Concurrent with an investigation of quaternary cast and forged L1(2) modified Al-3 Ti’s containing 9 at% Cr, Fe and/or Mn, a similar series of four alloys was produced via XD(TM) technology, whereby 20 vol% of similar to 0.5 mu m TiB2 particles was incorporated as a reinforcement. Following densification by hot pressing and slow isothermal forging, small diameter compression test samples were machined from each compact and tested. The 0.2% yield strength measurements revealed a strength advantage for the particulate reinforced materials over the unreinforced ingot metallurgy matrices to about 1175 K. Furthermore, 900 and 1100 K constant velocity testing indicated that the TiB2 containing materials were stronger than the ingot metallurgy matrices down to strain rates of similar to 10(-7)s(-1). None of the quaternary L1(2) alloys + 20 TiB2 consistently displayed a strength advantage over others. However, extrapolation of the present mechanical property data into slower strain regimes indicated that the composites will not possess any strength advantage over the unreinforced versions. Such losses in strength appeared to be caused by small grains in the particulate reinforced alloys, which promoted grain boundary weakening mechanisms.