MATERIALS SCIENCE & ENGINEERING . Part of . A Learner’s Guide. AN INTRODUCTORY E-BOOK. Anandh Subramaniam & Kantesh Balani Materials Science and Engineering (MSE) Indian Institute of Technology, Kanpur- 208016 Email: [email protected], URL: home.iitk.ac.in/~anandh.
& their distribution
Processing determines shape and microstructure of a component
Let us start with a cursory look at the lengthscales involved in Materials Science
Dislocation Stress fields→ Nanometers
(Notes in the next slide)
*Simple Unit Cells
Unit cells of simple crystals are a few angstroms (though there might be crystals with large unit cells– examples of these may be found in Chapter 4)
The next few slides takes the reader across multiple lengthscales- considering various properties
Some of the terms and concepts introduced are very advanced for a beginner. The reader may take a cursory glance in the first instance and may return to these slides at a later stage in the course
Change of properties across lengthscales: polycrystalline copper (CCP structure)
Atomic level (Å) → Unit Cell level (few Å-nm)→ Grain level (nm-m) → Material level (cm)
Traversing four lengthscales in a Cu polycrystal: schematic of the changing order and properties. a) instantaneous snapshot of a vibrating atom, b) crystalline order (unit cell), c), grain level (single crystal- anisotropy) , d) the material level (isotropy due to randomly oriented grains).
Change of properties across lengthscales: Fe sample which has not been magnetized
Atomic level (Å) → Domain level (~fewm) → Material level (cm)
The Gear wheel