- ‘FORMNEXT 2024’, Reading Trends in Global Additive Manufacturing Technology
The author has been the CEO of GODTECH Co., Ltd., which researches and develops materials and processes in the additive manufacturing field, since 2004, having passed through the Welding Technology Research Institute and the Industrial Gas Turbine Development Center in the domestic shipbuilding and marine engineering sector.
The purpose of visiting FORMNEXT, held at the Frankfurt Messe from November 19 to 22, was to understand the current trends in technology development in the additive manufacturing market to predict the upcoming future of the additive manufacturing market.
Having conducted research and development on metal materials and manufacturing processes for 20 years, I focused on the types and production methods of powders currently developed and applied to parts manufacturing, particularly in terms of metal powder materials, and I aimed to observe the technology development trends of the Powder Bed Fusion (PBF) process.
PBF technology is one of the additive manufacturing technologies, which lays down powder materials in thin layers and selectively fuses them using energy sources such as lasers or electron beams, stacking them layer by layer to create the final parts.
PBF technology is classified into various types depending on the energy source and material used; in this paper, I would like to specifically introduce the L-PBF (Laser Powder Bed Fusion) method that uses lasers as a heat source and the EBM (Electron Beam Melting) method that utilizes electron beams, focusing on metal materials.
■ Shrinking EBM, Rising L-PBF
The temperature difference between EBM and L-PBF technologies, which are regarded as the two main pillars of metal PBF additive manufacturing, was starkly evident at this FORMNEXT. The only exhibiting companies related to EBM technology were Colibrium Additive (formerly GE Additive) and JEOL, making it safe to say that L-PBF technology had a dominant presence.
EBM technology uses high-power electron beams to fuse metal powders, and despite the disadvantage of requiring a vacuum environment for electron beam utilization, it has the advantage of being able to layer ultra-high-temperature alloys and pure titanium, which are difficult to layer using PBF methods due to high-power beams.
Additionally, rapid beam movement allows for crack control through preheating during the layering process, and the energy source can be used in a point-source manner rather than a line source, indicating a low dependency on supports, making it recognized a few years ago as the only alternative technology for high-melting-point metal additive manufacturing.
However, with advancements in L-PBF technology, layering technology has been developed for titanium alloys and difficult-to-layer ultra-high-temperature alloys that were once believed could only be layered using EBM. Furthermore, in the fields of copper and aluminum, various L-PBF additively manufactured parts utilizing laser technologies have been produced, making metal additive manufacturing at this FORMNEXT feel more like an exhibition for L-PBF.
It was impressive that the majority of powder companies from China and Japan, including Sandvik, Höganäs, BOHLER, and Carpenter, who participated in this FORMNEXT as metal powder material companies, showcased and introduced powder materials for additive manufacturing specialized in stainless steel, nickel-based ultra-high-temperature alloys, titanium, copper, aluminum, and more.
Advancements in Technology for Producing Large Parts with Difficult-to-Layer Materials such as Copper, Aluminum, and Ultra-High-Temperature Alloys
Development of Metal Powder Production Equipment Specializing in Additive Manufacturing with High Variety and Low Volume, Increasing Price Competitiveness
■ Realizing the Large-Scale Production of Parts through Equipment Expansion in L-PBF
One of the biggest downsides of PBF technology is that the size of the powder bed determines the size of the additive structure. As such, it has strengths over relatively smaller and complex shaped additive structures compared to other additive manufacturing technologies, but there is a strong perception that it faces difficulties in scaling up.
However, at this FORMNEXT, equipment capable of producing parts larger than 820x820x1200mm with powder beds and exhibitions of equipment that can be equipped with up to 8 lasers showed that the limitations on the size of the structures were being overcome. Additionally, it was discovered that there has been significant development to overcome differences in additive speed compared to processes that utilize wires.
From the perspective of materials, for copper and aluminum, which were difficult to layer due to low laser absorption rates, the introduction of L-PBF equipment utilizing green lasers or blue lasers has confirmed the advancement of laser optical system technologies for additive manufacturing.
■ Full-scale Development of Technology for Powder Alloy Design and Recycling
What was impressive in the field of metal powder for PBF was that optimized equipment has been developed to design alloy compositions suitable for additive manufacturing, in order to overcome the disadvantages arising from conventional metal powder alloy compositions based on forged or cast materials.
Amazemet introduced equipment capable of producing intermediate materials and powders specialized in small lot production of various types using plasma. It appears capable of responding to low-melting-point powders such as copper and aluminum as well as high-melting-point powders. Additionally, it presented equipment capable of not only re-sphering powders degraded by lasers during the L-PBF additive manufacturing process or those that did not achieve a spherical shape during manufacturing but also of recycling them, highlighting the feasibility of metal powder recycling.
Not only manufacturers of equipment but also existing powder manufacturers showcased recycling technology at their exhibition booths. Existing powder material manufacturers, such as Sandvik and BOHLER, displayed promotional materials labeled Recycle Powder in front of their booths, hinting that they were conducting their own technology development to solve the problems of high prices and material supply issues for powders used in additive manufacturing.
The reflection from this exhibition is that "the world is indeed vast, and there remains much to be done!"
I got the impression that what was once thought of as next-generation technology in additive manufacturing technology has now established itself as a leading technology of this generation. I feel it is more critical than ever to close the technological gap through collaboration on materials, equipment, and process technologies in Korea in line with the development trends of advanced companies leading the field of advanced manufacturing technology.
Source: New Materials Economy http://www.amenews.kr/news/view.php?idx=60012 [Editorial Department]