Influence of the Alloying Time on the Hardness and the Electric Resistivity of PCL/Pure Copper Materials Produced by the Mechanical Alloying Process

摘要

Mechanical alloying process (hereafter abbreviated as MA) is applied to polycaprolactone (PCL) /Cu powder mixture, in order to develop the copper base material with the characteristics of degradation in ground. The mean value as well as the dispersion of hardness decreases with increasing MA time. The value of hardness scarcely coincide with the theoretical prediction based on the law of mixture as MA time increase. The electric resistivity increases with increasing MA time up to the level depending on the copper content. The value at saturation decreases as the copper content increases. SEM observation shows that copper particles remain as the aggregates at shorter MA time and the particles wrapped by PCL disperse homogeneously at longer MA time. This indicates that the electric conduction and the force transmission originate from the aggregates at shorter MA time, and that no electric conduction and force transmission originate from the dispersed particles at longer MA time.