A method of investment casting includes casting a liquid nickel- or cobalt-based superalloy in an investment casting mold. The superalloy includes an yttrium alloying element that is subject to reactive loss during the casting. Loss of the yttrium is limited by using a zircon-containing facecoat on a refractory investment wall in the investment casting mold. The facecoat contacts the liquid nickel- or cobalt-based superalloy during the casting. Prior to the casting, a zircon-containing slurry is used to form the facecoat. After solidification of the nickel- or cobalt-based superalloy, the refractory investment wall is removed from the solidified superalloy.

A method of investment casting includes casting a liquid nickel- or cobalt-based superalloy in an investment casting mold. The superalloy includes an yttrium alloying element that is subject to reactive loss during the casting. Loss of the yttrium is limited by using a zircon-containing facecoat on a refractory investment wall in the investment casting mold. The facecoat contacts the liquid nickel- or cobalt-based superalloy during the casting. Prior to the casting, a zircon-containing slurry is used to form the facecoat. After solidification of the nickel- or cobalt-based superalloy, the refractory investment wall is removed from the solidified superalloy.

A castable refractory material for use in the manufacture of refractory products including fused silica, ceramic fiber, microsilica and a bonding material comprising colloidal silica.

A castable refractory material for use in the manufacture of refractory products including fused silica, ceramic fiber, microsilica and a bonding material comprising colloidal silica.

A castable refractory material for use in the manufacture of refractory products including fused silica, ceramic fibre, microsilica and a bonding material comprising colloidal silica.

A castable refractory material for use in the manufacture of refractory products including fused silica, ceramic fibre, microsilica and a bonding material comprising colloidal silica.