microstructure of CuAg

CuAg forms a simple eutectic phase diagram. Hence various hardening mechanims can be adopted:

• solid solution strengthening
• grain boundary hardening
• precipitation hardening
• work hardening

Discontinuous precipitates are always connected to a boundary. In the case of CuAg alloys they start at high angle grain boundaries. Two routes are traced to suppress their formation: 1) Increase the eutectic phase to a level where the Cu matrix grains are not in contact anymore (this holds for Cu25Ag) and 2) modify the grain boundary by the addition of a insoluble element like Zr. This suppresses the diffusion along the grain boundary and hence enhances the formation of continuous precipitates.

Research on Cu-7Ag-0.05Zr alloys has been carried out for a couple of years. Here are the details:

• formation of precipitates in CuAgZr
• energetics of the precipitation reaction in CuAgZr
• thermal treatments of CuAgZr alloys
• TEM of CuAg alloys
  
• fatigue of CuAg alloys
• strength of CuAgZr alloys
• magnetoresistance of CuAg alloys
• first coil wound from CuAgZr