Leachable ceramic materials for use in casting

Supports for supporting mold parts and/or cores in investment casting, comprising a leachable support material comprising:

• a mechanically supportive continuous matrix phase comprising alumina;
• at least one second phase interpenetrating the mechanically supportive continuous matrix phase and providing a pathway for leachants to penetrate into the material,
• wherein the supports are dimensioned to support the mold parts and/or cores in investing casting, and wherein the leachable support material comprises:
• in the range of 1 wt. % and 12 wt. % of the second phase, and the second phase interpenetrates the matrix and provides a pathway for leachants to penetrate into the material;
• and
• less than 15 vol. % voids;
• wherein a first material used to form the mechanically supportive continuous phase in the supports has a first particle size distribution including a first d50 and a second material used that form the second phase in the supports has a second particle size distribution and a second d50 such that the second phase is uniformly distributed throughout the matrix phase, providing leachability and strength of the supports;
• and
• wherein the first d50 is greater than the second d50.