Dental Equipment 62kg 2000W 220V Zirconia Sintering Furnace

Sintering

Ceramic sintering is the process where heat, and sometimes pressure, transforms a ceramic material, reducing porosity and increasing particle density. Other properties, such as strength and translucency, are often enhanced. Pre-sintered zirconia starts out in a monoclinic crystalline structure, with a chalk-like appearance and feel that is easy to mill or contour with a slow-speed handpiece. At around 1,100°C to 1,200°C, zirconia transforms from the monoclinic structure to a polytetragonal crystalline state, increasing particle density, strength, and translucency. The chalk-like appearance and texture is replaced with an extremely hard, dense, and incredibly strong ceramic material that even a high-speed handpiece with diamond burs would struggle to cut. Sintering also causes zirconia to shrink approximately 25%.

While zirconia transforms from one structure to another at around 1,100°C to 1,200°C, most sintering furnaces fire at temperatures closer to 1,500°C. Final sintering temperatures can have a profound effect on the zirconia. Typically, the higher the temperature, the denser the zirconia b comes, usually close to 99% of the theoretical maximum density.

Prior to being placed in the sintering furnace, green-state zirconia is usually positioned in a crucible filled with zirconia beads. The beads allow for movement of the zirconia as it shrinks