lect4-solidificationandprocessing

lect4-solidificationandprocessing - Lecture 4: Biomaterials...

Info iconThis preview shows pages 1–3. Sign up to view the full content.

View Full Document Right Arrow Icon
Lecture 4: Biomaterials Solidification and processing Last time, we looked at how atoms pack in metals  and ceramics. We also began to understand  polycrystalline materials and grain boundaries. We  noted that processing controls the density of grain  boundaries, and we began to talk about metal  processing, namely solidification which is a PHASE  TRANSITION. We ended by looking at MARTENSITIC PHASE  TRANSFORMATIONS. ABA ABC For phase transitions, like solidification, that aren’t spontaneous, one  has nucleation and growth. Solidification: Nucleation and Growth Nucleation.       How solidification starts. Gibb’s Free Energy 1 H L
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
G = D H - T D S For solidification, ∆H=-L The latent heat of fusion (liq solid) At T m , ∆G=0 ∆H-T∆S=0=-L-T∆S so that  S = - L T m For simplicity, ∆c p =0 (the heat capacity at constant pressure is  zero) G = - L + T L T m We apply a simple rearrangement and find that G = L T m T - T m [ ]
Background image of page 2
Image of page 3
This is the end of the preview. Sign up to access the rest of the document.

Page1 / 8

lect4-solidificationandprocessing - Lecture 4: Biomaterials...

This preview shows document pages 1 - 3. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online