I couldn't achieve this with just three charges. Vicious of Slaughter seems to take four.
With a bronze hammer, Powerful re-forging, inspired artifice, Vicious of Slaughter, 4 charges I got a useful weapon.
Hit Energy Area 70%, Swing Speed Increase 30%, Damage Increase 40%.
I'll try copper again.
edit - found some copper hammers. Eventually made a Hit Energy Area 70% , Damage Increase 40% using powerful re-forging, inspired artifice, Vicious of Slaughter, 4 charges.