Ceramics and Glass - C5 Flashcards
Glass has a r….. structure and is held by d…..l covalent bonds.
rigid, directional.
What plates are ceramics made up of?
Small crystalline plates.
What is monocrystalline?
A material made of one crystal.
What is polycrystalline?
A material made of many crystals.
In ceramics and glass, there are many g….s. Their arrangement is a…..s with random grain boundaries, but the crystals within each grain have c…..e structure.
Grains, amorphous, crystalline.
Describe how glass is formed…
Glass is heated then cooled quickly, trapping particles in an amorphous state.
Ceramics and glass have high s…..s. Ceramics can undergo lots of ….. deformation. There are no free e….. due to ionic and covalent bonds so they are insulators. They are non-c…..e
Stiffness, elastic, electrons, corrosive.
Why are glass and ceramics brittle?
Strong directional bonds mean atoms can’t slip.
Why do cracks propagate easily?
Defects deflect strains and these concentrate under cracks causing cracks to spread as bonds are broken.
Why are glasses and ceramics hard?
Particles are tightly bonded.
Glasses and ceramics have a high …. strength and low …. strength.
Compressive, tensile.
Ceramics have d….l covalent bonds. The bonds are strong so silica is ….., and the bonds are directional so ceramics are b….e and hard.
directional, stiff, brittle.
How are ceramics formed?
Water is added to clay before the ceramic is moulded and placed in a kiln to remove excess water.
