Material Science of Metal-Ceramics Flashcards
What are four mechanical properties of metal ceramics
mechanical
physical
chemical
biologic
What 5 things are involved with mechanical properties
ultimate strength yield strength modulus of elasticity elongation hardness
This component of dentin is higher than enamel
tensile strength
What 5 things are involved with physical properties
mass properties thermal properties electrical properties optical properties surface properties
What are the preparation specifications for an MCC
1.5mm axial reduction where you need esthetic looking porcelain
Why are alloys used for cast metal and metal-ceramic restorations
because metals in pure form are soft
What two mechanisms can be used to improve alloy mechanical properties
solid solution hardening
grain refining
Strengthening noble metals can be done what two ways
must be made to resist deformation
modified to impede dislocations
This of noble metals resists deformation; block dislocation movements
grain boundaries
Fine or Coarse structure resists deformation
fine
These two things are greatly improved with small grains
tensile strength and elongation
What two things affect the classification of casting alloys
noble metal content
hardness
What is the casting alloy classification scale, according to noble metal
very high (>80% gold) high (60->40% gold) noble metal (25%) no Au requirement predominately base metal (25%, no Au require.)
This is used at OSU for CVCs; type III (hard) yellow appearance; noble metal alloy
Midas
What two things do alloys allow that pure metals do not
improve mechanical and physical properties
improve metal-ceramic bonding
