Şekil Hafıza Davranışlarının Termodinamiği

Yıl 2018, Cilt: 21 Sayı:1, 201 - 211, 31.03.2018

Emre Acar , Murat Aydın

https://doi.org/10.2339/politeknik.386895

Öz

Akıllı malzemeler bugünkü
teknolojik uygulamalarda önemli bir yer tutmaktadır. Metalik akıllı malzemeler
olan şekil hafızalı alaşımlar ise yüksek dayanım ve fonksiyonel özellik
gerektiren uygulamalarda kullanılma potansiyeline sahiptir. Şekil hafızalı
alaşımların sıradışı özellikleri, termo-elastik martenzitik faz dönüşümlerinden
kaynaklanmaktadır. Bu çalışmada, termo-elastik martenzitik faz dönüşümleri
konusunda yapılmış çalışmalarda kullanılan termodinamik teorileri, denge
termodinamik teorisi ve fenomolojik termodinamik teorisi olarak iki ana başlık
altında incelenmiştir. Daha sonra şekil hafızalı alaşımların dönüşüm
sıcaklıkları ve ısıları termodinamik formüller ile ifade edilmiştir. Son olarak
ise şekil hafızalı alaşımların davranışları genelleştirilmiş termodinamik
teorileri ile açıklanmıştır. 

Anahtar Kelimeler

Şekil hafızalı alaşım, termodinamik, faz dönüşümü

Thermodynamics of Shape memory Behaviours

Öz

Smart materials play important roles in today’s
technology. Shape memory alloys are metallic class of smart materials and they
have promising potentials in applications that require high strength and
functionality. The origin of the unusual properties of shape memory alloys is
thermo-elastic martensitic phase transformation. In this study, thermodynamic
theories used in analyzing the thermo-elastic martensitic phase transformations
are reviewed by considering equilibrium thermodynamic theory and phonemenological
thermodynamic theory. Then, transformation temperatures and heats are expressed
by thermodynamic equations. Finally, shape memory behaviors are investigated by
generalized thermodynamic theories.

Anahtar Kelimeler

Shape memory alloy, thermodynamics, phase transformation

Kaynakça

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