Chapter 76 - Metallic instruments and implants Flashcards
How may the types of stainless steel used for instruments be classified?
By their microstructure, magnetic attraction, corrosion resistance, and hardness.
What is the microstructure of 400 series stainless steel described as?
Martensitic.
Stainless steel can be classified according to 4 things name them
- Microstratucture
- Magnetic attraction
- Corrosion resistance
- Hardness
What percentage of chromium do martensitic compositions typically contain?
12% to 18%.
term martensitic describes
the type of microstructure
associated with 400 series stainless steel
The 400 series nomenclature refers
to various well-defined alloys, which include compositional trends
related to ________ and ________ content
The 400 series nomenclature refers
to various well-defined alloys, which include compositional trends
related to carbon and chromium content
Name the A, B , C range of carbon for each stainless steel
A, B, or C define an increasing carbon range for a given
alloy (420C > 420B > 420A)
how does the chromium range increase in stainless steel?
chromium range increases
as the three-digit 4XX number increases (440 > 431 > 420).
For the alloy the hardness typically increases or decreases with tempering temperature increases?
For a given alloy, the
hardness typically decreases as the tempering temperature
increases.
Martensitic alloys are very fragile or very hard and resistant?
Martensitic alloys are very hard and resistant to wear,
which makes them ideal for cutting instruments (such as drills,
taps, countersinks, reamers, chisels, and bone-cutting forceps)
and for use in noncutting tools (such as screwdrivers and
wrenches).
Precipitation hardenable (PH) stainless steels contains what?
Precipitation hardenable (PH)
stainless steels contain substantial amounts of chromium, nickel, and copper, plus controlled levels of secondary elements
final hardness is inversely related to the
Various age-hardened techniques (e.g., H900 and H950) are used,
and the final hardness is** inversely** related to the age-hardening
temperature
Precipitation hardenable (PH) instruments are used for what?
non-cutting instruments that require moderate hardness level
Precipitation hardenable (PH) instruments have high or low carbon content
PH has low carbon content
The term austenitic describes the type of microstructure associated
with ___________stainless steel
The term austenitic describes the type of microstructure associated
with 300 series stainless steel
Name two proprietis of austenitic microstructures
has magnetic
excellent corrosion resisten
Name the % of composition in austenitic
The austenitic compositions3
usually contain 16% to 18% chromium and 8% to 10%
nickel.
Name application/instruments using austenitic
drill guides, clamps, hollow sleeves, springs,
and washers.
What does the suffix letter in the nomenclature of martensitic alloys of the 400 series indicate?
The increasing carbon range for a given alloy.
Which heat treatment temperature range is used to harden martensitic alloys?
930°C to 1150°C.
What is a commonly used PH-grade alloy for instruments?
A) 17-4PH.
B) 13-8Mo.
C) 9-12% Nickel.
D) 21-6-9.
A) 17-4PH.
Which microstructure is associated with 300 series stainless steel?
A) Martensitic.
B) Austenitic.
C) Ferritic.
D) Duplex.
B) Austenitic.
What element is added to 316 and 316L austenitic stainless steels to alter its magnetic properties?
A) Molybdenum.
B) Cobalt.
C) Titanium.
D) Vanadium.
A) Molybdenum.
What is Grade 1100 aluminum primarily used for?
A) Cutting instruments.
B) Bone plate or rod templates.
C) High-strength applications.
D) Color-coded instrument systems.
B) Bone plate or rod templates.