Testing P/M materials for high loading gear applications

Details of commercial rolling contact fatigue test bench are given; its des ign permits the evaluation of the rolling contact fatigue behavior of diffe rent materials, and makes if suitable for testing porous materials. Without additional machining the original as-sintered surface is tested. Elastohyd rodynamic lubrication is applied which is essential for testing porous mate rial under realistic service conditions, Using the fed bench, material beha vior under variable loading conditions con be studied allowing the life-tim e calculation for a given load-time history. following tr brief overview of rolling contact fatigue, results obtained with the test bench on wrought r ose, and P/M materials ore given and analyzed the change from "open "to "cl osed" porosity in sintered steel influences significantly endurance limit a nd this impacts the development of new, high loading structural parts such as planetary gears and camshaft lobes.