Accession Number:

ADA235031

Title:

Pressureless Densification of Ceramic Matrix Composites

Descriptive Note:

Annual rept. Mar 1990-Feb 1991

Corporate Author:

MISSOURI UNIV-ROLLA

Personal Author(s):

• Rahaman, M. N.
• Dharani, L. R.
• Moore, R. E.

Report Date:

1991-03-22

Pagination or Media Count:

83.0

Abstract:

In the first reporting period, experimental and theoretical studies were performed to determine the effect of key material and processing parameters on the sintering of model ceramic composites. Experimentally, the effect of coarse inclusions Zirconium oxide on the sintering of a fine-grained matrix Zinc oxide was highly dependent on the forming method. Kinetic data and microstructural observations indicated that the main factors controlling sintering were the packing of the matrix immediately surrounding the inclusions and interactions between the inclusions. A forming method for alleviating these two problems was investigated. Using this method, composites with up to 35 V inclusions were sintered to full density under identical conditions used for the pure matrix. Theoretically, a finite element program was developed to describe the kinetic data over the entire sintering process. Transient stresses were calculated incrementally from the density-time data and used to predict the reduction in the sintering rate. The effects of single and multiple inclusions and heterogeneity in the matrix density were calculated.

Descriptors:

• *MATRIX MATERIALS
• *SINTERING
• *CERAMIC MATERIALS
• EXPERIMENTAL DATA
• MICROSTRUCTURE
• MODELS
• PARAMETERS
• MATERIALS
• PROCESSING
• COMPOSITE MATERIALS
• FINITE ELEMENT ANALYSIS
• THEORY
• RATES
• ZINC OXIDES
• PRESSURE
• KINETICS
• POWDER METALS
• ZIRCONIUM OXIDES
• DENSITY
• TRANSIENTS
• STRESSES
• MATHEMATICAL MODELS

Subject Categories:

• Ceramics, Refractories and Glass
• Laminates and Composite Materials

Distribution Statement:

APPROVED FOR PUBLIC RELEASE