Closed-Die Forging of Gear Like Element.(Dept.M)

Mohamed Shabara,A El-Domiaty,M Al-Ansary

doi:10.21608/bfemu.2021.160711

Abstract

Closed die forging of spur gears is investigated using the slab method and the upper bound technique. The tooth regions are approximated by prismatic rectangular sections. The velocity field comprising three unit deformation regions is used. A constant frictional stress between workpiece and forging die is assumed. The average punch pressure normalized by the flow stress of the gear material is determined theoretically and compared with experimental results. The experimental work is carried out on a commercial pure aluminum (Al 1100) at room temperature. The forging process is carried out using one die geometry without using any additional blocker (preform) dies. The theoretical predictions of forging pressures and deformation configurations agree fairly well with the experimental results.

Highlights

With the use of closed-die forgjng. complex shapes and heavy reductions can be made within closer dimensional tolerances than are usually feasible with open dies
The analysis showed that the velocity field which leads to the best load prediction is not that which most closely describes changes of geometry in a billet
These results are transferred to be in the form of relative average pressure versus reduction in height to make possible the comparison between the theoretical results, by both slab and upper bound method, and the experimental results

Summary

INTRODUCTION

With the use of closed-die forgjng. complex shapes and heavy reductions can be made within closer dimensional tolerances than are usually feasible with open dies. In closed-die forging, a material must satisfy two basic requirements: low flow stress and high forgability. Large deformation behaviour of aluminum and -low carbon steel short ~s loaded axially in a ~imple compression test without using any lubricant was examined by Gupta and Shah [6]. Their results reve.aJed that the profile of a deforming specimen can be approximated by an arc of a circle only after the onset of folding. In the present work both the upper bound technique and the slab method have been used to analyze the closed-die forging of a spur gear. To determine the validity of the present anaJysis. an experimental program is carried out on commercially pure aluminum (AJ 1100) billets to forge a spur gear having twelve teeth

SLAB METHOD ANALYSIS

RESULTS AND DISCUSSION

CONCLUSION