HEAT TREATMENT BY PLASMA ELECTRON HEATING AND SOLID/GAS JET COOLING

摘要

A workpiece (44) is heated by first forming an ionized gas plasma (38) around the workpiece (44). A positive potential is applied to the workpiece (44) to accelerate electrons from the plasma (38) into the workpiece (44). The workpiece (44) is uniformly surface heated by the energy directed into the workpiece (44) by the electrons. The workpiece (44) is cooled by providing a flow of a pressurized liquid material such as carbon dioxide having a triple point. The liquid material is expanded through a nozzle (62) to form solid particles (70) that contact the surface of the workpiece (44) and remove heat from it by sublimation.