| abstract |
An electrostatographic developer mixture comprising finely-divided toner particles electrostatically adhering to the surface of highly shape-classified low carbon hypereutectoid steel carrier particles, the steel carrier particles comprising carrier cores having a composition comprising about 95.0 to 99.0 parts iron, 0.1 to 2.0 parts carbon, 0.5 to 2.0 parts manganese, 0.5 to 2.0 parts silicon, 0.03 to 0.1 parts aluminum, 0.01 to 0.05 parts phosphorus, and 0.02 to 0.05 parts sulphur, said carrier cores having been heat treated to a tempered martensitic microstructure with an average hardness of 40-55 Rockwell C and then overcoated with a coating material capable of electrostatically releasing toner particles adhered thereto to an electrostatic latent image. Processes of employing said developer mixture in electrostatographic imaging systems are also disclosed. |