On the effect of equal-channel angular pressing on the mechanical properties and microstructural evolution of 18 kt goldWednesday (26.09.2018) 11:45 - 12:00 S1/01 - A3 Part of:
An important requirement for the manufacturing of design-based, small scale structures in the jewelry industry is a high strength of the precious metals. It is therefore potentially attractive to further increase the strength of precious metals like gold alloys. In this study we use equal-channel angular pressing (ECAP) to deform an 18 kt gold alloy. The material was processed at RT in a laboratory-scale ECAP-tool with an internal angle of 90° and some applied backpressure. The material was deformed in a solid solution heat-treated condition to improve the mechanical properties in combination with subsequent (post-ECAP) aging. We systematically varied the true plastic strain (by varying the number of ECAP passes) to characterize its effect on microstructure and mechanical properties. Our results demonstrate that ECAP results in a fine-grained microstructure and in a considerable increase of hardness by almost 50 % when compared to the conventionally used condition. Furthermore, we show that ECAP leads to accelerated precipitation kinetics resulting in maximum strength and considerably reduced aging times. These results highlight the potential of thermo-mechanical treatments by severe plastic deformation of precious metals to produce high strength materials for the jewelry industry.