Calorimetric investigation of order-disorder transition in Cu _(0.6)Pd_(0.4) and Cu_(0.85)Pd_(0.15) alloys

摘要

Order-disorder phase transitions in Cu_(0.6)Pd_(0.4) and Cu_(0.85)Pd_(0.15) alloys have been investigated using differential scanning calorimetry and drop calorimetry. The differential scanning calorimetry measurements show that the transition in both these alloys are reversible in nature and the enthalpy increment measurements reveal that these transitions are first order in nature. The transition temperature of first-order phase transition in Cu_(0.6)Pd_(0.4) and Cu _(0.85)Pd_(0.15) alloys have been evaluated to be 884(±2) and 799(±2) K, respectively, from drop calorimetric measurements. The latent heat of first-order phase transition in Cu_(0.6)Pd_(0.4) alloy were evaluated to be 31.2(±0.6) and 28.9(±0.5) J g -1, by enthalpy increment and differential scanning calorimetry measurements, respectively. Similarly, the latent heat of first-order phase transition in Cu_(0.85)Pd_(0.15) alloy were evaluated to be 23.1(±0.6) and 21.3(±0.5) J g~(-1), by enthalpy increment and differential scanning calorimetry measurements, respectively. The solidus temperatures of Cu_(0.6)Pd_(0.4) and Cu_(0.85)Pd _(0.15) alloys were found to be 1,457(±2) and 1,360 K, respectively.