Mechanical instabilities of metals Temperature changes during deforrnotion are indices of fundamental processes

Authors

  • CARLO E. BOTTANI
  • GIUSEPPE CAGLIOTI

Abstract

ln the general context of the non-.linear thermodynamics of irreversible phenomena, the.thermoelasioptastic between transition occurring at the boundary the thermoelastic and thermoplastic régimes of deformation br m"ta,ttic À"terials can be seén as a bifurcation point. This non-equilibrium phase transformation is detected by measuing lhe rcmperature changes in a sample unaergoiij àefo,r;;i;;, since these are indices of fundamental processes" initial cooiingunderaÚiabaticconditionsdueíothethirÀiaelastice"fferítLorakitini,'185' )issuddentyfollowedbyarise il.r?!!?,::yn cau2_e-( bv entropy próduction in the highty irreversitte tnerÀiItastìc regime beyoìna tÀe niriícation. tnermal emtsston (l E) at and.beyond yielding can also be usefully exploited, tógether,ilith acoústic emiisiotn-if required, in the investigation of thermodynamic transformations or mechanlcal instabilities durin'g *nirn m,ecn'anìiat *ork is converted into thermal energy, as in creep, fatigue and fracture, for example.

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Published

2013-08-08

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Articles