Work hardening wrought copper

Platinum work-hardens at approximately the same rate as palladium or copper, a 25% cold reduction in thickness raising the hardness from about 40 HV in the fully annealed state to 75 HV. Cast platinum is usually slightly harder than the same grade of metal in the wrought and annealed state. 

Fig. 3.1-132 Effect of work hardening, expressed as % reduction in thickness by rolling, on the mechanical properties of CuZnlS brass. This relation is a typical example for the control of the mechanical properties of wrought copper alloys by work hardening...

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