Hint: How do aluminum and steel differ in yield strength and ultimate tensile strength?
An example stress-strain curve is shown below with the critical regions called out:
Comparing aluminum vs. steel, these are the material properties which correspond to regions labeled on the stress-strain curve.
- Yield Strength: 76 MPa
- Ultimate Tensile Strength: 130 MPa
- Yield Strength: 350 MPa
- Ultimate Tensile Strength: 620 MPa
Values above are referenced this database of material properties, Make It From.
A good rule of thumb: Steel typically has 3x stiffness (Young’s Modulus) of aluminum. Depending on the exact alloy used and secondary processes of heat treatment or work hardening off steel, yield strength and tensile strength can vary anywhere from 295-2400 MPa and 200-2100 MPa respectively (MatWeb).
This hand-drawn stress-strain curve below is a good visual reference for how different grades of steel compare against aluminum.
The stress-strain curve shows a similar linear elastic region followed by yielding and plastic deformation. However, stainless steel typically has a greater resistance to plastic deformation compared to aluminum, and will exhibit a more gradual yielding and strain hardening behavior. This means that the curve will have a steeper slope in the plastic region, indicating that the material requires more stress to deform.
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