Intro Flashcards
Test for hardness and softness
Knoop
Test for brittleness
Vickers
Greatest stress to which a material can be subjected such as it will return to its original dimensions when forces are released
Elastic limit
Measure of the stress/load allowed before permanent deformation occurs
Yield strength
Value at the point where a material subjected to stress will fracture
Ultimate strength
Indicates the energy required to deform a material permanently
Resilience
Total amount of energy necessary to fracture a material
Toughness
Ability of the material to withstand permanent deformation under a tensile load without rupture
Ductility
Ability of a material to withstand permanent deformation without rupture under compression
Malleability
Basic composition of reversible hydrocolloid providing the dispersed phase of the sol and the continuous fibril structure of the gel
Agar
Accelerator for the gypsum; counteracts the inhibiting effect of borax and agar on the setting gypsum
Potassium sulfate
Increase the strength and viscosity of the reversible compound’s sol; retards the setting time of the gypsum
Borax
Increase the strength, viscosity and rigidity
Fillers
Increase viscosity
Thickeners
Principal ingredient in reversible hydrocolloids which controls the flow properties of the sol and the physical properties of the gel
Water
