Friction Sintering of Copper Powder Using a New Rapid, Cost Effective and Energy Efficient Process

Dendritic electrolytic copper powder was sintered using a newly developed friction sintering process. Green copper pellets of 14 mm height and 16 mm diameter were prepared at room temperature with 5-ton load and 60 seconds holding time. The pellets were sintered using a newly developed rapid, cost-effective, energy efficient, green friction sintering process that allows for easy and quick removal of sintered products. An aluminum plate of 14 mm thickness and 16.1 mm diameter through hole was used to hold green pellets during sintering. Frictional heat and pressure were applied on a top plate through a rotating 18 mm diameter, flat shoulder, WC tool. Sintering was performed at 12 kN axial load and 800 rpm tool rotational speed. Sintering temperatures were measured using K-type thermocouples. SEM (scanning electron microscope) images of fractured surfaces for sintered pellets show neck formation between copper particles. The neck formation is approximately uniform throughout the depth. This is in-line with hardness results along the thickness of the pellet. The process holds promise particularly for solid-state sintering of metal based powders.