An experimental and FEA investigation of near-net-shape cold forging of spur gear

Abstract

Cost, quality and production rate are important in gear manufacturing industries. Near-net-shape gear forging process reduces material wastage and requires less material removal processes. The near-net-shape forged components have good dimensional accuracy, continuous grain flow lines, superior strength and no voids (gas pockets). However, Near-net-shape forging of gear has certain drawbacks such as high forging load to feel the corner of the gear tooth, intricate die design and higher tonnage capacity of the press machine compared to the other conventional forging. Further, the ejection of the forged component is difficult because of the high forging load. The present work focuses on reducing forging load by removing sharp corner filling and providing relief hole. The ejection problem is overcome in proposed die arrangement. Experimental investigation of near-net-shape forging of gear (pure aluminium) is carried out at room temperature to study forging load and grain flow lines. The result of finite element analysis (FEA) simulation software (DEFORM-3D) is compared with experimental results and found good agreement. Material flow pattern and velocity distribution are checked at various punch stroke. Mechanical properties such as effective strain, effective stress, effective strain-rate and velocity are extracted at twenty one tracking points on forged gear surface. FEM simulation is also carried out on engineering alloy steel material AISI 8620 at 980 °C hot forging temperature.