Application and Evaluation of Current Guidelines for Metal Additive Manufacturing

Abstract

The goal of this thesis has been to evaluate the design guidelines that currently exist regarding designing for metal additive manufacturing (AM). More specifically, this project has focused on the design guidelines regarding thin-walled features and how well they work when applied to adapt an industrial part for manufacturing with the AM process laser powder bed fusion (L-PBF).
Making the walls of features as thin as possible is a very important aspect of making designs that are cost-effective to produce with AM, as it reduces manufacturing time, and the manufacturing time is one of the biggest factors contributing to the total manufacturing cost. Metal AM is comparatively expensive, and hard to apply for mass production in a financially sound way. Therefore, it is important that designs for AM take full advantage of the benefits of the technology and for that, well-developed design guidelines are needed.
In this project, an industrial part from Alfa Laval that had previously been partially adapted for AM was redesigned by following the current guidelines as closely as possible. The goal was to see how well the guidelines work when applied in a realistic scenario and where further research can be done to improve them.
Guidelines were collected from various research experiments within the AMLIGHT project (Design and Material Performance for Lightweight in Powder Bed Metal Additive Manufacturing) and literature about AM, as well as from Alfa Lavals recommendations for the part. L-PBF was also researched to understand the process the part was being adapted for.
The redesign of the part uses much less material and would thus be much cheaper to manufacture, and some insights into where the design guidelines might be further refined were had.

Popular Abstract

Mapping out the path to lighter and cheaper metal AM products

Smaller, lighter, smarter, faster, and better. Additive manufacturing promises a lot, but there is still much research to be done before the technology reaches its full potential. This thesis has played a part in taking stock of how products are designed to be manufactured using the metal AM-technology laser powder bed fusion, and how the design process can be improved.
Designing for a technology that involves shooting laser beams at tiny particles of metal dust to melt them into a complicated useful product is not easy. It requires deep understanding of how the process works. Its strengths and weaknesses. You need to know exactly where the line is between a successful print and a piece of scrap metal, and you need to be able to get right up to that line without overstepping it. Finding out where the design limits are is very important for AM, as it allows engineers to reduce manufacturing cost with smarter designs. Producing products with AM is comparatively expensive, and every small bit of cost reduction makes the technology more approachable and useful.
In this thesis project, design guidelines in use today were collected, and an industrial part from Alfa Laval was adapted for AM by following these guidelines as closely as possible, with the intention of finding out how well they work when applied in a real industrial setting by someone who has very little previous experience with AM. A special focus was on the design guidelines regarding thin walls. The amount of material needed for a product is one of the main contributing factors to the total manufacturing cost, and a good way to reduce the amount of material in a product is to make every aspect of it as thin as possible. Another is to remove all unnecessary material inside of the part, leaving thin outside shell. The thinner you can get things, the cheaper the final design will be to produce, and even small improvements can have a large impact.
In the case of this project, over 90% of the material needed to make the Alfa Laval part could be removed, and the manufacturing cost could be brought down to just one third of previous designs, proving that the current guidelines do work quite well. Some insights could also be had as to where the guidelines might need some more fine-tuning. In some cases, there might be room to push the limits a bit more, and in some there might be need for more specific guidelines.
Hopefully, the work done in this project can provide a little bit of clarity into the current state of metal AM, giving a hint to where further research could be aimed.

• author: Bergman, Robin
• supervisor: Axel Nordin; Satabdee Dash
• organization: Innovation
• course: MMKM05 20212
• year: 2022
• type: H2 - Master's Degree (Two Years)
• subject: Technology and Engineering
• keywords: additive manufacturing, laser powder bed fusion, thin-wall structures, design for additive manufacturing, design guidelines
• language: English
• id: 9089525
• date added to LUP: 2022-06-16 10:40:36
• date last changed: 2022-06-16 10:40:36