Patent ID: 7137433

Claim:
A device for producing a lightweight part comprising an inner core comprising a metal foam, a dense core surface layer that is metallically joined to the inner core, and an outer wall comprising an essentially pore-free cast metal layer that is at least one of positively engaged with the dense core surface layer and surrounding the inner core and metallically joined to the dense core surface layer and surrounding the inner core, the device comprising: a first casting mold that forms the inner core, wherein the inner core is created in the first casting mold by forming the dense core surface layer, forming the inner core of a metal foam, and metallically joining together the inner core and the dense core surface layer; a second casting mold that forms a finished part, wherein the finished part is created by removing the inner core from the first casting mold, positioning the inner core in the second casting mold, feeding a melt material into the second casting mold, allowing the melt material to solidify so as to form the outer wall, and removing the second casting mold; and a pressure device which can pressurize a first melt material disposed in a melt vessel, wherein the pressure device comprises a gas inlet system that includes nozzle parts projecting into the first melt material, wherein, during forming of the inner core, the gas inlet system is located vertically below a feed opening arranged at a bottom end of the first casting mold, and wherein during forming of the inner core, the first casting mold is connected to a portion of the melt vessel so as to allow the first melt material to pass up through the feed opening.