Accession Number:

ADA238839

Title:

Precipitation hardening of Infrared Transmitting ZnS Ceramics

Descriptive Note:

Final technical rept. May 87-Oct 90,

Corporate Author:

CALIFORNIA UNIV LOS ANGELES DEPT OF MATERIALS SCIENCE AND ENGINEERING

Personal Author(s):

Report Date:

1991-06-30

Pagination or Media Count:

49.0

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.

Subject Categories:

  • Industrial Chemistry and Chemical Processing
  • Ceramics, Refractories and Glass
  • Optics

Distribution Statement:

APPROVED FOR PUBLIC RELEASE