Precious metal amorphous AgAuSi: Alloy design by swapping gold for silver

•New family of AgxAu85-xSi15 amorphous alloys for 20 < x < 60 is synthesized by co-sputtering.•Temperature dependence of electrical resistance indicated small amounts of nanocrystalline phase confirmed by HRTEM.•All alloys exhibit high hardness, 2% of elastic strain and 1–2% of tensile plasticity when tested on polymer substrates.•Complex chemistry-properties and structure-properties relationships of the alloy family are elucidated.