4.2 Performance of Metals Flashcards
What are the mechanical properties for metals?
- Hardness
- Toughness
- Malleability
- Elasticity
- Tensile strength
Are alloys or pure metals usually stronger? Explain why
Alloys are usually stronger, asthey have different sized atoms which mean they are less able to slide over one anothermaking the metal harder
Which are the hardest metals?
Tungsten and titanium
Why is mild steel used in the manufacture of car bonnets?
- Mild steel is strong and durable to withstand stresses and impacts, such as minor collisions and road debris
- Mild steel is relatively easy to form and shape, allowing manufacturers to create complex curves and contours
Which metals are most malleable?
Gold, silver, aluminium and copper
Which metals are most ductile?
Gold, silver, copper and aluminium
In what ways can the stength of metals be measured?
- Compressive strength
- Tensile strength
- Bending strength
- Torsional strength
- Shear strength
What is compressive strength?
the ability to withstand being crushed or shortened by pushing forces
What is tensile strength?
It is the ability to resist stretching or pulling forces
What is bending strength?
It is the ability to resist forces that may bend the material
What is torsional strength?
It is the ability to withstand twisting forces from applied torque or torsion
What is shear strength?
The ability to resist sliding forces on a parallel plane
What are two metals that have relatively low densities?
Aluminium and titanium
What are the physical properties for metals?
- Density
- Melting points
- Thermal conductivity
- Electrical conductivity
- Resistance to corrosion
- Ability to take coatings and finishes
- Ability to be alloyed and joined with heat processes
List three different applications of copper where thermal conductivity is important
- Cookware, as it is essential that heat is distributed evenly across the cooking surface, preventing hot spots and ensuring uniform cooking
- Electrical wires, as conducts heat away from wires, preventing overheating and ensuring safety
- Plumbing Systems, as it allows hot water to reach taps and fixtures quickly while minimizing energy losses in hot water distribution
Which metal has the highest melting point?
Tungsten at 3422°C
Which metals have very low melting points?
- Mercury (at -38.9°C)
- Pewter (at 170–230 °C)
- Tin (at 232°C)
- Lead (at 327.5°C)
Which metal has the best electrucal conductivity?
Silver (Copper also has good conductivity and is more cost effective)
What makes makes titanium ideal for use in hip and knee replacements?
- It is highly resistant to corrosion, reducing the risk of adverse reactions within the body
- It has a strong and durable structure, able to withstand the mechanical stresses associated with joint replacements
- Despite its strength, titanium is relatively lightweight, contributing to patient comfort and mobility
Why is Aluminium suitable for a drinks can?
- It’s malleable which allows the can to be deep drawn into shape
- It’s lightweight- easier to transport, adds little to the product weight
- It’s a food safe material
- It’s non-ferrous so won’t rust on contact with the liquid in the can
- Easy to recycle and use for other products (low melting point)
What makes brass suitable for use in a trumpet?
- It is malleable, easy to shape and machine, allowing for intricate designs that contribute to the trumpet’s unique sound and structure
- Brass has good corrosion resistance, as it is exposed to moisture from breath
