Patent ID: 11890672
Assignee: GM GLOBAL TECHNOLOGY OPERATIONS LLC
Field: Materials, metallurgy (Chemistry)
Classification: CPC B | IPC B

Claim 0:
1. A method of making a die cast part, the method comprising:
providing a negative cast mold comprising an interior surface defining a cavity to form the die cast part, the mold comprising a bore formed through the interior surface at an interior opening of the bore, the bore having an inner wall and being in fluid communication with the cavity;
providing an insert pin comprising a first portion extending to a second portion, the first portion comprising a magnetic core having a magnetic field and a barrier disposed about the magnetic core, the second portion disposed in the bore such that the first portion extends from the interior opening to the cavity;
melting a first metallic material at a predetermined temperature to define a molten metallic material, the first metallic material comprising one of aluminum alloy and magnesium alloy, the first metallic material having 1 weight (wt) percent (%) iron (Fe) to 2 wt % Fe;
filling the mold with the molten metallic material such that the molten metallic material is in contact with the first portion of the insert pin to define a contact layer of the molten metallic material;
modifying Fe content within the contact layer by way of the magnetic field of the magnetic core to define an outer layer and an inner layer formed between the outer layer and the first portion;
cooling the molten metallic material to define a solidified metallic material having dimensions of the die cast part, the inner layer having 3 wt % to 5 wt % Fe and the outer layer having 0.01 wt % Fe to 0.5 wt % Fe;
detaching the insert pin from the solidified metallic material; and
removing the inner layer from the solidified metallic material to provide a hole formed by the outer layer thereof defining the die cast part.