Precipitation hardening of Infrared Transmitting ZnS Ceramics
Abstract
Precipitation strengthening is a potential technique for hardening and toughening infrared transmitting materials. The controlled precipitation of a fine dispersion during second phase offers the opportunity to improve mechanical properties without degrading optical properties. It is well established that the presence of an appropriate dispersion of second phase particles can improve the mechanical behavior of ceramics, and, by maintaining a particle size <100 nm, scattering losses in the infrared will be low and the need to index-match zinc sulfides matrix with the second phase will be circumvented. Overall objectives of the research have been: (1) to demonstrate that ZnS-based ceramics can be precipitation-strengthened and (2) to characterize the resulting mechanical properties and optical properties of the multiphase materials. An important research goal has been to identify ZnS-based systems suitable for strengthening and to determine composition ranges and annealing treatments required to produce precipitate phases or other solid state reaction products. Another research objective has been to determine why 'alloys' in the ZnS gallium sulfide system exhibit an increase in both fracture toughness and hardness, and to establish the composition ranges and annealing treatments which produce this behavior.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jun 30, 1991
- Accession Number
- ADA238839
Entities
People
- Alan Ardell
- Bruce Dunn
Organizations
- University of California, Los Angeles