CERTAIN PHYSICAL PROPERTIES OF TRANSITION METAL ALLOYS
DE CAMARGO, PAULO CESAR
Doctor of Philosophy
The linear coefficient of thermal expansion of Nb-Mo alloys was measured and its correlation with the anomalous behavior of the elastic constant C(,44) is discussed. The coincidence of the anomaly near the critical composition of 40% Mo is made evident. The Gruneisen parameters, both at low-temperature and high-temperature, are calculated and compared to the values of the Gruneisen parameters, obtained from the pressure derivative of elastic constants. The floating-zone technique, using a combination of R.F. induction and resistance heating, was successfully used to make large single crystals of Chronium-rich Vanadium alloys. The elastic constants C(,11) and C(,44) of Chromium alloys containing 0.67% and 1.5% Vanadium were determined by the pulse-superposition method. C(,12) was evaluated from smooth curves drawn as a function of temperature for C(,11) and C'. The addition of Vanadium to Chromium lowers both Neel and spin-flip temperatures drastically. The sharp minimum in the elastic constant C(,11) in Chromium is diminished by the addition of Vanadium. The effect of magnetic transition on the shear constants is extremely small. The high attenuation observed in Chromium at T(,N) virtually vanishes as a result of alloying with Vanadium.
Engineering; Materials science