Processing of Advanced Materials with a High Frequency, Millimeter-Wave Beam Source and Other Microwave Systems

摘要

An 83 GHz gyrotron-based, millimeter-wave beam system is being used in material processing: in rapid sintering of oxides, ferrites, and metal-ceramic composites to retain very fine grain structure in the product for improved mechanical and electromagnetic properties; in joining of ceramic and ceramic composite materials (with unique advantages- localization of heating, permitting inexpensive fixturing and instrumentation and minimizing thermal damage to components; depositing energy specifically in a narrow joint region through a guided wave effect), and in coating densification and coating removal where the high frequency and short wavelength permit significant energy deposition in relatively thin coatings. In a related effort, we are using a low frequency microwave system for low cost continuous production of nanophase metals. This process should produce a range of nanophase metals, metal oxides and mixtures of these, in sizeable quantities and at low cost. The results of various experiments in these areas will be discussed, as will the potential of low and high frequency microwave processing of advanced materials.