Mechanical Engineering - Engineering Materials - Discussion

The correct answer is Copper.

Copper is known for its high ductility, with a ductility percentage of around 50-60%. This means that copper can be stretched or drawn out to a significant extent without breaking.

Here's a rough ranking of the materials you listed by their ductility:

1. Copper (50-60%)
2. Aluminium (20-30%)
3. Mild steel (15-25%)
4. Nickel (10-20%)

Note that ductility can vary depending on the specific alloy, processing history, and testing conditions.

However, in general, copper is considered one of the most ductile metals.

Mild steel has moderate ductility, while nickel has relatively low ductility compared to the other options. Aluminium has intermediate ductility, but it's still lower than copper.

Mild steel having more ductile behavioural phenomenal than the aluminium and reason is that;

Mild steel shows BCC crystal structure and Aluminium shows FCC.

And BCC is more ductile than FCC structure and one more best reason for why aluminium shows a less ductile than mild steel is. FCC crystal structure cannot show ductile to the Brittle transition temperature and only BCC can shows.

This is the main reason.

Given materials are Ms, Al, Cu, and Ni. There didn't mention any condition like whether it is proportional limit, elastic deformation zone, plastic deformation zone or ultimate zone.

Then according to material properties are valid under the proportional limit.

So maximum value of young's modulus its gives high ductility.

E (steel) =200Gpa.

E (copper) =117 Gpa.

E (Al) = 69 Gpa.

E (Nickel) =170 Gpa.

I guess Fe is having BCC structure where Al is of FCC. FCC structure materials are more ductile than the BCC. Adding carbon in Fe will increase its hardness. So according to these facts Al should be more ductile than MS.

But in practical(Tensile test) MS will have more elongation than Al for the same dimensional specimen. This is somewhat confusing.

Ductility is the ability of a material to deform plastically under Tensile Load.

Malleability is the ability of a material to deform plastically under Compressive Load.

Aluminium is more malleable than Mild steel, although Mild Steel is more ductile than Aluminium.

Mild steel is more ductile metal because undergo large permanent strain before failure. And large reduction in area before fracture.

If strain post elastic strain is greater than 5%, it is called ductile material. Also mild steel is more elastic than rubber.

Ductility of metals depends on the strength of metallic bonding among atoms.
(attraction between sea electrons/that depend on the number of valence electrons and atomic kernels).

So the answer is Al.

The ductility of steel varies depending on the alloying constituents. Increasing levels of carbon decreased ductility.

The most ductile metal is platinum and the most malleable metal is gold.

Mild steel is consider as plain carbon steel. That is low alloy steel. Have very less carbon.

It will show negative hardness in rock well. So it will more ductile.

I believe there is a constant yield value for the above mentioned elements, on consideration its mild steel. It can withstand more tensile force before necking.