Majid Khodadadi - Department of Mechanical Engineering, University of Birjand, Birjand, Iran
Khalil Khalili - Department of Mechanical Engineering, University of Birjand, Birjand, Iran
Amir Ashrafi - Department of Mechanical Engineering, University of Birjand, Birjand, Iran

Flowforming is a plastic deformation process that is used to produce precise thin-walled tubes. Manufacturing of an internal gear through flowforming process is a new method by which the gear can be manufactured in just one pass. In the present study, the flowforming of internal gear is studied both experimentally and numerically. A simple set up was designed and built to manufacture the internal gear. The plastic behavior of the material was determined through tensile testing, and the friction condition was determined using a friction test. Parameters including profile and teeth height were measured and compared with simulated values. It is shown that there is a good agreement between the results of the simulation and those of the experiment. When the simulation is verified, the design of the experiment method is employed to investigate the influences of roller diameter, feed rate, thickness reduction percentage and attack angle on the process force. According to DOE results, all parameters and interactions are significant and affect the process force except D×T. The process force increases by increasing the roller diameter, thickness reduction percentage and feed rate, but decreases by increasing the attack angle.

Flowforming, Internal gear, Finite Element Analysis, Design of experiments, Optimization