Properties Flashcards
What do the digits of the SAE/AISI steel designate?
XXXX
First two indicate the material in the steel, second two digits indicate carbon content (10 = 0.1%)
1010 Steel = low carbon steel with .1% carbon content
What is 4130 steel composition?
Chrome-Moly steel with 1% Chrome and 0.3% Carbon
composition 5130 steel?
1% Chromium steel with 0.3% carbon
Define Wallner Lines
Failure analysis tool, especially in amorphous/polycrystalline materials like glass. Wallner lines are rib shaped marks which indicate crack propagation direction. the wallner line is perpendicular to the crack propagation direction.
What element will increase tensile strength of steel?
Carbon content
What type of indenter does the Brinell Hardness test use, and what is the abbreviation?
10mm sphere of steel or tungsten, BHN
What type of indenter does the Vickers Hardness test use, and what is the abbreviation?
symmetrical Diamond pyramid, VHN
What type of indenter does the Knoop microhardness test use, and what is the abbreviation?
elongated diamond pyramid, KHN
What type of indenter does the Rockwell Hardness test use (for each grade), and what is the abbreviation?
A, C, D - Diamond Cone
B, F, G - 1.6 mm steel sphere
E - 3.2 mm steel sphere
Abbreviation: R (subscript)
Define Hardness
a measure of resistance to permanent plastic deformation
What affect on material properties does grain size have?
Elastic modulus
Strength
Hardness
Ductility
Smaller grain size = higher strength, higher hardness.
DOES NOT DECREASE DUCTILITY or Elastic Modulus
What does the Hall Petch Equation describe?
That yield strength is inversely proportional to the square root of the grain size.
Smaller grains = stronger material
What factors can affect the Young’s modulus (elastic modulus) of a given material?
Trick Question. Young’s modulus is a material property and cannot be altered by processing.
How to calculate density of composite given densities of components? 80% composite 1 and 20% composite 2
Assume 100g composite, then divide 80g by density 1 and 20g/density 2. Add 2 volumes together (volume of total sample).
Then 100g / volume = density of composite
What mechanical properties does 65-45-12 Ductile Iron have?
> = 65 ksi tensile
= 45 ksi yield
12% elongation