Failure analysis of 3D-printed steel gears

Abstract

The basic principle of additive manufacturing technology is that the model can be manufactured directly via computer-aided design system. This technology is quite different from traditional methods and allows production to avoid wasting material.This study features 420 steel gears produced using both additive and conventional manufacturing. The gears were subjected to identical test processes and compared to one another. The effects of rotational speed, torque, production technique, and post-production surface treatment were investigated. The researchers performed wear loss, efficiency analysis, oil analysis, damage analysis, optical, and scanning microscope surface analysis. It was revealed that the density and hardness of the gears produced by additive manufacturing (Direct Metal Laser Sintering – DMLS) were quite close to those produced by conventional methods (hobbing machine); however, the surface properties were different. Therefore, the types of damage that occur under the same operating conditions differ. As a result, it was found that gears produced by additive manufacturing wear more, but the weight loss (which is a measure of wear) from wear was mostly caused by non-sintered powders. However, under the same operating conditions, it was found that production technique has little effect on efficiency. In some conditions, the performance of the gears produced by additive manufacturing (with a smoother tooth profile) was better from the computer-aided design. It was also seen that surface treatment after additive manufacturing has a preventive effect on gear wear and damage.