Process Relationship as Influenced by Carbonization Rate
Abstract
The typical process cycle for a carbon-carbon composite begins with an organic matrix impregnated fibrous preform cured according to conventional composite practices (e.g., lay-up, bagging and autoclave cure; hot pressing; etc.). This cured composite is then subjected to a pyrolysis cycle in the absence of oxygen which results in the carbonization of the matrix. Carbonization cycles are carried out to temperatures of 650-800 deg C for several hours or even days. During these cycles as much as 50% of the matrix mix can be volatilized with simultaneous shrinkage and microcracking. The resultant porous, low density carbonaceous solid is usually densified by additional matrix impregnation and heat treatment steps. The extreme length of the carbonization process is due to the heating cycle development methodology. The development of the material properties was not understood, so to deep catastrophic defects from occurring, the heating cycle was made very low. To intelligently control the process, the materials process/property relationship must be understood. In this study the relationship between heating rate and physical development of the carbonization of a phenolic preform was investigated.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jun 01, 1993
- Accession Number
- ADA269680
Entities
People
- David P. Anderson
- Kristen M. Kliner
- Timothy D. Naughton