Fabrication of in situ TiC reinforced aluminum matrix composites

In the present work, the room and elevated temperature mechanical behavior of Al/TiC, high-strength Al-Si/TiC and the elevated temperature-resistant A l-Fe(-V-Si)/TiC composites has been evaluated. The microstructural characte ristics 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 re lated 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 e levated temperature tensile properties compared to those of rapidly solidif ied 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 i n keeping with the strong interfacial bonding. In the micromechanics approa ch, the principal strengthening mechanisms for the present dispersed partic le-hardened RS in situ Al-TiC composites would include Orowan strengthening , grain-size and substructure strengthening, and solid-solution strengtheni ng. The RS technique was used in the present work to maximize strength and ductility for a particular volume fraction, and influence the degree of fle xibility available to meet these requirements: a fine, uniform particle siz e distribution; a high interfacial strength; control of particle shape; and a ductile matrix. (C) 2001 Kluwer Academic Publishers.