Method of minimizing the size of primary silicon in Al-Si alloy

Details Method of minimizing the size of primary silicon in Al-Si alloy Method of minimizing the size of primary silicon in Al-Si alloy

2002-03-05

2003-04-29

Elve, M. Alexandra (Department: 1725)

Metal founding

Process

Shaping liquid metal against a forming surface

C164S057100

Reexamination Certificate

active

06554053

ABSTRACT:

BACKGROUND OF THE INVENTION
This invention relates to a method of minimizing the size of primary silicon (Si) in Al—Si alloy.
Common aluminum alloys always may be classified by compositions, mechanical properties and typical applications depending upon their composing elements. Al—Si alloy, however, is characterized by relative high fluidity in a molten state, low contractibility and melting point, and high molding characteristics. Accordingly, recent attention has been given to Al—Si alloy.
According to an aluminum-silicon phase diagram, as shown in FIGURE, an Al side is an eutectic composition which consists of Si and &agr; phase in which Si is not solidified.
Consequently, if the composition is coarse and rough, a casting material will be decreased in working ability.
In order to prevent the above disadvantage, usually phosphorus (P) has been added into molten Al—Si alloy so as to minimize the size of primary Si.
When phosphorus (P) is added into molten Al—Si alloy, Al in the molten alloy combines with P to form AlP. The formed AlP constitutes a nucleus of primary Si. It is necessary to raise the temperature of the molten alloy up to above 100° C. from the temperature of primary crystal formation. If not so, it is difficult to form AlP.
If the temperature of molten alloy is raised excessively, a large amount of hydrogen gas is melted into the molten alloy and forms pin-holes in a casting product.
When melting aluminum alloy is poured into a metal mold at low temperature, it has the hazard of shrinkage cavities in a casting aluminum alloy.
OBJECTS OF THE INVENTION
In view of the above, a main object of the invention is to provide a method of minimizing the size of primary silicon in Al—Si alloy which may easily be operated and available for good casting products.
It is a further object of the invention to provide a method of minimizing the size of primary Si in Al—Si alloy without having shrinkage cavities in a casting product.


REFERENCES:
patent: 5106436 (1992-04-01), Alabi
patent: 5253625 (1993-10-01), Donahue et al.
patent: 5283131 (1994-02-01), Mori et al.
patent: 5303682 (1994-04-01), Donahue et al.
patent: 6200396 (2001-03-01), Laslaz et al.

Affiliated with

Also associated with

Rating

Method of minimizing the size of primary silicon in Al-Si alloy does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Method of minimizing the size of primary silicon in Al-Si alloy, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method of minimizing the size of primary silicon in Al-Si alloy will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-3044364