Lecture13-Notes - ME 382 Lecture 13 1 E FFECTS OF ALLOYING...

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

View Full Document Right Arrow Icon

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

View Full DocumentRight Arrow Icon
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: ME 382 Lecture 13 1 E FFECTS OF ALLOYING ON YIELD STRENGTH 1. Solid-solution hardening • Occurs with interstitial solid solutions or with substitutional solid solutions • Local compressive stress field around interstitial solute atoms • Local stress field when substitutional solute atom is different size from solvent atoms • Example: Bronze consists of Sn dissolved in Cu • Sn atoms larger than Cu • Stress field interacts with stress field of dislocation • Dislocation line distorts to minimize energy (at cost of extra length) ME 382 Lecture 13 2 • This is minimum energy position ∴ Extra work is needed to move the line from this configuration • Shear strength is given by: k shear strength ∝ ε m 3/ 2 misfit strain × c concentration • Increase concentration above equilibrium (supersaturated solution) for enhanced σ Y 2. Precipitation hardening Coherent or semi-coherent precipitates • If small precipitates develop they will generally have a mismatch strain with matrix (Coherent or semi-coherent pttes. have some lattice alignment with host) • Strengthening mechanism similar to solid-solution hardening...
View Full Document

This note was uploaded on 09/08/2011 for the course MECHENG 382 taught by Professor Thouless during the Fall '08 term at University of Michigan.

Page1 / 5

Lecture13-Notes - ME 382 Lecture 13 1 E FFECTS OF ALLOYING...

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