C12 Porous Alumina Cover Plates are highly planar, and have a porosity of about 38% which permits gasses that evolve during sintering to pass easily through the plate, while keeping parts flat and distortion-free. Composed of high purity (99.5%) aluminum oxide, C12 Porous Alumina Cover Plates will not stain contact surfaces. C12 Porous Alumina Cover Plates can be used in conjunction with C12 Separator Powder (SPS) Sheets to help prevent sticking and damaging ceramics with precious metal thick films. Other custom porous cover plate materials, including magnesium oxide (MgO) and zirconia, are available upon request.
Setters containing alumina or silica (SiO2) have adverse chemical reactions with many important technical materials including lithium-based solid electrolytes used in batteries, solid oxide fuel cell (SOFC) components that contain lanthanides and transition metals, nickel manganese compositions used in ferrites, piezoelectric ceramics and capacitors, dental zirconia, metal injection molded (MIM) compositions, and alloys that contain titanium or tungsten. Alumina-based setters also have poor thermal shock resistance and a tendency to exhibit excessive thermal creep or “slumping” at temperatures higher than about 1500°C, particularly in the porous form.
In addition to keeping parts flat and distortion-free, C12 ZrO2-Coated MgO Plates provide a smooth, non-reactive porous surface that prevents sticking and cracking. C12 ZrO2-Coated MgO Plates are highly planar, and have a porosity of about 38% which permits gasses that evolve during sintering to pass easily through the plate. C12 ZrO2-Coated MgO Plates are composed of a high purity MgO core with a patented ZrO2 coating on each face that will not delaminate or spall, even after repeated use.
Due to the fact that MgO has a melting temperature which is significantly higher than any other common oxide ceramic (>3100 K), C12 ZrO2-Coated MgO Plates resist warping better than standard alumina or other stabilized zirconia plates, and typically have a longer service life.