robbypowell's version from 2016-09-18 03:18


Question Answer
define: element that forms positive ions in solutions, loses electrons in solutionsmetal
a pure metal that can exist in more than 1 crystalline structure is referred to as ______Allotropic (e.g. Titanium)
example of an allotropic metalTitanium
List 2 pure metals used in dentistryGold (24K) and Platinum
Which is known for having a low corrosion rate in the mouth, noble or base metals?Noble
Gold, platinum, palladium, ruthenium, rhodium, iridium, and osmium are examples of ______ metalsNoble
Silver, copper, zinc, indium, gallium, nickle, cobalt, and chromium are examples of ______ metalsBase
Define: irreversible loss of electrons and metal mass → leads to loss of propertiesCorrosion
Define: buildup of chemical film on surface → dulls luster/brightnessTarnish
Tarnish on metals is usually made of _____ or ______Sulfide or Oxide
Define: Mixture of 2 or more metalsAlloy
Generally ______ are harder, stronger, and more corrosion resistance lower corrosion rates than pure metalsAlloys
(large/small) grain size leads to material that has higher tensile strength, more uniform propertiesSmall
faster cooling of alloy leads to ______ (larger/smaller) grainssmaller grains
2 examples of grain refiners (impurities that don’t melt at the same temp as the alloy and provide nucleation sites of the grain to form)Iridium and ruthenium
(Single/Multiple) phase alloys are homogenous and have lower corrosion ratesSingle phase
(Single/Multiple) phase alloys have higher corrosion ratesMultiple
(Single/Multiple) phase alloys have higher strength, higher corrosion rates, and lower elongationMultiple
T/F: Solid solution alloys are harder and stronger (tensile) by about 30-50% more than other alloysTrue
T/F: Solid solution alloys are more brittle and fracture more easily (tensile) by about 30-50% more than other alloysFalse (harder, stronger)
alloy type (on basis of phases) where second phase is included throughout the first phase and impede dislocationsDispersed Phase alloys (Ni-Cr, Au-Pt-Zn)
_____ percent: composition of alloys based on number of atomsAtomic Percent
_____ percent: composition of alloys based on mass; used commonly in industry and favors heavier elements → makes more noble elements appear more abundantWeight Percent
Type of alloy formed when an alloy is cast in one form and shaped into another form by rolling, drawing, or bendingWrought Alloys
T/F: if Wrought alloys are reheated, stress is released and grains recrystallize → properties go back to cast formTrue