In this work we report consolidation and erosion behavior of TiB2-Cu nanocomposites showing increased stability during electric erosion in high-current arc discharge. Composite powders containing nanoparticles of titanium diboride distributed in copper matrix were synthesized using high-energy ball milling and then shock wave consolidated to obtain fully dense compact electrode material with retention of the size of particulate inclusions. Copper weight losses by evaporation in composite electrodes were 10 times lower compared to pure copper electrodes and arc spot size was about an order of magnitude increased indicating distribution of arc on a larger surface. Porous Cu-depleted layer was formed on the surface of composite electrode and no copper melt was observed to squeeze out on the surface so that the electrode held its shape and size. The improved erosion resistance of the electrode material is believed to be due to its nanocomposite structure. (c) 2005 Springer Science + Business Media, Inc.