Lower cost, high-precision and waste reduction: the add-on of laser-based additive manufacturing

Although the use of 3D Printing in the manufacturing industry is totally integrated, what we know today about additive manufacturing (AM) is the result of three decades of research. It is a fact: the most common process for making metallic products, Laser-based additive manufacturing (LBAM), has given the industry the opportunity to develop more sustainable production and reach sectors such as medical, aerospace, automotive, jewellery, tooling, among others.

LBAM is at the “heart” of metal AM technology

Writing an article about Additive Manufacturing without mentioning a NASA project would be going against the rules: Last September, the space agency announced that the Artemis program, which will be returning astronauts to the moon, will print rocket engine parts using metal powder and lasers, using pioneering additive manufacturing methods that lower the price, print very complex parts with high precision and produce very large pieces. The advantages of using this kind of technology in the aerospace field are a game-changer for the manufacturing sector.

Before entering into more complex printing process explanations, remember the definition of AM: According to American Society for Testing and Materials, it is a “process of joining materials to make objects from 3D model data, usually layer upon layer, as opposed to subtractive manufacturing methodologies”.

The object printed, is first scanned to be digitally defined by a computer-aided-design (CAD) software. Then, the next steps depend on the type of process and technology chosen according to the material that will be used to give life to the object.

To fabricate metal parts, completely functional and functionally graded metal products, the most appropriated technique – which is “at the “heart” of metal AM technology” (Brandt, 2017) – would be the advanced production system called Laser-based additive manufacturing that uses “a laser beam to melt and solidify the material in a powder-bed according to slices of a corresponding three-dimensional computer-aided design (3D-CAD) model” (Kranz and Herzog, 2014).

Fabrication of complex geometries and multi-material fabrication combined with the principle of lean manufacturing

“The predominance of laser-based processes (SLS/M, LENS, LOM) shows the wider utility and acceptability of lasers in AM”, says Kumar and Pityana (2011). Different types of techniques are applied with LBAM:

• Powder or wire-fed or laser metal deposition (LMD and LENS) is typically used to repair metallic components by using a “laser beam to form a pool of melted metal on the surface of a metallic substrate into which metal powder is injected using a gas stream”(SPI Lasers).

• Powder bed or selective laser melting (SLM): “A layer of powder (with a controlled thickness) is spread over the building platform. The powder bed is sintered or molten selectively by the laser beam deflected by a galvanometer scanner. The building platform is lowered by a height corresponding to one-layer thickness defined at the step”(Inside Metal Additive Manufacturing)

• Wire feed system (WLAM): “The WLAM system normally consists of a laser, an automatic wire-feed system, a computer numerically controlled worktable or a robot system and some accessorial mechanisms (e.g., shielding gas, preheating or cooling system). The laser generates a melt pool on the substrate material, into which the metal wire is fed and melted, forming a metallurgical bound with the substrate” (Ding, Donghong, et al., 2015).

According to ZMP Institute (Zentralinstitut für neue Materialien und Prozesstechnik), the Laser Beam Melting (LBM) and Laser Metal Deposition (LMD) processes are unique with abilities such as fabrication of complex geometries (e. g. undercuts) and multi-material fabrication respectively.

In the case of Viseam, one of the application experiments of AMable, an additive manufacturing project under the I4MS umbrella, the use of powder bed fusion/selective laser melting Manufacture casing for vibration sensor used in Machines Prognostics’ health monitoring system, Foresight: “VISEAM drives the idea of vibration sensor cases that are done by additive manufacturing for use cases where individual shape and fixing is needed”.

Additive manufacturing and Artificial Intelligence: the perfect match

Artificial Intelligence (AI) can improve all stages of an additive manufacturing workflow by reducing errors and facilitating automated production, guaranteeing accuracy and repeatability. It can create the model as a CAD file, prepare for printing in a slicing software, and print the object.

The manual tasks can be managed by AI, such as data collection, cost tracking, planning construction, it also can help to optimize the production, the machine utilization and the planning production.

TU Delft University used AI to create materials that were extremely compressible, yet durable. The following video presents an overview of how additive manufacturing can be combined with AI processes.

The use of Machine learning, a subset of AI, in the process of printing is another important step for the manufacturing industry, since it eliminates systematics errors that can appear and not been previously identified. See the case of Inkbit, a start-up of MIT, which has been combining Machine Learning with 3D Printing.

Despite AI and 3D printing encouraging innovation, making production more dynamic and increasing the competitive distance with other companies,the entire Additive Manufacturing process cannot be yet handed totally to Artificial Intelligence.

LBAM, a game-changer in the manufacturing sector

Lean Manufacturing (LM) is another perspective of Advanced Manufacturing focused on minimizing the waste of raw materials while simultaneously maximizing productivity. According to Yoshida, the late 80’s concept’s objective is to build better to reduce waste and make continuous improvement in large enterprises.

In Laser-Based Additive Manufacturing non-conventional innovative materials can be used, giving a more efficient approach to industrial production and enabling the creation of lighter and stronger parts and systems, most of the time using low-cost materials. There are no doubts that Additive Manufacturing is on its way to revolutionize the manufacturing sector: “The processes are useful for making once-off product (spare parts), customized and complex products, low volume production and cheap high-value products (medical implants).

There are also certain products which were impossible through conventional means such as mould with conformal cooling channel could be conveniently fabricated. These have found applications notably in the following fields: medical, aerospace, automotive, jewellery and tooling” (Kumar and Pityana, 2011)

In the specific case of Laser-Based Additive Manufacturing, the greater obstacle of laser technology for AM is still its cost. This is when European projects such as PULSATE with a consortium of 9 partners can help to bring closer the laser technologies to SMEs by consolidating a strong Pan European network. The project believes that LBAM promises high productivity, high quality, high speed, and high flexibility, enabling new designs and concepts in manufacturing can be introduced in SMEs by covering the technologies and the competences needs but also the business part. The programme aims to mobilize at least 200 SMEs to participate in open calls. You can join the PULSATE community here.

Nevertheless, the list of advantages that the application of AM brings is getting bigger and bigger according to the evolution of the technologies. Time, waste and money spent are reduced in an important number of processes (Attaran, 2017). A lot of manufacturing sectors could revolutionize everyday life with the use of additive manufacturing. The next step in the manufacturing sector is around the corner.

Marjorie Grassler In-house consultant @MWCapital #manufacturing #additive-manufacturing