Part 10: metals

Question 1

Metals possess allotropy. Define allotropy.

Answer 1

The same element have two or more different structures

Question 2

Stainless steel gets its corrosion resistant properties from which substitutional element?

Answer 2

Chromium

Question 3

What is the difference between cast and wrought alloys?

Answer 3

Wrought alloys can be plastically deformed into shape with forming techniques due to their high ductility. Cast alloys are too brittle to be plastically deformed and must be melted and poured into a mold.

Question 4

What are four methods of forming for metal fabrication?

Answer 4

1. Forging
2. Rolling
3. Extrusion
4. Drawing

Question 5

What are four methods of casting for metal fabrication?

Answer 5

1. Die casting
2. Continuous casting
3. Sand casting
4. Investment casting

Question 6

What are two methods of 3D printing metal objects?

Answer 6

1. Direct energy deposition
2. Powder bed fusion

Question 7

Name some properties of copper

Answer 7

• Electrical and thermal conductivity
• Corrosion resistance
• Ductile

Question 8

Name some properties of aluminum

Answer 8

• Electrical and thermal conductivity
• Corrosion resistance
• Ductile
• Low melting temperature
• Low density

Question 9

Name some properties of magnesium

Answer 9

• Low melting temperature
• Low density
• Low young’s modulus

Question 10

Name some properties of titanium

Answer 10

• Low density
• High melting point
• High strength
• High ductility
• Biocompatibility

Question 11

What is the property of refractory metals?

Answer 11

Very high melting temperature