ABSTRACT
Using Radial Basis Function Neural Networks ................................................ 237 11.6 Summary ............................................................................................................................. 239 References ..................................................................................................................................... 239
Electron beam welding (EBW) is a metal-joining technology that is about 60 years old [1]. Here, a high-energy focused electron beam (spot diameter of a few microns to a few
millimeters) is used as an intense heat source for joining two metals. This intense heat source has an exceptional capability to raise the material to virtually any temperature in an extremely short duration. Because of this unique property, EBW offers the following advantages:
r Joining dissimilar metals of largely varying melting points r Narrow and deep welds r Ability to join both thick and thin sections r Low heat-affected zone r Joining highly reactive metals r Filler-material-free weld
This chapter introduces the principle of EBW. The applicability of electron beams to both macro-and microwelding has also been discussed. Macro EBW technology was initiated mainly by the requirements of the nuclear and aeronautical industries and micro EBW by the micro electro mechanical systems (MEMS) and semiconductor industries. Assembly of miniature chemical test kits (micro total analysis systems) and joining of carbon nanotubes are some promising areas in which electron beam microwelding (EBmW) can be successfully applied. EBmW can be thought of as a scaled-down, high-precision version of the conventional EBW. EBmW machine development is expected to play a major role in realizing modern, cutting-edge technologies. However, the development of the EBmW machine has not yet fully matured, although the working principles of macro and micro EBW are the same. The following section gives a brief idea of conventional EBW machines before introducing some concepts of EBmW machines.
