Strain stress diagram for sterling & 14k gold

We are a small company developing new technology (automation and
robotics) for the jewelry trade. We are searching for mechanical
properties of silver sterling silver abd gold. We can get all the
necessary from the graph/ diagram of the stress strain of
these metals. We are aware that it these data depends on the alloys
too but we would like to get and idea. Especially important for us is
the Yield point when the metal starts it plastic deormation.

Thank you vrey much
Kind regards,
Michael Racinef