Metal Properties Flashcards
What is osteosynthesis?
internal fixation of a bone fracture
What is the purpose of a joint replacement?
a full or partial replacement to increase joint junction
Why are spine implants special?
They differ in orientation and have a different tissue structure
What are examples of metal materials for implants?
Stainless Steel
Titanium-based alloys
Cobalt alloys
What are alloys?
metallic compounds made up of one or more metal or non-metal elements, can be stronger, have difference stress-strain properties, interact with biological systems
Describe alloy composition
Base - primary metal in the alloy, also known as the matrix or solvent
Solutes - the secondary molecules
Can be binary, tertiary, or quaternary, etc.
What is a substitutional alloy?
retains a similar crystal structure to the base, alloy atoms are similar in size
What is an interstitial alloy?
when an atom cannot “fit in” to the matrix
What are the physical properties of metals?
luster good conductors of heat and electricity high density high melting point ductile (drawn out into wires) malleable (hammered into thin shapes
What makes up Stainless Steel?
Iron - 62% Chromium - 18% Nickel - 16% Molybdenum - 3% Carbon - <1%
Advantages of Stainless Steel?
strong, ductile, biocompatible, relatively cheap
Disadvantages of Stainless Steel?
susceptible to crevice and stress corrosion
What makes up Titanium Alloys?
Titanium - 89%
Aluminum - 6%
Vanadium - 4%
Others - 1%
Advantages of Titanium Alloys?
Corrosion resistant
Excellent biocompatibility
Ductile
MR scan compatible
Disadvantages of Titanium Alloys?
Notch sensitive
poor wear characteristics
relatively expensive
