Ceramics • Term ceramics comes from the greek word keramikos – “burnt stuff” • Ceramics are typically formed during high temperature heat treating – “Firing” • Traditionally ceramics included: • China • Porcelain • Bricks (both construction and refractory) • Tiles • Glasses • Over the last 60 years or so…there has been an explosion in new technologies similar to other areas of material science
19
Embed
Ceramics Term ceramics comes from the greek word keramikos – “burnt stuff” Ceramics are typically formed during high temperature heat treating – “Firing”
This document is posted to help you gain knowledge. Please leave a comment to let me know what you think about it! Share it to your friends and learn new things together.
Transcript
Ceramics• Term ceramics comes from the greek word keramikos –
“burnt stuff”
• Ceramics are typically formed during high temperature heat treating – “Firing”
• Traditionally ceramics included:• China• Porcelain• Bricks (both construction and refractory)• Tiles• Glasses
• Over the last 60 years or so…there has been an explosion in new technologies similar to other areas of material science
• Bonding: -- Mostly ionic, some covalent. -- % ionic character increases with difference in electronegativity.
• Amount of ionic bond character:
Ceramic Bonding
SiC: small
CaF2: large
Eq 2.10: % ionic character = {1 – exp[-(0.25)(XA – XB)2]} x 100
XA, XB are electronegativities of components A and B
Ionic Ceramics
• Crystal structure are composed of electrically charged ions– Cations (Fe3+) – Positive Charge Typically metals
– Anions (O2-) – Negatively Charged Typically non-metals
• Two characteristics influence crystal structure:– The magnitude of charge on the component ions