Recrystallization of TiC dispersion Mo-alloy

Abstract

The recrystallization of Mo sheet which was mechanically alloyed with 1.0 TiC and 0.2 C (weight %) was investigated in H-2 atmosphere. The change in hardness (H nu) was measured as a function of annealing temperature and the microstructure was observed using scanning, transmission and Auger electron microscopy. H nu decreased slowly below 1800 degrees C and steeply above 1800 degrees C. Dislocations and grain boundaries were still pinned by small Ti-oxy-carbide and/or Ti-oxide particles even at 1800 degrees C, while the grain size increased. Above 1800 degrees C, however, such particles were coarsened with the formation of pores and also the grain size increased further. As a result, the slow drop phenomena of H nu below 1800 degrees C should be interpreted in terms of a retarding effect of fine particles on the recrystallization. The prominent drop phenomena of H nu over 1800 degrees C can be understood by the grain growth and particle coarsening accompanying an evolution of pores. (C) 1996 Elsevier Science Limited