Surface Hardening with LAPPS
Abstract
LAPPS (Large Area Plasma Processing System) was invented in NRL's Plasma Physics Division and Materials Science and Technology Directorate. It uses a 2-5 keV electron beam to ionize and dissociate gas molecules, species that are then used to modify the surface properties of various materials. This novel approach to plasma generation provides a direct scalability of the system and higher control over reactive chemical species compared to conventional plasma processing systems used in the semiconductor and coatings industries. The scalability is simply dictated by the dimensions of the electron beam, allowing unprecedented surface areas to be treated uniformly. The process/chemical control is provided by the electron beam/molecule interactions, which ensures that all chemical reaction pathways are accessible, as opposed to conventional plasma systems. The ability to increase the hardness of a material while preserving its intrinsic properties provides tremendous advantages in choosing materials for demanding applications. Thin layers of well-known hard coatings are frequently used, but adhesion problems (lattice and temperature coefficient matching) limit their utility. For metals, incorporating nitrogen into the surface's lattice (surface nitriding) is highly desirable because the nitrided layer is physically part of, yet significantly harder than, the bulk material. Equally important in surface nitriding is maintaining sufficiently low temperatures to preserve the properties of the bulk material.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jan 01, 2005
- Accession Number
- ADA523043
Entities
People
- Christopher Muratore
- D. Leonhardt
- Robert A. Meger
- Scott G. Walton
Organizations
- United States Naval Research Laboratory