Mechanical Engineering Faculty Research

Title

The Microstructure of a TiB2-B4C Ceramic Composite Synthesized by in-situ Displacement Reaction: Experimental Observations versus Numerical Predictions

Document Type

Conference Proceeding

Publication Date

2005

Abstract

The presence of boron carbide particles in a titanium diboride matrix was synthesized by a displacement reaction between titanium carbide (TiC) and elemental boron (B) using the technique of plasma pressure compaction. The residual stresses induced and present in the microstructure of the TiB 2-B4C composite upon cooling from the consolidation temperature were determined using finite element analysis. Two different geometries for the reinforcing boron carbide phase, i.e., the regular shape and irregular shape were chosen and examined. The influence of residual stress in promoting microscopic cracking at and along the grain boundary regions, at interfaces between the two phases and through the grain is rationalized. The presence and distribution of thermal residual stress in the microstructure of the ceramic composite can be satisfactorily predicted using the finite element method. The presence of boron carbide particles in the titanium diboride matrix causes a local elevation in stress levels, which is conducive for the initiation of fine microscopic cracks. The numerical results and interpretations accord well electron microscopy observations of the composite microstructure.

Publication Title

Materials Science and Technology