In order to recycle Al2O3 substrates from waste ceramics, the Al2O3 substrate was crushed by attrition and an alumina compact with cullet was made by infiltration. Another alumina compact with cullet was made by PLPP (pressureless powder packing forming method) and firing. During crushing, the particle size depended on speed and time of attrition. Crushing efficiency decreased with time. To confirm the behavior of cullet infiltration using the crushed powder, an infiltration device was prepared. The use of cullet as a flux proved to be difficult at temperature in the range of 1100~1300oC because of it's high viscosity. Therefore, borax was added and the infiltration distance increased many dozens times at over 15 wt.% of borax and 1150oC, and alumina compact was prepared by a mixing preform method and PLPP. After making an alumina compact, densification behaviors and characteristics were observed at a sintering temperature of 1150oC. For PLPP, the binder solution of 4 wt.% PVA solution was infiltrated into the packed powder to obtain a suitable strength of compacts, and silicon rubber was used as a mold because of its good releasing property. For the alumina compact formed with cullet by PLPP at 1150oC- 2hr, the structure of the alumina bonded by an amorphous phase was observed and as the content of cullet increased in the alumina compact, so the porosity decreased. Addition of 10~40 wt.% of cullet gave 30~40% of the porosity.

Keywords: Al2O3 substrate, preform, PLPP, flux, cullet, Borax