The development of 990 gold — titanium: Its production, use and properties

Abstract

Pure gold with only one per cent of titanium may well be the only significantly different new jewellery and coinage alloy developed in recent times. In this paper, an account is given of the development of a 990 fineness gold alloy with good colour, durability and mechanical properties, and why titanium was chosen as the alloying metal. Methods are described for the alloy’s production, solutionizing and age-hardening. Mechanical properties are given as a function of deformation, age-hardening time and temperature for three different starting states. These properties are compared with those of some standard 14 and 18 carat jewellery alloys and pure gold.