DIFFUSIONAL PRESTRESSING OF CERAMICS.
Abstract
This report describes an investigation concerning diffusional prestressing of magnesia single crystal tensile specimens. Compressively stressed surface layers were obtained by creating a solid solution of MgO and NiO at the periphery of the specimen. This solid solution possesses a lower coefficient of expansion than the host MgO crystal and acquires a residual stress during cooling from the diffusion anneal temperature. The potential strength enhancement is discussed and an estimation of the magnitude of the effect is given. Several systems were examined with respect to the adaptability to this program. The effect of concentration of solute on the thermal expansion of magnesia solid solutions was investigated. Solute oxides included NiO, MnO, CaO, Li2O, and BeO. The quality of the solid solutions was evaluated by determining by X-ray lattice parameters, and thermal expansion was measured by high temperature X-ray diffraction. The current status of the work indicates that only the MgO-NiO system is suitable for the mechanical portion of this program.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jul 06, 1967
- Accession Number
- AD0819014
Entities
People
- Herbert P. Cox
- Robert D. Hurst
- Roy E. Bickelhaupt
Organizations
- Southern Research