University of Illinois Urbana-Champaign

On the calculation of matrix-reinforcement interface diffusion coefficient in composite materials at high temperatures

Nimmagadda, Prasad B.R.; Sofronis, Petros

Permalink

https://hdl.handle.net/2142/112504

Description

Title
On the calculation of matrix-reinforcement interface diffusion coefficient in composite materials at high temperatures
Author(s)
  • Nimmagadda, Prasad B.R.
  • Sofronis, Petros
Issue Date
1995-08
Keyword(s)
  • Matrix-reinforcement Interface
  • Diffusion Coefficient
  • Composite Materials
  • High Temperatures
Abstract
Metal or intermetallic matrix composites reinforced with discontinuous fibers exhibit creep strength which is superior to the unreinforced matrix strength due to the constraint imposed by the fibers on the deformation of the matrix. However, experimental measurements indicate that at temperatures higher than approximately half of the melting temperature of the matrix the composite creep resistance is limited, and in some cases the strengthening imparted by the reinforcements is completely lost even when no damage accumulation or debonding occurs at the matrix/reinforcement interface. Slip of the matrix over the reinforcement or diffusional mass transport along the matrix/reinforcement interface have been shown to be possible mechanisms responsible for the loss of strengthening. Current model predictions for the effect of the diffusional relaxation mechanism are based on a diffusion coefficient for the mass transport along the matrix/reinforcement interface. This diffusion coefficient is unknown, hard to quantify and no experimental measurements exist. In this paper a methodology for the calculation of the interface diffusion coefficient is presented on the basis that long range diffusional mass transport occurs with free slip of the matrix over the reinforcement, and that diffusional relaxation is needed in addition to slip for the composite strength to be knocked down to levels around and below that of the pure matrix. The procedure combines experimental measurements of the composite creep strength as a function of applied strain rate and temperature along with corresponding strength predictions from finite element calculations.
Publisher
Department of Theoretical and Applied Mechanics. College of Engineering. University of Illinois at Urbana-Champaign
Series/Report Name or Number
  • TAM R 806
  • 1995-6028
ISSN
0073-5264
Type of Resource
text
Language
eng
Permalink
http://hdl.handle.net/2142/112504
Sponsor(s)/Grant Number(s)
National Science Foundation 95/08 MSS 92 10686 95/08
Copyright and License Information
Copyright 1995 Board of Trustees of the University of Illinois

Owning Collections

Technical Reports - Theoretical and Applied Mechanics (TAM) PRIMARY
TAM technical reports include manuscripts intended for publication, theses judged to have general interest, notes prepared for short courses, symposia compiled from outstanding undergraduate projects, and reports prepared for research-sponsoring agencies.