One embodiment is a method. The method includes providing a casting apparatus including a first chamber and a second chamber, wherein the first chamber is isolated from the second chamber. The method includes charging an alloy composition into a crucible present in the first chamber and melting the alloy composition in the crucible to form a molten alloy composition. The method includes discharging the molten alloy composition into a casting mold present in the second chamber; applying a positive pressure to the first chamber to create a first chamber pressure; and applying a vacuum to the second chamber to create a second chamber pressure, wherein the first chamber pressure is greater than the second chamber pressure. The method further includes casting a filament or a turbine component from the molten alloy composition in the casting mold. An apparatus for casting a filament or a turbine component is also provided.