material selection quiz 2

What is the starting material used to refine aluminum?

bauxite

Bauxite undergoes the ____ Process to get alumina

bayer

Alumina undergoes the _____-______ Process to get aluminum

hall-heroult

Aluminum has a ____ or _____ yield strength than most structural materials

similar or lower

Aluminum generally has ______ fracture toughness than most structural materials

lower

Aluminum generally has a _____ elastic modulus than most structural materials

lower

Aluminum has a significantly ____ density than most structural materials and thus _____ specific strength (strength-to-weight ratio)

lower, high

How much of all aluminum ever produced still in use today?

75%

What two elements combine to make steel?

Fe and C

Specialty stainless steels can only have ~__-__% Fe content

60-70

To produce elemental iron, you need iron in the form of ______, carbon in the form of ____, and calcium in the form of ____.

iron ore, coke, lime

When making iron in a blast furnace, you need ____ to melt the ore and ___ to remove impurities.

fuel, flux

Blast furnace reaction:
Fe_O_+3CO → __Fe + 3CO2

23, 2

What are the impurities that float to the top of molten iron in a blast furnace?

slag

What does a blast furnace produce?

pig iron

Why can’t you use pig iron?

4%C, too brittle

To refine pig iron and make steel, you add ___ in a basic ____ furnace. What does the carbon content reduce to?

oxygen, 0.04%

Compared to a BOF, an electric arc furnace can only use _____ _____ or ________.

scrap steel, direct reduced iron

Once steel is made, it undergoes a secondary refining to promote _____ and ____ homogenization and lower ____ levels.

temperature, composition, impurity

Austenitic steels (___ series) are non-magnetic, have excelllent corrosion resistance, and great formability. What is a common application?

300, kitchen appliances

ferritic steels (___ series) are magnetic, good corrosion resistance in mild environments, and are cost-effective. What are two common applications?

400, exhaust systems, architectural trim

martensitic steels are magnetic, have good wear resistance, and are easily hardenable. what is a common application?

cutting tools

What type of steel is most commonly used in aerospace parts?

precipitation hardened

Steel has a _____ elastic modulus than most structural metals

higher

During a uniaxial tensile test, the specimen is elongated in one direction at a fixed _____ rate

displacement

In a stress-strain curve, the slope in the elastic region represents a materials ___ ____.

elastic modulus

The ultimate tensile strength occurs at the onset of ____, or non-uniform deformation.

necking

What property quantitatively describes the energy required for fracture or, alternatively, the amount of energy that can be absorbed before fracture

fracture toughness