3.1 The property relation S.J.T.U. Phase Transformation and Applications A closed system consisting of a homogeneous material with uniform properties throughout First law:dU =80+oW Second law:ds= 80 w T T Tds 80-8lw dU Tds +SW Slw Tds +8Wrer All the work terms: dU=Tds-PdV Surface,electrical,stress effects,etc dH Tds+VdP SJTU Thermodynamics of Materials Fall 2018 ©X.JJin Lecture 5 property relation
Phase Transformation and Applications S. J. T. U. SJTU Thermodynamics of Materials Fall 2018 © X. J. Jin Lecture 5 property relation 3.1 The property relation A closed system consisting of a homogeneous material with uniform properties throughout. First law: dU = Q +W Second law: T lw T Q dS = − TdS = Q −lw TdS Wrev dU = TdS +W +l w = + All the work terms: Surface, electrical, stress effects, etc dU =TdS − PdV dH =TdS +VdP
3.2 The Functions F and G(1) S.J.T.U. Phase Transformation and Applications F:the Helmholtz free energy G:the Gibbs free energy Measures of the work required to change a system from one state to another. dU =Tds +oWrev Integrating at constant temperature We,=△U-TAS=△U-△(TS)=A(U-TS) U-TS is defined as the Helmholtz free energy F =△F SJTU Thermodynamics of Materials Fall 2018 ©X.J.Jin Lecture 5 property relation
Phase Transformation and Applications S. J. T. U. SJTU Thermodynamics of Materials Fall 2018 © X. J. Jin Lecture 5 property relation 3.2 The Functions F and G (1) F: the Helmholtz free energy G: the Gibbs free energy Measures of the work required to change a system from one state to another. dU = TdS +Wrev Integrating at constant temperature W U T S U (TS) (U TS) rev = − = − = − U-TS is defined as the Helmholtz free energy F Wrev = F