US 5,293,923 A · Process for metallurgically bonding aluminum-base inserts within an aluminum casting

Abstract

A method is provided for forming a metallurgical bond between an aluminum-base insert and an aluminum-base casting material during a casting process, wherein the method entails wetting the oxide surface of the insert, coating the surface with a metallurgically compatible material, and raising the temperature of the insert to reduce the temperature gradient between the insert and the casting material. The insert is dipped into a molten zinc-base alloy which includes about 2 to about 10 weight percent aluminum. The zinc-base alloy coats the insert and remains on the surface of the insert until a molten casting material is introduced. As a result, the surface of the coated insert is nearly oxide-free. The aluminum content in the zinc-base alloy is preferably about 4 to about 6 weight percent of the zinc-base alloy. The zinc-base alloy also preferably contains between about 0.25 and 0.35 weight percent magnesium for the purpose of weakening the oxide film layer on the insert. As a result, both the zinc-base alloy and the casting material can more readily wet the surface of the insert to achieve a good metallurgical bond therebetween. The residual zinc-base alloy layer fuses to the surface of the insert and the casting material. The method of the invention is equally applicable to magnesium-base alloys and composites.

Claims20

Dependent claims

A method for forming a metallurgical bond between an aluminum-base or magnesium-base insert having an oxide film formed thereon and an aluminum-base or magnesium-base cast member, wherein said method comprises the steps of:

providing a molten zinc-base alloy consisting essentially of about 2 to about 10 weight percent aluminum and about 0.1 to about 0.5 weight percent magnesium, with the balance being essentially zinc;
immersing said insert in said molten zinc-base alloy so as to form a zinc-base coating on said surface of said insert, said insert being immersed in said molten zinc-base alloy for a predetermined length of time which is sufficient to raise said insert to a temperature which is above the liquidus temperature of said molten zinc-base alloy and below the liquidus temperature of said insert;
placing said insert in a mold;
and
introducing into said mold a molten casting material selected from the group consisting of aluminum-base and magnesium-base alloys, such that said zinc-base coating substantially remains between said insert and said molten casting material;
whereby said zinc-base coating sufficiently remains on said surface of said insert, such that said oxide film on said insert is weakened so as to promote a metallurgical bond between said insert, said zinc-base coating and said molten casting material.

3 more elements

A method for forming a metallurgical bond between an aluminum-base or magnesium-base insert having an oxide film formed essentially everywhere thereon and an aluminum-base or magnesium-base cast member, wherein said method comprises the steps of:

providing a molten zinc-base alloy consisting essentially of about 4 to about 6 weight percent aluminum and about 0.25 to about 0.35 weight percent magnesium, with the balance being essentially zinc;
immersing said insert in said molten zinc-base alloy so as to coat said insert with said molten zinc-base alloy to form a coated insert, said insert being immersed in said molten zinc-base alloy for a predetermined length of time which is sufficient to raise said insert to a temperature which is above the liquidus temperature of said molten zinc-base alloy and below the liquidus temperature of said insert;
placing said coated insert in a mold;
and
introducing into said mold a molten casting material selected from the group consisting of aluminum-base and magnesium-base alloys, such that said molten zinc-base alloy substantially remains between said insert and said molten casting material;
whereby said zinc-base alloy sufficiently remains on said surface of said insert, such that said oxide film on said insert is substantially weakened so as to promote a metallurgical bond between said insert, said zinc-base alloy and said molten casting material.

3 more elements

A method for forming a metallurgical bond between an aluminum-base insert with an oxide film formed thereon and an aluminum-base cast member, wherein said method comprises the steps of:

providing a molten zinc-base alloy consisting essentially of about 4 to about 6 weight percent aluminum and about 0.25 to about 0.35 weight percent magnesium, with the balance being essentially zinc;
immersing said aluminum-base insert in said molten zinc-base alloy so as to coat said aluminum-base insert with said molten zinc-base alloy to form a coated insert characterized by said oxide film being substantially weakened, said aluminum-base insert being immersed in said molten zinc-base alloy for a predetermined length of time which is sufficient to raise said aluminum-base insert to a temperature which is above the liquidus temperature of said molten zinc-base alloy and below the liquidus temperature of said aluminum-base insert;
placing said coated insert in a mold;
and
introducing into said mold a molten aluminum-base casting material such that said molten zinc-base alloy substantially remains between said insert and said molten aluminum-base coating material;
whereby said zinc-base alloy sufficiently remains on said surface of said insert, such that said oxide film is substantially weakened so as to promote a metallurgical bond between said insert, said zinc-base alloy and said molten aluminum-base casting material.

3 more elements

Dependencies are inferred from the claim text.

Process for metallurgically bonding aluminum-base inserts within an aluminum casting

Life of this patent

Process for metallurgically bonding aluminum-base inserts within an aluminum casting

Life of this patent

Abstract

Claims20