Structure and physicomechanical properties of eutectic Ti-Si-X alloys

We study the structure and physicomechanical properties of various eutectic alloys of Ti-Si-Zr, Ti-Si-B, and Ti-Si-Ga systems. It is shown that Ti-Si-Zr alloys with elevated concentrations of Zr reveal, due to the presence of (Ti, Zr)₂ Si dispersed silicides with sizes of about several hundred nanometers, improved mechanical properties as compared with the properties of alloys based on Ti₅Si₃ silicides. The cast eutectic alloy of the Ti-Si-Zr-Sn system with a plasticity of ∼ 1.7% is obtained for the first time. The formation of superfine eutectics based on the Ti₆Si₂B ternary compound in alloys of the Ti-Si-B system enables one to obtain titanium composites with improved refractory properties and elevated moduli of elasticity (of about 150 GPa or, after additional alloying, as high as 165 GPa). This can be promising for the development of new refractory titanium composite materials with elevated stiffness. The analysis of the combined effect of gallium and silicon in Ti-Si-Ga alloys reveals the possibility of getting titanium materials with high heat resistance, i.e., materials based on the (α-Ti(α₂-Ti₃Ga) + Ti₅ (Si, Ga)₃ binary eutectics. Translated from Fizyko-Khimichna Mekhanika Materialiv, Vol. 44, No. 3, pp. 35–42, May–June, 2008.