Study on Recyclability of Graphite Cutting Chips as Conductive Fillers

The purpose of this study is to reuse graphite cutting chips as thermal and electrical conductive fillers in heat-resistant ceramics. Ceramics test pieces including graphite particles can be solidified in nonoxidization condition using packing cokes; the maximum allowable content of supplied graphite chips is 60wt%. However, better thermal and electrical properties can be obtained by refining the chip particle size below 157µm, and by making their slurry with ceramic particles and surfactant water solution before the fabrication of test pieces. The thermal and electrical properties of composite test pieces significantly improve by adding refined graphite chips up to 80wt%, but the highest thermal property is obtained with the filler quantity of 60wt%. It is deduced that sufficient heat conduction paths cannot be formed with graphite chips beyond that quantity, due to a lack of densification of ceramics to adhere graphite particles and to avoid air inclusions.