Effect of Deformation Processing on Mechanical Properties of Nb-10 a/o Si In-situ Composite

Document Type

Conference Proceeding

Publication Date



Nb-10 a/o Si alloy is an in-situ composite. The microstructure of the cast alloy consists of pro-eutectic Nb dendrites distributed in a matrix of eutectic Nb3Si + Nb phases. The microstructure of the as-cast alloy was modified by multiple hot extrusions producing an oriented composite. Extensive grain size refinement occurred in both the Nb and Nb3Si phases. The ductile primary (pro-eutectic) Nb particles were aligned along the extrusion direction. Bend strength and fracture toughness measured by three point bend and four point bend tests, respectively, showed that both the yield strength and fracture toughness of the alloy increases considerably following this thermomechanical processing. These improvements have been attributed to the changes in size, morphology and spacing of the constituent phases and their microstructural refinement.


Presented at Symposium F on High Temperature Silicides and Refractory Alloys, held in conjunction with the 1993 Fall Materials Research Society (MRS), Boston, MA.

Copyright © Materials Research Society 1994.