Forming of hollow gear-shafts with pressure-assisted injection forging (PAIF)

Hollow gear-shafts were formed with a radial extrusion configuration, which involves the use of polymers as the pressurising media—pressure-assisted injection forging (PAIF). The process was qualified with definition of the forming-limit diagrams established with reference to three typical loading paths (histories of the injection and pressurisation). Forming was effected with the qualified procedures and pressurizing media. The results demonstrated feasibility to form hollow gear-shafts with the PAIF process carefully designed and controlled. Applications of the processing technology could significantly reduce the cost of manufacturing thick-walled tubular components with hollow secondary elements, such as flanges with tooth geometries.