11.4 (a) Sterling silver is an alloy of silver with 7.5 per- cent copper. Describe the structure that one should expect if a specimen of sterling silver were to be heated from room temperature to 782C and allowed to come tO equilibrium at this latter temperature. (b) If the specimen of sterling silver equilibriated at 782 C is now cooled very slowly to 400C, what would be the nature of the microstructure? Give the amount and com- position of each phase. (c) Finally assume the specimen is cooled very rapidly (quenched) from 782C to 400C. Describe the structure that one might expect.