Processing Flashcards
Different classes of materials and how they can be processed
Why can’t ceramics be readily cast?
Have very high melting points due to ionic bonding
Why can’t ceramics be readily plastic deformed?
Is brittle rather than ductile due to ionic bonding
How are ceramics shaped?
Using powder processing approach: reduced to powders, moulded into required shape, and heated; powders sinter (bond together) to form dense product with the necessary properties
How are ceramics able to be treated like liquids?
By suspending ceramic particles in a slurry, pouring into mould, and carrier liquid being drawn off - leaves a viscous layer at the surface of the mould, which can be removed to be fired or sintered
How does sintering affect microstructure?
Has a varying effect on the removal of the pores that are naturally occurring between the powder particles
What is a composite?
Consists of mixtures of different materials: reinforcement within a matrix of metals, polymers, or ceramics; new material has mixture of properties derivative of constituent materials
What is glass-reinforced plastic?
Matrix of resin into which glass fibres are mixed
What are metal-matrix composites?
Mixture of ceramic particles in a metal matrix
How are metals processed?
Rolling, casting (melting + moulding), forging (application of force), extrusion (forced through a die to form a new cross-section), drawing (to make cup-shaped objects), machining (shearing away pieces of metal), welding (forming single component from molten metals)
How does processing metals cause changes in microstructure?
Often involves heating, which often cause phase changed, altering microstructure and thus strength
How are polymers processed?
Normally through extrusion, but there are analogous processes for rolling, forging, machining, and welding
How does processing polymers change their mechanical properties?
Can change amount of crystallinity, altering strength
