Framework for cemented tungsten carbide drill bit prototype fabrication using laser engineered net shaping

Abstract

The interest in additive manufacturing and its unique applications has increased significantly over recent years. This has resulted in the need for alloys and composites to be optimized for these processes. In this study a multiphase parameter refinement framework was developed to guide optimization, and a cemented tungsten carbide alloy was used as a means of validation. Laser engineered net shaping (LENS™) was used to fabricate thin walls, cubes, and a functional prototype, namely a drill bit. The circularity, depth and diameter of the drilled holes were benchmarked against a commercially available drill bit, and finite element modelling simulations were performed to illuminate regions of high stress and indicate possible fracture zones. The circularity of the resultant holes was found to be consistent for the respective drill bits except when the drill bit tip failed and tore material from the walls of the hole. The depth and diameter of the drilled holes varied across the tests and the depth was significantly less for the fabricated drill bits compared to the commercial drill bit. The framework allowed for the functional prototype to be fabricated in 23.5 hours of active laser time. A second iteration of the refinement stage or redesign of the component could lead to improved drilling performance and will be considered in future studies.