US Patent 7644750 Method of casting components with inserts for noise reduction

The invention provides a method for manufacturing a powertrain component enclosure member, including the steps of: (A) positioning at least one insert into a mold, wherein the insert is provided with a coating to prevent bonding between the insert and the casting material; and (B) casting a wall of the powertrain component enclosure member in the mold around the insert such that a major portion of the insert is substantially non-bonded with the casting material to provide a proper interfacial boundary with the casting material for damping.