Kuz'menko M. Development of thermal deformed titanium composites of Ti-Si-(Al,Zr) system as structural materials working within 20-700 оС temperature range

The research objectives are processes of structure formation in as-cast and thermomechanical processed Ti-Si and Ti-Si-(Al,Zr) alloys as well as their physico-mechanical properties in temperature range 20-700 оС. The goal is an elaboration of novel silicon-strengthened titanium-based alloys and optimization of their hot pressing conditions. Research methods are structural analysis (SEM with SUPERPROBE 723 and Т-20, "Jeol", Japan), X-ray phase analysis, differential thermal analysis, measurements of microhardness aned lond-term hardness, mechanical tests under tension, 4-point bending and uniaxial compression. registration facility). The work novelty is in revealing of regularities of temperature and deformation power effect on structure and mechanical properties of Ti-3Al-5Zr-хSi titanium-based composites containing 2, 4 and 6 wt. % in temperature range 20-700 oC?. Firstly established in the work is transformation of (Ti,Zr)5(Al,Si)3 silicide phase to (Ti,Zr)2(Al,Si) in copmlex-alloyed Ti-Si-(Al,Zr)alloys at thermomechanical processing. An optimal silicon content 1.3-2.0 wt. % in as-deformed Ti-Si-(Al,Zr) composites was found to result in obtaining enhanced room temperature ductility and high temperature strength. Thermomechanical processing effect in various phase regions on characteristics of strength and ductility of partially stabilized alloy Ti-8Al-1,4Si-2,2Zr at room and elevated temperatures is established too. Practical significance of the work is an elaboration of recommendations for manufacturing Ti-Si-(Al,Zr)-based details chracterized by high specific strength, fracture toughness and high temperature strength capable to work in temperature range 20-700 oC. The internal-combustion engine details manufactured of Ti-Si-(Al,Zr) alloys have resulted in growth of engine performance characteristics. The scientific results obtained were used also as a basis in manufacturing biomedical test samples of hip joint femoral head.