Beryllium copper/palladium alloy electron beam welded sliding contacts
The advantages and process limitations of the latest generation of electron-beam-welded materials are reviewed. The study of metallurgical properties in the weld zone utilizes scanning electron microscopy and metallographic techniques. Various material and weld parameters are evaluated at they relate to final mechanical properties. The relationships of design criteria to metallurgical characteristics and to the effects of heat treatment are discussed.<<ETX>>
Electron-Beam Technology in Switch Contacts
The original concept was to develop a composite strip of material for switch contacts, such that the silver portion is suitably bonded to the base metal such as copper, phosphor bronze, or beryllium copper. The requirements were a metallurgically sound reproducible-nonporous uniform ductile bond. Electron-beam welding technology meets these requirements for joining switch contact materials. Fine silver, coin silver, silver cadmium oxide, and other wrought contact materials can be continuously electron-beam welded to the base metal switchblade member and then subsequently stamped and formed to the necessary switch configuration. This manufacturing technique is an improvement over the alternate joining methods of resistance welding, brazing, tungsten inert gas welding, thermocompression bonding, and the more recent laser welding.
On the ontology of particle mass and energy in special relativity
Einstein claimed that the fundamental dynamical insight of special relativity was the equivalence of mass and energy. I disagree. Not only are mass and energy not equivalent (whatever exactly that means) but talk of such equivalence obscures the real dynamical insight of special relativity, which concerns the nature of 4-forces and interactions more generally. In this paper I present and defend a new ontology of special relativistic particle dynamics that makes this insight perspicuous and I explain how alleged cases of mass–energy conversion can be accommodated within that ontology.