12.10.2016 Pressing & Sintering

Qualitative comparison of PM gear impact performance, equipment, methodology and results

One of the modes in which a gear can fail is through sudden shock loads, caused by for instance abuse of the transmission. Therefore the question of how PM gears can take abuse loads compared to wrought materials often arises when looking at new application for sintered gears. In the paper the development of a new equipment to test impact strength of gears is described. It is also described how the staircase method, often used to determine for instance endurance limits in fatigue testing, can be employed to determine the impact strength of a gear. Finally results for different powder metal steels at different densities and heat treatments are presented, along with a comparison of a typical wrought steel.