Ferrous & Non-Ferrous Material Properties Flashcards

What is the Brinell Hardness Number (BHN) test most suitable for measuring?

Answer: Large castings and forgings with coarse grain structures

The Brinell test uses a large steel or carbide ball indenter and is best suited for large, coarse-grained materials like castings and forgings.

Which non-ferrous metal has the highest electrical conductivity among commonly used engineering metals?

Answer: Silver

Silver has the highest electrical conductivity of all metals, though copper is more commonly used due to cost.

When machining copper, the main challenge is:

Answer: High work hardening rate and tendency to form built-up edge

Copper's high ductility causes it to smear and form built-up edge on cutting tools, requiring sharp tools and appropriate cutting fluids.

D2 tool steel is classified as a:

Answer: High-carbon, high-chromium cold work tool steel

D2 is a high-carbon (1.5% C), high-chromium (11-13% Cr) cold work tool steel known for excellent wear resistance.

Which stainless steel family is generally non-magnetic and cannot be hardened by heat treatment?

Answer: Austenitic stainless steel

Austenitic stainless steels (300 series) retain their FCC crystal structure at room temperature, making them non-magnetic and hardenable only by cold working.

Which material property is directly measured by a Charpy or Izod impact test?

Answer: Toughness (impact energy absorbed)

Charpy and Izod tests measure the energy absorbed by a notched specimen when struck by a pendulum, quantifying toughness.

Magnesium alloys are attractive for aerospace and automotive parts primarily because:

Answer: They are the lightest structural metal in common use

Magnesium has a density of about 1.74 g/cm³, making it the lightest structural metal, which is critical for weight-sensitive applications.