DENT1128: Metals & Alloys

What is a metal?

• a) any chemical element that loses one or more valence electrons to form a positive ion

• b) any chemical element that gains one or more valence electrons to form a negative ion

• c) any chemical element that gains two or more valence electrons to form a positive ion

• d) any chemical element that loses two or more valence electrons to form a positive ion in a chemical reaction

Metal crystals are called "grains"

• a) True

• b) False

Alloys have a melting point; Pure metals have a melting range.

• a) Both statements are true

• b) Both statements are false

• c) First statement is true; second statement is false

• d) First statement is false; second statement is true

Pure metals have specific characteristics; Alloys have combined characteristics.

• a) Both statements are true

• b) Both statements are false

• c) First statement is true; second statement is false

• d) First statement is false; second statement is true

Pure metals have a fixed melting and freezing point.

• a) True

• b) False

Liquidus point/temperature is the point where the alloy starts to melt.

• a) True

• b) False

Solidus point/temperature is the temperature at which the alloy is completely melted.

• a) True

• b) False

Heating metals to a specific temperature below red hot can relieve stresses in metal and increase their hardness...this type of heat treatment is called?

• a) Annealing

• b) Tempering

• c) Stress relieving

• d) Quenching

• e) Hardening

What is the opposite of tempering?

• a) Annealing

• b) Hardening

• c) Quenching

• d) Stress Relieving

All noble metals are precious, but not all precious metals are noble...

• a) True

• b) False