On. Senkov et al., Synthesis and characterization of a TiAl/Ti5Si3 composite with a submicrocrystalline structure, MAT SCI E A, 300(1-2), 2001, pp. 85-93
A Ti-47Al-3Cr/Ti5Si3 composite with a submicrocrystalline structure was pro
duced by mechanical alloying (MA) and hot isostatic pressing (HIP). Blends
of elemental and pre-alloyed powders were used for the MA, Intimate mixing
of the elements and powder amorphization occurred during MA. HIP of the MA
powder resulted in a fully dense material with a submicron grain size and a
homogeneously distributed mixture of gamma-TiAl and Ti5Si3 grains. The ave
rage grain size increased from 140 to 540 nm when the HIP temperature was i
ncreased from 850 to 1050 degreesC. Grain growth in the composite in the te
mperature range 850-1100 degreesC was described by the equation D-4 - D-o(4
) = K-o exp(- Q/RT)t where Q = 330 kJ mol(-1) and K-o = 3.0 x 10(-18) m(4)
s(-1). The kinetic behavior was similar to that for a nanocrystalline Ti-47
Al-3Cr alloy annealed in the same temperature range, i.e. the Ti5Si3 phase
had little effect on grain growth. (C) 2001 Elsevier Science B.V. All right
s reserved.