Abstract: A method for manufacturing a gear includes forming a bi-material billet from a steel cylinder having a cylindrical wall, a first end closed with a first steel cap, and an open second end distal to the first end. The method includes disposing a core material other than steel into the steel cylinder, welding a second steel cap onto the steel cylinder to form the bi-material billet, and heating the cylindrical wall. The method includes a first forging blow on the heated billet or on a disk-shaped rough forging forged from the heated billet with a first closed blocker die to produce a partial toothed preform, and a second forging blow on the preform with a second closed blocker die to produce a netshape gear. The first closed blocker die has a die cavity including gear tooth forms, and the partial toothed preform includes a plurality of spaced gear teeth.

Abstract: A method for manufacturing a gear includes forming a bi-material billet from a steel cylinder having a cylindrical wall, a first end closed with a first steel cap, and an open second end distal to the first end. The method includes disposing a core material other than steel into the steel cylinder, welding a second steel cap onto the steel cylinder to form the bi-material billet, and heating the cylindrical wall. The method includes a first forging blow on the heated billet or on a disk-shaped rough forging forged from the heated billet with a first closed blocker die to produce a partial toothed preform, and a second forging blow on the preform with a second closed blocker die to produce a netshape gear. The first closed blocker die has a die cavity including gear tooth forms, and the partial toothed preform includes a plurality of spaced gear teeth.