120103h Flashcards
Which metal is lighter than Al
a) magnesium
b) copper
c) steel
d) manganese
a) magnesium
Al is a reactive metal.
What is meant by reactive?
A reactive metal is one that readily reacts with other elements.
Al reacts very quickly with O2 to form Al oxides
Al has a refractory oxide.
What is a refractory oxide?
Refactory oxide means that the oxide is difficult to melt, reduce or work.
The oxide of Al melts at a much higher temp than the parent metal.
How does the electrical and thermal conductivity of Al compare with that of mild steel?
The electrical and thermal conductivity of Al is aprox 4X that of mild steel
What are the aprox melting points of the following materials
a) Al
b) Al oxide
a) 660°C / 1220°F
b) 2037°C / 3700°F
Under the same conditions a section of Al would deflect ______ times as much as a similar section of mild steel
Under the same load, a section of Al would deflect 3X as much as a similar section of steel
What process may be used to enhance the Al oxide film for increased corrosion resistance
Anodizing increases the thickness of the oxide layer
The coefficient of linear expansion of Al is aprox:
a) equal to that of steel
b) half that of steel
c) twice that of steel
d) four times that of steel
2X that of steel
In the Al Association wrought iron Al alloy numbering system, the first digit indicates
a) the alloy group
b) the Al alloy
c) the Al purity over 99%
d) modifications to the original alloy
a) the alloy group
In the Al Association wrought iron Al alloy numbering system, the second digit indicates
a) the alloy group
b) the Al alloy
c) the Al purity over 99%
d) modifications to the original alloy
d) modifications to the original alloy
What is the purity of a 1050 Al alloy
1050 Al alloys are 99.5% pure
In the Al Association wrought iron Al alloy numbering system for 1XXX series the last 2 digits indicate :
a) the alloy group
b) the Al alloy
c) the Al purity over 99%
d) modifications to the original alloy
c) the Al purity over 99%
What does the number 43 indicate in the filler wire designation ER4043
a) the carbon content
b) the alloys added
c) the minimum purity
d) the % of Mg added
b) the alloys added
Which Al alloy contains substantial amounts of Mg
a) AA 1030
b) AA 2014
c) AA 5356
d) AA 4043
c) AA 5356
What does the 4th digit indicate for Al alloy casting
a) min Al content
b) product form
c) modifications of the original alloy
d) type of heat treatment
b) product form
The Al wrought alloysin the groups 1XXX, 3XXX, & 5XXX series are:
a) heat treatable
b) non heat treatable
c) hardenable
d) temperable
b) non heat treatable
The Al wrought alloys in the groups 2XXX, 6XXX, & 7XXX series are:
a) heat treatable
b) non heat treatable
c) unworkable
d) unused
a) heat treatable
How can the mechanical properties of heat treated Al alloys be restored after welding
The properties may be restored by heat treating again
Heating an Al alloy to a temperature below its melting point for a specified period of time and then quenching from this temperature is called:
a) tempering
b) hardening
c) aging
d) solution heat treating
d) solution heat treating
Non heat treatable wrought alloys are designated with several levels of mechanical properties. Which does not indicate a mechanical property designation?
a) H1 ( work hardened only)
b) A ( anodized)
c) O (fully annealed)
d) F (as fabricated
b) A ( anodized)
The mechanical properties of ____ -____ ____ Al alloys are improved by cold working and drawing
The mechanical properties of non-heat treatable Al alloys are improved by cold working and drawing
Which 2 filler metals may be used to weld most weldable Al alloys
a) ER1100 & ER3003
b) ER4043 & ER5356
c)ER5083 & ER 5454
d) ER6061 & ER 6351
b) ER4043 & ER5356
When welding a 6061-T6 alloy, which filler metal alloy is generally the best choice
ER4043
What is the primary consideration when selecting filler metals when using GMAW on Al?
a) the amperage and voltage settings
b) matching base metal and filler metal chemistry and mechanical properties
c) the temper designation of the base metal
d) the type of joint to be welded
b) matching base metal and filler metal chemistry and mechanical properties
Which is true of an ER5356 Al alloy?
a) there have been no modifications
b) It is 99.56% pure Al
c) It is a heat treatable Al
d) Mg is the major alloying element
d) Mg is the major alloying element
What type of alloy is an ER4043 filler wire
a) Al & silicon
b) Al & Mg
c) Al & manganese
d) silicon & manganese
a) Al & silicon
Where are the drive rolls located on a pull type drive system?
a) in the gun itself close to the contact tip
b) in the main wire feed unit
c) on the drum some distance behind the wire feeder
d) the same place as on a push type system
a) in the gun itself close to the contact tip
A pull type welding gun is designed to be used with:
a) hard wires
b) soft wires
c) solid core wires
d) tubular wires
b) solid core wires
What type of wire drive system allows greater machine to work distances
a) push system
b) push-pull system
c) 2 drive roll system
d) 4 drive roll system
b) push-pull system
Push - pull guns are an advantage when:
a) soft wires are taken through short liners
b) hard wires are taken through short lines
c) soft wires are taken through long liners
d) hard wires are taken through long liners
c) soft wires are taken through long liners
What type of metal transfer occurs with Al GMAW and 100% Ar shielding?
a) short circuiting
b) globular
c) dip transfer
d) spray
d) spray
What is the most likely cause of a porous, dirty weld bead?
a) drag technique
b) globular
c) dip transfer
d) spray transfer mode
a) drag technique
What is the most likely cause of the wire melting back on the contact tip?
a) wire feed speed to high
b) wire feed speed to slow
c) welding with a forehand technique
d) diameter of the wire matches the drive rolls
b) wire feed speed to slow