MMET 207 EXAM III QUESTIONS AND ANSWERS
1000 Al - Answers :commercially pure aluminum (99% minimum)
2000 Al - Answers :copper
3000 Al - Answers :manganese
4000 Al - Answers :silicon
5000 Al - Answers :magnesium
6000 Al - Answers :magnesium and silicon
7000 Al - Answers :zinc
7000-F - Answers :zinc; as fabricated
4000-W - Answers :silicon; solution heat treated
3000-O - Answers :manganese; annealed
5000-H12 - Answers :magnesium; 1/4 strain hardened
3000-H18 - Answers :manganese; full strain harden
What Aluminum series are heat treatable? - Answers :2000, 6000, 7000
What aluminum series are not heat treatable? - Answers :1000, 3000, 4000, 5000
2000-T3 - Answers :copper; furnace solution heated, quenched and COLD WORKED
6000-T4 - Answers :magnesium and silicon; furnace solution heat treated, quenched
and NATURALLY AGED
7000-T6 - Answers :zinc; furnace solution heat treated, quenched and FURNACE
AGED
What are the physical properties of aluminum compared to other metals? - Answers
:lighter than all other engineering metals, high thermal and electrical conductivity, good
corrosion resistance in atmospheric environment
Aluminum has how much of the conductivity of pure copper? - Answers :60%
, Which has a higher conductivity per unit mass, aluminum or copper? - Answers
:aluminum
How is precipitation hardening done? - Answers :temperature raised to about 800F,
water quenched and then aged
What is the stress relieving process for aluminums? - Answers :can be done on all
alloys to prevent stress corrosion cracking
What is the highest temperature heat treatment for aluminums? - Answers
:precipitation/solution hardening
What is the longest heat treatment for aluminums? - Answers :aging, which is also done
at the lowest temperature
What is the difference between anodizing and hard coating? - Answers :anodizing is a
thinner layer and can be colored, hard coating is thicker and done for corrosion and
wear resistance only
What should you keep in mind when anodizing? - Answers :corners are hard to anodize,
so rounded edges are better for this
How is anodizing done? - Answers :it is set up in a corrosive cell to help aluminum
oxides form
What elements can cause problems in anodizing? - Answers :copper and silicon
Which aluminum alloys are the most susceptible to stress corrosion cracking? -
Answers :2000 and 7000
Which aluminum alloys are least likely to stress corrode crack? - Answers :1000, 3000,
6000
Which aluminum alloy has the best resistance to stress corrosion cracking? - Answers
:6061
In what environments is pitting found in aluminum? - Answers :high salt, seawater and
water in general
What affect does detergent have on aluminum? - Answers :it leads to heavy corrosion
attack
Which aluminum alloys machine best? - Answers :age-hardened
What is the stiffness of aluminum compared to steel? - Answers :1/3 stiffness of steel
1000 Al - Answers :commercially pure aluminum (99% minimum)
2000 Al - Answers :copper
3000 Al - Answers :manganese
4000 Al - Answers :silicon
5000 Al - Answers :magnesium
6000 Al - Answers :magnesium and silicon
7000 Al - Answers :zinc
7000-F - Answers :zinc; as fabricated
4000-W - Answers :silicon; solution heat treated
3000-O - Answers :manganese; annealed
5000-H12 - Answers :magnesium; 1/4 strain hardened
3000-H18 - Answers :manganese; full strain harden
What Aluminum series are heat treatable? - Answers :2000, 6000, 7000
What aluminum series are not heat treatable? - Answers :1000, 3000, 4000, 5000
2000-T3 - Answers :copper; furnace solution heated, quenched and COLD WORKED
6000-T4 - Answers :magnesium and silicon; furnace solution heat treated, quenched
and NATURALLY AGED
7000-T6 - Answers :zinc; furnace solution heat treated, quenched and FURNACE
AGED
What are the physical properties of aluminum compared to other metals? - Answers
:lighter than all other engineering metals, high thermal and electrical conductivity, good
corrosion resistance in atmospheric environment
Aluminum has how much of the conductivity of pure copper? - Answers :60%
, Which has a higher conductivity per unit mass, aluminum or copper? - Answers
:aluminum
How is precipitation hardening done? - Answers :temperature raised to about 800F,
water quenched and then aged
What is the stress relieving process for aluminums? - Answers :can be done on all
alloys to prevent stress corrosion cracking
What is the highest temperature heat treatment for aluminums? - Answers
:precipitation/solution hardening
What is the longest heat treatment for aluminums? - Answers :aging, which is also done
at the lowest temperature
What is the difference between anodizing and hard coating? - Answers :anodizing is a
thinner layer and can be colored, hard coating is thicker and done for corrosion and
wear resistance only
What should you keep in mind when anodizing? - Answers :corners are hard to anodize,
so rounded edges are better for this
How is anodizing done? - Answers :it is set up in a corrosive cell to help aluminum
oxides form
What elements can cause problems in anodizing? - Answers :copper and silicon
Which aluminum alloys are the most susceptible to stress corrosion cracking? -
Answers :2000 and 7000
Which aluminum alloys are least likely to stress corrode crack? - Answers :1000, 3000,
6000
Which aluminum alloy has the best resistance to stress corrosion cracking? - Answers
:6061
In what environments is pitting found in aluminum? - Answers :high salt, seawater and
water in general
What affect does detergent have on aluminum? - Answers :it leads to heavy corrosion
attack
Which aluminum alloys machine best? - Answers :age-hardened
What is the stiffness of aluminum compared to steel? - Answers :1/3 stiffness of steel
