Wire and Arc Additive Manufacturing : Topology Optimised Vehicle Component

Sammanfattning: Wire and arc additive manufacturing (WAAM) is a manufacturing method using a numerical controlled motion system and a welding system to additively manufacture three dimensional components. The motion system is programmed from three dimensional computer aided design model data (3D-CAD) of the intended geometry which is then sliced in to layers and welded on additively. There are seven process categories within additive manufacturing (AM), each with their own benefits and drawbacks. One of these process categories is directed energy deposition (DED) which uses an energy source to melt material onto a build plate. Instead of filling the build plate with material and selectively melting or sintering the material, DED only deposit material which is to be melted. WAAM is a process within the DED process category. BAE Systems Hägglunds manufactures relatively large components with requirements for mass reduction. Hägglunds has therefor invested in a WAAM laboratory, for testing and investigation on how to utilize this technology to their advantage. During the master thesis a geometrical correlation between the overhang angle and the material deposition on the edges of the overhangs has been found. A slicing strategy utilising this correlation has proven useful in combatting an issue where the top surface of a parallelepiped ends up unwantedly not parallel to the substrate plate. This master thesis has also increased the capability from 30° to 45° overhang angle. A numeric simulation of cooling times in the WAAM process has been developed. The simulation had a maximum error of one minute or about 69 % longer measured than simulated cooling time at worst case.