Method for making a high temperature erosion resistant material containing compacted hollow geometric shapes

A method of making an insulating material used as a thermal insulating layer, comprising the steps:

• providing a first permeable extracting membrane material structure that is permeable to a liquid portion of a slurry comprising a sinterable binder but that is not permeable to a solid portion of the slurry;
• providing a second permeable structure at a distance away from the first structure thereby defining a first void between the first and second permeable structures;
• placing geometric shapes in the first void between the first and second permeable structures;
• providing an impermeable restraining structure a distance away from the second permeable structure and opposite the first structure defining a second void between the second permeable structure and the impermeable structure;
• introducing the slurry into the second void between the second permeable structure and the impermeable structure;
• applying pressure in the second void between the second permeable structure and the impermeable structure forcing the slurry through the second permeable structure and around the geometric shapes thereby filling in any voids adjacent the geometric shapes and being forced against the first permeable structure to form the insulating material;
• removing the insulating material from between the first and second permeable structures;
• and
• heating and drying the insulating material.