Fabrication of in situ TiC reinforced aluminum matrix composites

摘要

In the present work, the room and elevated temperature mechanical behavior of Al/TiC, high-strength Al-Si/TiC and the elevated temperature-resistant Al-Fe(-V-Si)/TiC composites has been evaluated. The microstructural characteristics of ingot metallurgy (IM) or rapid solidification (RS) Al-Si/TiC and Al-Fe(-V-Si)/TiC composites could be thought of as a combination of the related alloy matrix microstructures and the IM or RS Al/TiC composites. The IM Al/TiC and the Al-Si/TiC composites show superior strength and ductility to the relevant aluminum based composites. The RS Al/TiC and the Al-Fe-V-Si/TiC exhibit high Young's moduli and substantial improvements in room and elevated temperature tensile properties compared to those of rapidly solidified alloys and conventional composites. The Young's modulus values of RS Al/TiC and Al-Fe-V-Si/TiC composites are well within Hashin-Shtrikman limits in keeping with the strong interfacial bonding. In the micromechanics approach, the principal strengthening mechanisms for the present dispersed particle-hardened RS in situ Al-TiC composites would include Orowan strengthening, grain-size and substructure strengthening, and solid-solution trengthening. The RS technique was used in the present work to maximize strength and ductility for a particular volume fraction, and influence the degree of flexibility available to meet these requirements: a fine, uniform particle size distribution; a high interfacial strength; control of particle shape; and a ductile matrix.