Actually i want to compare the process parameter of casting and powder

metalluargy,

The metal cold-cast process is faster and much less expensive when compared with foundry casting of molten metal (lost wax process).Different metal powders such as bronze, brass, aluminum, nickel-silver and copper can be used depending on the effect desired.

What is cold-cast process, how this process is good then the foundry casting.

Refer this ppt

if you're actually trying to melt aluminum powder, you might encounter problems. this is because aluminum rapidly oxidizes in the powder state, since surface to volume ratio is high in powders

I guess you might need vacuum to achieve your goal

How its possible to achieve the vacuum. When i try to make a arrangement to create the vacuum the project cost is very high so give some another idea.

I don't know man. But if you have aluminum powder, you may use powder metallurgy methods such as CIP or HIP (cold and hot isostatic press). I have no other ideas...

Better to go for some protective atmosphere if you feel vacuum is difficult, But oxidation will still be there, bottom pouring might be a solution....

We melt aluminium powder after cold pressing without any oil utilizing electron beam melting in vacuum.

3D Printing.

I am not sure I understand the question. There are significant differences between casting and powder metallurgy. Why use powders for casting? You can take a piece of Al and cast it directly, by induction or by direct heating in a furnace. If it's a special Al alloy and you only have powders, compact these powders, make a solid button and melt that. In any case at the stage of pouring you will get a sleeve made of Al2O3 and this sleeve will protect your sample from further oxidation. Unless of course you perform the whole process in vacuum.

Casting of aluminium powder is possible however is unpractical. Prompt oxidization of aluminium would occurr unless some protection is provided. If there is no need to closely control the properties of material is however possible to cast without an inert gas shield. I still would use proper aluminium ingots than powder in any cases since they are also cheaper.

For a high quality aluminum casting, the melt should be free from oxides. When you use aluminum powder, your melt quality will be very low, making it impossible to get a quality casting regardless of how you melt it.

Aluminium alloys can be cast using Cold Chamber Die casting process. The typical aluminium products that are made using die casing are rotors used in small electric motors ( FHP motors- Fractional horse power motors) used in refrigerators, washing machines, etc, and the door handles for refrigerators and racks.

Casting is a simple, inexpensive and versatile way of forming aluminum into a wide array of products. Such items as power transmissions and car engines and the cap atop the Washington Monument were all produced through the aluminum casting process. Most castings, especially large aluminum products, are usually made in sand molds.

Take-Away Facts

Casting must include a part-removal design

Casting molds must be designed to accommodate each stage of the process. For part removal, a slight taper (known as draft) must be used on surfaces perpendicular to the parting line so the pattern can be removed from the mold.

Casting parts with cavities

To produce cavities within castings (such as for engine blocks and cylinder heads used in cars), negative forms are used to make cores. Casts of this nature are usually produced in sand molds. Cores are inserted into the casting box after the pattern is removed.

Casting for light weight and strength

Aluminum’s properties of light weight and strength bring fundamental advantages when cast into parts. One common application of die cast aluminum is thin-walled enclosures with ribs and bosses on the interior to maximize strength.

Casting in the early history of aluminum

The first commercial aluminum products were castings such as decorative parts and cookware. Though produced through a centuries-old process, these products were considered new and unique.

Aluminum Casting 101

The process of casting aluminum

Casting is the original and most widely used method of forming aluminum into products. Technical advances have been made, but the principle remains the same: Molten aluminum is poured into a mold to duplicate a desired pattern. The three most important methods are die casting, permanent mold casting and sand casting.

Die casting

The die casting process forces molten aluminum into a steel die (mold) under pressure. This manufacturing technique is normally used for high-volume production. Precisely formed aluminum parts requiring a minimum of machining and finishing can be produced through this casting method.

Permanent mold casting

Permanent mold casting involves molds and cores of steel or other metal. Molten aluminum is usually poured into the mold, although a vacuum is sometimes applied. Permanent mold castings can be made stronger than either die or sand castings. Semi-permanent mold casting techniques are used when permanent cores would be impossible to remove from the finished part.

Sand casting

The most versatile method for producing aluminum products is sand casting. The process starts with a pattern that is a replica of the finished casting. Virtually any pattern can be pressed into a fine sand mixture to form the mold into which the aluminum is poured. The pattern is slightly larger than the part to be made, to allow for aluminum shrinkage during solidification and cooling. As compared to die and permanent mold casting, sand casting is slow process but usually more economical for small quantities, intricate designs or when a very large casting is required.

Casting Applications

Widespread use in the automotive industry and homes

The automotive industry is the largest market for aluminum casting. Cast products make up more than half of the aluminum used in cars. Cast aluminum transmission housings and pistons have been commonly used in cars and trucks since the early 1900s. Parts of small appliances, hand tools, lawnmowers and other machinery are produced from thousands of different unique aluminum casting shapes. The casting product most often used by consumers is cookware, the first aluminum product that was made available for everyday use.

http://www.aluminum.org/industries/processing/castings