Pii: S1359-6454(99)00214-1

ÐSamples of superelastic NiTi and superelastic NiTi reinforced with 10 vol.% TiC particles were deformed under uniaxial compression to 975 MPa while neutron di€raction spectra were simultaneously collected. Despite the presence of sti€ TiC particles, a macroscopic strain of 3% was obtained in the composite on loading and was fully recovered on unloading. The di€raction spectra were analyzed by Rietveld re®nement that included a spherical harmonic description of the texture and a lattice plane (hkl) dependent formulation of the elastic strain. The experiments provided bulk, phase-speci®c measurements of the evolution of phase fractions, texture and strains during the reversible stress-induced austenite to martensite transformation responsible for the large recoverable strains. For the composite, Eshelby elastic theory is used to predict the discrete phase strains measured by neutron di€raction. The observed behavior suggests that the martensite accommodates the mismatch with the transforming austenite (while they co-exist) and the TiC particles (in the case of the composite). # 1999 Acta Metallurgica Inc. Published by Elsevier Science Ltd. All rights reserved.