Dissemination of IT for the Promotion of Materials Science (DoITPoMS)

DoITPoMS Micrograph Library Micrograph 593 and full record

Micrograph 593 and full record

Link to image file for micrograph 593
Micrograph no
593
Brief description
Ductile tearing near a fracture surface in polycarbonate
Keywords
craze Link to MATTER Glossary entry for craze, ductile Link to MATTER Glossary entry for ductile, ductile tearing, fibril Link to MATTER Glossary entry for fibril, fracture Link to MATTER Glossary entry for fracture, polycarbonate (PC), polymer Link to MATTER Glossary entry for polymer
Categories
Fracture, Polymer
System
Polycarbonate (PC)
Composition
Not specified
Standard codes
Reaction
Processing
Applications
Polycarbonate is a clear and relatively tough plastic used to make shatterproof windows, lenses and even helmets. It is also used to make compact discs.
Sample preparation
To induce crazing and fracture in polycarbonate, acetone is used. This results in the otherwise tough material becoming very brittle
Technique
Scanning electron microscopy (SEM)
Length bar
100 μm
Further information
The fracture surface is dominated by ductile tearing, and also shows linear voids with fine transverse filaments. These are the remnants of crazes which act both as a precursor to cracking and as a toughening mechanism. In some areas, more angular brittle fracture surfaces are also apparent. The fine-scale ridging of the surface, parallel to the principal stress direction (which is approximately vertical) morphology is the result of fibrous crystals being induced by cold-drawing.
Contributor
J A Curran
Organisation
Department of Materials Science and Metallurgy, University of Cambridge
Date
03/10/02
Licence for re-use
Attribution-NonCommercial-ShareAlike 4.0 International
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