Arc Furnace Melting and Sand Casting of Aluminum and Copper James Bonnell James O’Brien Engr 45 Dec 8, 2004
Arc Furnace Melting and Sand Casting of Aluminum and
CopperJames BonnellJames O’Brien
Engr 45Dec 8, 2004
Arc Furnace Typical Uses
• Metal Recycling• Used to reclaim iron, nickel and cobalt alloy• Scrap is generally 100% of the charge• With computer control is used to separate
various mixed scrap to specific compositions
Arc Furnace
Benefits:• Cost per ton of final product is less
(taking into account all expendables)
• Can melt almost any type of metallic scrap• Good for smaller production runs requiring
less capacity.
Source: http://tristate.apogee.net/et/
Power Consumption
Energy Required to Produce One Ton of Liquid Steel
0
2
4
6
8
10
12
14
16
18
20
Arc Furnace Oxygen FurnaceProcess
Mill
ion
Btu
Source: http://tristate.apogee.net/et/
Cost Per Ton of SteelMaterial Cost per Ton of Produced
Steel
0
20
40
60
80
100
120
140
Arc Furnace Blast FurnaceProcess
Dol
lars
per
Ton
Source: http://tristate.apogee.net/et/
Current Carrying Capacity
Source: www.foundrytraders.com
Nominal Diameter Electrode Type
mm inch Regular Power High Power Ultra High Power
75 3 1,000 ~ 1,400 100 4 1,500 ~ 2,400 150 6 3,000 ~ 4,500 200 8 5,000 ~ 6,900 5,400 ~ 9,000 250 10 7,000 ~ 10,000 8,000 ~ 12,000 300 12 10,000 ~ 13,000 13,000 ~ 17,400 18,000 ~ 22,000
350 14 13,500 ~ 18,000 17,400 ~ 24,000 20,000 ~ 30,000
400 16 18,000 ~ 23,500 21,000 ~ 31,000 25,000 ~ 40,000
450 18 22,000 ~ 27,000 25,000 ~ 40,000 32,000 ~ 45,000
500 20 25,000 ~ 32,000 30,000 ~ 48,000 38,000 ~ 55,000
Modified Arc Lamp
• Moved the bottom electrode to be parallel with the top electrode
• Added:• Platform• Crucible
Sand Casting Suitability
Advantages:Least Expensive Casting
ProcessCastings can be up to Several
TonsLess Expensive than
Machining Shapes from Bar Stock
Can Cast Intricate ShapesCan be Used with Most
Pourable Metals and Alloys
Disadvantages:Can Only Cast Basic Part Shape
Castings Require Secondary Machining
Rough Surface Finish
www.casting-source.com
Casting Sand Types
• Basic casting sand consists of bentonite clay and sand (usually 120 grit)
• Chromite sand: a high quality refractory molding sand,with high chilling effect and stability
• Zircon sand: particularly suitable for higher melting point alloys
Source: http://www.foundrytraders.com
Shrinkage Consideration
Shrinkage Rate for Small Castings
Iron - 1/8" per foot
Steel - 1/4" per foot
Aluminum - 5/32" per foot
Brass - 3/16" per foot
www.casting-source.com
Disappointing Results
• Insufficient input heat to maintain molten state
• Worked to melt small samples
• Crucible broke from thermal shock when the sample melted