Methods for consolidation and densification of fibrous monolith composite structures are provided. Consolidation and densification of two- and three-dimensional fibrous monolith components having complex geometries can be achieved by pressureless sintering. The fibrous monolith composites are formed from filaments having at least a first material composition generally surrounded by a second material composition. The composites are sintered at a pressure of no more than about 30 psi to provide consolidated and densified fibrous monolith composites.
 This invention was made with U.S. Government support under grant Number DE-FC02-96CH10861 awarded by the Department of Energy, under grant Number NAS8-00081 awarded by the National Aeronautics and Space Administration, and under grant number DASG60-01-P-0050 awarded by the U.S. Army Space and Missile Defense. Accordingly, the Government may have certain rights in the invention described herein.