Hardening of the Grey Cast Iron through the Vibrating Electrode Method Using a WC Electrode and in Combination with TiC and Ti Electrode - PERJU, Manuela Cristina; NEJNERU, Carmen; RAILEANU, Tudor; AXINTE, Mihai; HOPULELE, Ioan (The Annals of “Dunarea de Jos” University of Galati. Fascicle IX, Metallurgy and Materials Science, 2008)