Wetting and infiltration of zirconium diboride by copper and copperboron alloys

Purpose This paper investigates wetting and infiltration of zirconium diboride by copper and copperboron alloys in order to more effectively create electrodes for electrical discharge machining. Designmethodologyapproach A high temperature furnace outfitted with a video recording system was utilized to observe wetting angles between molten copper alloys and zirconium diboride at various temperatures. A parallel, investigation of the thermodynamics involved with oxidation in the system was also undertaken. Findings This study showed that zirconium diboride can be wet by pure copper under carefully controlled conditions where oxygen contamination is minimized, and that the wetting angle increases with increasing temperature. Thermodynamic calculations reinforce the contention that oxygen contamination is the key barrier to wetting and infiltration. The addition of boron to copper significantly improves the wetting characteristics, and enables wetting and infiltration under higher oxygen contamination conditions. Practical implications This study illustrated that boron must be added to copper to achieve infiltration when surface oxides are present. Originalityvalue Infiltration of porous 3D green shapes of ceramics and metals is a common method for producing metal and ceramic components using rapid prototyping. Good wetting of the porous material by the infiltrant material is necessary for successful infiltration using capillary forces. This paper illustrates the alloys and conditions under which it is possible to produce electrodes of zirconium diboridecopper using rapid prototyping.