Mass production of gold and platinum wedding rings usually involves blanking washers out of sheet, pressing into cones and rolling into rings or, alternatively, cutting ring blanks from lengths of tube followed again by ring-rolling. Both techniques are labour-intensive and material-inefficient. This paper describes how, for the first time, a powder metallurgical technique has been developed for large-scale ring-making, initially for a carat-gold rings but latterly for platinum. The process involves atomization of powder, cold pressing and sintering followed by rolling to the required ring size. There are both technical and economic benefits, and these are discussed.

Author: Peter M. Raw