PHYSICAL AND MECHANICAL-PROPERTIES AND THE STRUCTURE OF AS-QUENCHED TI-NI-AL ALLOYS

The dependence of the modulus of normal elasticity E, shear modulus G, and logarithmic damping coefficient Q on the concentration and struct ure of as-quenched alloys of the system Ti - Ni - Al with 2 to 15 wt.% Al and 10 to 16 wt.% Nb are investigated (here and henceforth, concen tration is given in weight %). The alloys with the martensite alpha' ( alpha'')-phase structure display high damping properties. The beta-pha se considerably deteriorates these properties. Addition of Al up to 3% expands the existence region of alloys with alpha' and alpha'' struct ures. At Al content above 5%, stabilization of the structure and the a ppearance of the metastable beta-phase with lower Nb content are obser ved. The omega phase is detected by X-ray diffraction only in alloys w ith 24% Nb and 2 to 5% Al.