接等电子束焊接新技术在国内的研究现状,并对电子束焊接未来的发展做出了展望。     

国内外电子束熔丝沉积增材制造技术发展现状

随着增材制造技术的不断发展,各种增材制造技术,如电弧增材制造、激光增材制造和电子束增材制造等,在其相应的领域内展开了广泛的研究.文中总结了电子束熔丝沉积增材制造技术的特点.重点介绍了国内外对电子束熔丝沉积技术开展的研究工作,简要介绍了国内外学者在电子束熔丝沉积技术设备和工艺方面取得的最新研究成果.分析了电子束熔丝沉积技术目前亟需展开的研究工作,并展望了该技术应向活泼难熔金属、复合材料、梯度材料制备与大型复杂构件的增材制造等方向发展.     

电子束熔丝沉积快速制造技术研究现状

电子束熔丝沉积快速制造技术具有制造效率高、真空环境有利于零件保护、内部质量好和可实现多功能加工等优势,非常适合大型金属材料结构的快速制造,近年来成为高能束快速制造技术的研究热点。在对比分析典型高能束快速制造技术的基础上,总结了电子束熔丝沉积快速制造技术的特点,综述了国内外电子束熔丝沉积快速制造技术的研究进展,并展望了电子束熔丝沉积快速制造技术的发展前景。     

Modelling and simulation of electron beam melting

In recent years, the scientific and industrial relevance of additive layer manufacturing (ALM) has grown. In the metal area of ALM, the capacity of laser technologies is noticeably limited. This is mainly due to an inertial beam deflection device, which is also referred to as a mirror galvanometer. In contrast, the electron beam technology offers high power density as well as considerable scanning rates. Therefore, electron beam melting (EBM) seems to be suitable for processing a broad variety of alloys in an economic way. In particular, the enormous scanning rates which can be realized by use of an electron beam enable an economic manufacture of high quality parts. However, profound expertise is required in order to establish EBM as an industrial production technology. By means of mathematical–physical modelling, process stability of the melting step is being increased. Moreover, by solving a detailed thermal model using the finite element method (FEM), substantial knowledge of adequate parameter settings in dependence of the utilised material is developed. Finally, a process window as a function of scan speed and beam power is developed based on experimental results.     

Effect of modulation of electron beam current on the nature of auto‐oscillations and formation of the welded joint in electron beam welding

Special features of the application of power sources for mechanized welding are described. The advantages of the MAGMA-315 inverter power source in comparison with traditional rectifiers are investigated.     

Nano-pillars using electron beam lithography and electroplating

Mechanical testing of submicrometer-sized metal pillars has shown significant strengthening on decreasing the pillar dimensions. Analysis of such experiments is complicated, however, because the traditional focused ion beammethod for making the     

真空电子束钎焊工艺研究

探讨了真空电子束钎焊中,电子束束流、聚焦电流、加热时间等电子束钎焊工艺参数对钎料润湿性的影响及其规律,以及不同的电子束钎焊工艺参数对试件最高温度、加热速度、高温停留时间等温度场有关参数的影响作用。通过金相分析、扫描电镜和X射线能谱分析等手段,研究了BNi-2钎料钎焊不锈钢时的接头组织。     

The electron beam evaporation and deposition process

The electron beam evaporation and deposition (EBED) process produces virtually defect-free ingots, disks and cylindrical shapes. When produced by EBED, high-temperature alloys have virtually no inclusions and titanium alloys have essentially no low-density inclusions (Type I defects). Most alloys produced by the process have grain sizes of less than 10 μm and are superplastic. Envisioned applications of EBED include the production of: complex, cylindrical shapes; high-purity sputtering targets; higher-fabricability alloys; and hot-section disks and compressor for aircraft engines.     

Out of vacuum electron beam welding certain materials

Progress is not only being recorded in relation to finished products. Steelmakers themselves have also worked hard by integrating welding into their strategy.     

电子束快速成形温度场模拟

利用ANSYS软件模拟电子束快速成形过程的温度场分布情况,电子束能量输入用高斯面热源表示,由于快速成形过程在真空室中进行,因此只考虑热辐射散热。同时模拟了单圆扫描、多个圆同时扫描和多个圆依次扫描的温度场分布.结果表明,对于成形一定宽度的圆筒,多个圆从外到里依次扫描的方式比较理想,用较小的束流就可以达到熔点以上温度,扫描范围与成形范围趋于一致,得到的成形件表面均匀平整,成形精度较多个圆同时扫描时容易控制.利用"生死单元"技术模拟了层层堆积快速成形的过程,从中可以了解快速成形过程的温度场变化情况,以优化工艺参数.