Precision Gears with Sintered Cr Materials

A sintered prototype gear has been manufactured via powder metallurgy route consisting of pressing, sintering, gear rolling and case hardening. The powder mix used was Hipaloy CrL™+0.2C, a particular Fe-1.5Cr-0.2Mo mix allowing achievement of 7.55 g/cm³ in sintered density by single pressing and single sintering. The prototype sintered gear reached gear quality of DIN 7 or better for all characteristics, except for profile deviations. The surface finish achieved by gear rolling matched the surface finish of ground gears. The endurance limit in gear tooth bending strength reached 1200 MPa level, which is the typical level for wrought reference gears.