Mechanical Properties of Engineering Materials
We use various materials in engineering. The selection of materials for an application is based on the Mechanical properties of the particular material.
The materials posses various properties such as
- Hot Hardness
Strength is the maximum force required to fracture a unit cross sectional area of the given material in tension.
Tensile strength = Maximum force used to fracture in N / Original cross sectional area in mm²
The strength of 0.4% Carbon steel is approximately 350 N/ mm². The strength can be improved by alloying and heat treatment.
Tensile strength calculation
Max force used = 40000 N
Diameter of the rod 10 mm
Cross sectional area = (π / 4 ) d²
= ( 3.14 / 4 ) x 10 x 10
= 78.55 mm²
Tensile strength = 40000 N / 78.55 mm²
= 510 N/ mm²
The ability of the material to resist scratch, wear and indentation by harder substances.
The most common methods of hardness testing are Rockwell Hardness Test (HRC) and Brinell Hardness Test (BHN). The Hardness value of Center punch is 56 HRC.
The ability of the material to be broken into pieces when hammering load is applied.The more the Harder the Material the more brittle the material becomes.
The toughness is the ability of a material to absorb energy and plastically deform without fracturing
Toughness testing: Charpy or Izod test are the standard test for toughness. Toughness is measured in units of joules – J
In the testing the piece is broken by striking a hammer against it. The energy absorbed in Joules while breaking is the toughness value.
The ability of the material to deform under a compression load. This allows the material to be changed into any desired shape using compression load.
The ability of the material to be drawn into thin wires under tensile load.
Hot hardness: The ability of a material to retain hardness and wear resistance at high temperatures
Hot hardness Testing: Hot hardness testing is the measurement of material hardness while at high temperature.
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