Internal friction and shear modulus of certain metallic glasses

We have measured the temperature dependence of the internal friction and shear modulus of metallic glass alloys Fe₄₀Ni₄₀P₁₄B₆, Fe₂₉Ni₄₉P₁₄B₆Si₂, Fe₈₀B₂₀ and Fe₇₈Mo₂B₂₀ in the glassy and crystalline phases using a torsional pendulum technique. The internal friction in the glassy phase remains approximately constant from room temperature to a temperature which depends on the annealing treatment, and the rises exponentially with temperature. The internal friction measurements were made at two different frequencies (0.2 Hz and 1.0 Hz) and the activation energies for the relaxation processes estimated by the frequency shift method. The shear modulus increases by about 30% when the amorphous alloys are crystallized. The amorphous alloys Fe₈₀B₂₀ and Fe₇₈Mo₂B₂₀ exhibit Invar type behaviour which disappears upon crystallization.