Technology maturity index
A technology on the brink of full maturity
Laser Beam Powder Bed Fusion has established itself as the leading AM technology for metal applications. The use of LB-PBF for the production of end parts in highly demanding industries such as medical, aviation and the energy sector has driven a continuous improvement of machine hardware and process reliability over the past five years. Large efforts by all major machine OEMs were taken to optimize and stabilize the gas flow, enable an easy-to-use calibration of multi-laser systems and establish an overall improvement of machine reliability. Due to these developments across all major machine OEMs, the part quality and consistency has significantly improved with the newly released LB-PBF system generation. Consequently, LB-PBF has reached the top right corner of the AMPOWER Maturity Index. Additionally, to these urgently needed improvements in machine reliability and process repeatability, to meet industrial standards and expectations, more recent developments in LB-PBF have been focusing to further increase the production speed and integration of LB-PBF in a conventional industrial set-up.
To increase production speed and reduce part cost multi-laser machines were introduced into the market nearly a decade ago. By now, most OEMs offer machines with up to 4 lasers working in parallel on the powder bed. To push production speeds even further SLM SOLUTIONS, the pioneer of multi-laser machine set-ups, introduced its newest 12-laser machine in 2020. Additionally, VELO3D announced an 8-laser system to be available in 2021 and 3D Systems partners with the US Army Research Lab to develop “the world’s largest and fastest printer”.
Accompanying the trend of higher productivity of the melting process are the general efforts to industrialize the whole digital and physical process chain. The aim is to leave the stand-alone machine set-ups and software solutions behind and integrate the LB-PBF process into industrial set-ups known from conventional manufacturing technologies. The newest machine generations are equipped with APIs to connect them to the customers MES and ERP systems to efficiently collect process information for KPI analysis. Parallel to the developments of machine analytics software from the OEMs, all major software providers are working on AM specific solutions to further integrate the machines into the customers CAD/CAM and resource planning tools. Additionally, to the industrialization of the digital process chain, the LB-PBF OEMs are working on factory set-ups connecting multiple machines among each other and with essential post-processing steps such as unpacking, heat treatment and separation from base plate. ADDITIVE INDUSTRIES already integrates the “whole” process chain into its MetalFAB1, while 3D SYSTEMS, EOS, GE ADDITIVE and SLM SOLUTIONS have presented concepts on how to connect single process steps to an automated process chain.
Wide adoption through all high value metal verticals
Design and applications
High design freedom only limited by support structures
Materials and alloys
Laser Beam Powder Bed Fusion material variety
For LB-PBF a large variety of alloys is commercially available. The most important prerequisite is a good weldability. Furthermore, the material must be available as a powder with a suitable particle size distribution. The powder fraction is system and process specific and differs between about 20 µm to 60 µm. With an adaptation of process parameters larger as well as finer powder fractions are possible, too. Very fine powder fractions tend to agglomerate during handling and coating due to extremely fine dust particles in the distribution and should be avoided.
Typical alloys processed with LB-PBF are Ti-6Al-4V, CoCr, stainless and tool steels, nickel-based superalloys, aluminum alloys and also precious metals. High purity copper is difficult in processing with today’s machine systems as the available laser wave lengths is only poorly absorbed.
Typical material properties for LB-PBF exceed ISO standard for surgical implants
Advantages and disadvantages
Cost as the remaining threshold for a wider adoption
The main benefits of LB-PBF technology are the good mechanical properties of the resulting parts, their high density and the fine resolution. The technology is well-established with a large variety of available metal alloys. It is a single-stage production that enables a high freedom of design. Scrap material is reduced through near net shape production and recycling of the unmelted powder.
However, internal residual stresses that are induced during cooling constitute a restriction since they can lead to part deformations or cracks. Support structures to counteract such stresses have to be removed after the building process. The relatively rough surface, moreover, typically requires several post-processing steps. The investment costs for machine systems as well as the feedstock material are considerably high and may pose a limiting factor on potential business cases.