Bimetallic casting

Patent metadata

Field	Value
Publication number	US-9358608-B2
Application number	US-201414172018-A
Country	US
Kind code	B2
Filing date	Feb 4, 2014
Priority date	Oct 12, 2010
Publication date	Jun 7, 2016
Grant date	Jun 7, 2016

Abstract

A method of forming a casting includes providing a preform to a mold cavity. The preform is formed from one of a first metal and a second metal and defines an interface surface. A molten portion of the other of the first metal and the second metal is cast into the mold such that the molten portion proximately contacts the interface surface of the preform. An interface layer at the interface surface, a first portion defined by the mold cavity and the interface layer, and a second portion defined by the interface layer, are formed during casting. The interface layer may define a metallurgical bond between the first portion and the second portion. In the non-limiting example provided herein, the first portion is substantially comprised of aluminum and the second portion is substantially comprised of magnesium. In a non-limiting example, the casting may be configured as a vehicle wheel.

First claim

The invention claimed is:

1. A method of forming a casting adaptable for use as a wheel, the method comprising:
inserting a preform into a mold cavity, wherein the mold cavity is defined by a mold surface of a mold;
positioning the preform in the mold cavity using one or more locating elements to form a continuous gap between the preform and the mold surface;
wherein the preform is formed from one of a first metal and a second metal;
wherein the preform is defined by an outermost surface;
wherein the continuous gap is coextensive with the outermost surface;
pouring a molten portion of the other of the first metal and the second metal into the continuous gap such that the molten portion entirely encapsulates the outermost surface of the preform to completely separate the preform from the mold surface;
solidifying the molten portion to form the casting including:
an interface layer coextensive with the exterior surface of the preform;
a first portion having an exterior surface defined by and coextensive with the mold surface; and
a second portion including the preform and defined by the interface layer.

2. The method of claim 1 , wherein the interface layer further includes a metallurgical bond formed between the first portion and the second portion.

3. The method of claim 1 ,
wherein the first portion is substantially comprised of one of aluminum and an aluminum alloy; and
wherein the second portion is substantially comprised of one of magnesium and a magnesium alloy.

4. The method of claim 1 , wherein the casting is adaptable for use as a wheel for a vehicle.

5. The method of claim 1 , wherein the interface layer further includes an intermetallic compound comprising the first metal and the second metal.

6. The method of claim 1 , wherein the preform is one of a casting, a forging, an extrusion, a stamping and a spun component.

7. The method of claim 1 , wherein the preform is operatively configured as a heat sink.

8. The method of claim 1 , the first portion is characterized by a thickness defined by the mold cavity and interface layer, and wherein the thickness varies along the interface layer.

9. The method of claim 1 , wherein the casting defines a wheel bore of the wheel.

10. The method of claim 1 , wherein the casting includes a plurality of openings; and
wherein the plurality of openings define at least one spoke of the wheel.

Assignees

• Gm Global Tech Operations Inc

Inventors

• Carlson Blair E
• Krajewski Paul E

Classifications

• B22D19/16 Primary

  for making compound objects cast of two or more different metals, e.g. for making rolls for rolling mills (casting compound ingots B22D7/02) · CPC title

• B22D19/00

  Casting in, on, or around objects which form part of the product (B22D23/04 takes precedence; alumino-thermic welding B23K23/00; coating by casting molten material on the substrate C23C6/00) · CPC title

• B60B2360/104

  Aluminum · CPC title

• B60B3/02

  with a single disc body integral with rim · CPC title

• B60B3/06

  formed by casting · CPC title