Microstructures of rapidly solidified Cu-Hf alloys

Rapidly quenched Cu-Hf alloys were prepared by melt spinning as 35-55 mu m thick ribbons and microstructure was examined as a function of alloy content and subsequent ageing. It was found that up to about 0.3 at.%Hf can be retained in solid solution across entire ribbon thickness. At higher alloying contents two morphologically different zones were formed across ribbon section. Increase in hafnium content or addition of chromium and silver improved thermal stability of microstructure which allowed maintaining good properties after high temperature annealing.