Stainless Steel & Wrought Alloys Flashcards
what is a wrought alloy?
an alloythat has been beaten out/shaped by hammering (cold working)
what is a wrought alloy?
an annoy that has been beaten out/shaped by hammering (cold working)
what are examples of wrought alloys used in dentistry?
- wires (orthodontic)
- partial denture clasps
what are examples of wrought alloys used in dentistry?
- wires (orthodontic)
- partial denture clasps
what are examples of wrought alloys used in dentistry?
- wires (orthodontic)
- partial denture clasps
what is the composition of steel?
Iron (98%)
Carbon (1.5%)
Chromium (0.5%) - improve tarnish resistance
what does allotropic mean?
the existence of an element in TWO or more forms in the same physical state. The arrangement of their atoms are different
What makes stainless steel, stainless? and what property does this add?
if chromium is 12% or more
Corrosion resistance due to the chromium oxide layer
what are the 2 types of stainless steel?
- Martensitic
- Austenitic
what is martensitic stainless steel vs austenitic stainless steel?
Martensitic - alloy which has more chromium and ordinality no nickel in it. Less corrosion resistant
Austenitic SS - alloy which has exceptional corrosion resistance and impressive mechanical properties
what are uses of austenitic stainless steel?
- Dental equipment & instruments (NOT cutting edge equipments). Corrosion resistant
- wires (orthotics etc)
- sheet forms for denture bases
what is the components of stainless steel wires?
74% iron
18% chromium
8% nickel
0.1% carbon
what is cold working and what does it do?
work done on metal/alloy at LOW TEMP
causes permanent change in their crystalline structure reducing the ability of further movement of crystals within the metal making it MORE resistant to deformation.
what is the definition of springiness in a material?
ability to undergo large deflections without permanent deformations whilst returning to its original shape
