Study on the microstructure and properties of Au-Cu-Pt-Ag alloy strip

In this work, Au-Cu-Pt-Ag master alloy were prepared by vacuum induction melting and then the alloy strips were prepared by cold rolling. The microstructure and mechanical properties of Au-Cu-Pt-Ag alloy strips with a processing rate of 30%～70% and heat treatment at 300～700℃ were studied. As the cold working rate incresses from 30% to 70%, the alloy hardness increases from 257HV to 282HV. When the processing rate was 70%, the hardness reaches the maximum balue of 282HV. When the heat treatment temperature was above 600℃, the alloy undergoes complete recrystallization, forming uniform equiaxed crystal structure, and significantly reducing the hardness of the alloy. Aging treatment at 300℃ for 0.5h, 1h, 2h and 4h resulted in ordered transformation within the alloy phases, shrinkage of grain cell volume, and gradual coarsening of grain boundaries; As the aging time increases from 0.5 hours to 4 hours, the hardness of the alloy first increases and then decreases, the maximum hardness was 323HV at 2 hours.