A preliminary study on mechanical-electrical behavior of graphite powder-filled high-density polyethylene composites

Mechanical and electrical responses of graphite powder (GP)-filled high-den sity polyethylene composites to a uniaxial compression-decompression cycle were studied. Above a compression loading level, a large positive-pressure coefficient effect of resistance was observed, for which a slide mechanism of GP in the matrix is believed to be responsible. In a step-wise compressi ve loading and loading-holding experiment, the critical compression level w as also found, at which the resistance response changed from a time-indepen dent one to a time-dependent, creep-like one. The current-voltage behavior of the composites showed that the GP contact was non-ohmic, regardless of G P contents and pressure levels. (C) 2000 John Wiley & Sons, Inc.