Length and density changes of amorphous Pd40Cu30Ni10P20 alloys due to structural relaxation

The density changes of bulk amorphous Pd₄₀Cu₃₀Ni₁₀P₂₀ due to structural relaxation under isothermal heat treatment were measured using the buoyancy method. The corresponding length changes of amorphous Pd₄₀Cu₃₀Ni₁₀P₂₀ ribbons applying non-isothermal heat treatment are determined applying dilatometry. The measured density changes Δρ(T=const.,t)/ρ_o as a function of isothermal heat treatment increase close to the glass transition up to 0.18%. The measured density changes as a function of temperature and time are furthermore reversible. The experimental data validate the model predictions of the free volume model for length and density changes of amorphous alloys due to structural relaxation applying isothermal and non-isothermal heat treatment.