Report

Teaser, summary, work performed and final results

Periodic Reporting for period 2 - EBMPerform (High-quality, high-speed EBM 3D printing by the integration of high-performance electron sources)

Teaser

Metal powder bed “3D printing”, or additive manufacturing (AM), enables the production of metallic parts in a resource efficient manner. Parts, such as aero-engine components, can be designed to give lighter, energy-efficient structures and designers are given freedom...

Summary

Metal powder bed “3D printing”, or additive manufacturing (AM), enables the production of metallic parts in a resource efficient manner. Parts, such as aero-engine components, can be designed to give lighter, energy-efficient structures and designers are given freedom beyond the constraints of conventional manufacturing processes.

Electron beam melting (EBM) is an AM technology that uses an electron beam to melt powder into 3D printed parts. It has been developed in Europe by Arcam, with machines being sold since 2006. The EBM process has been successfully adopted for producing medical parts, such as implants, in pure titanium or titanium alloys such as Ti6Al4V (Ti64). Ti64 is a mixture of titanium, vanadium and aluminum. These materials are processed in the EBM vacuum chamber at rather moderate working temperatures, around 600-700 C.

However, the aero-industry has not yet fully adopted EBM for production. The demands for using other alloying metal materials are high, materials that will work in extreme environments where they are subjected to high pressure and heat. When processing such materials, the working temperature in the EBM chamber must be raised to almost 1000C. This will impose new and much tougher requirements on the EBM technology. For example, reproducibility problems and the lack of a quantified measure for process quality assurance need to be overcome to qualify EBM for such demanding application.

The objective of this project is to develop the next generation of Arcam EBM 3D printers. A new improved and more robust electron beam generating source will be developed in combinations with new process controlling routines. This will enable 3D printing of complex geometries in metallic materials, which are not possible to manufacture efficiently by todays systems.

This project aimed to increase the performance of the electron beam melting (EBM) process in terms of the electron beam’s robustness and capacity. The project is a success with results providing excessive value to the Arcam organization. The results will increase the performance of EBM and strengthen the competitiveness of Arcam, considerably.

Work performed

The initial work of the project has provided us with new insight in the physics about the new electron beam sources. The gained knowledge has lead us to the conclusion about what kind of new electron beam source we should aim for. The design and the development of the new beam source has started, as well as the development of new control systems.

The integretion of the new beam source with an Arcam EBM system has been planned for and pilot studies will be conducted.

We have also developed new tools for how to calibrate high power electron beams, new models and mathematics for controlling the melt process and new and improved heat models for manage the overall heat distribution the build.

The main achievements can be summarised as follows:

A new cathode based EB unit has been developed and tested. The new unit is considerably more stable over time than existing systems and the life time of the cathode is expected to be 2-3 times longer as well. A first version of the new cathode based EB unit is expected to be available on EBM system in late 2020 or in 2021.

New software solutions for controlling and calibrating EBM machines have been developed. These solutions have already been implemented and they will become available for costumers in late 2019.

Tools for simulation and process optimization have also been developed. Mainly as prototype implementations. GPU versions are now being implemented and expected to be ready in 2020. For the time being it is possible to use the proto-type versions directly together with the machine controlling software. It will also be possible to use the GPU versions in the same way.

Final results

The progress beyond the state of the art so far are in three areas mainly:
The new automatic high power, beam calibration methodology. This will allow us to control the electron beam in a much better way than in present system
A new very fast thermal simulation technique for modelling the temperature generated when the electron beam interacts with the material.
A new voxel based, 3D heat model with effective material properties for heat mapping of complete builds

Each of these achievements have been presented as posters at the Electron Beam Additive Manufacturing conference EBAM 2018 in Nuremberg.

The expected results at the end of the project is a new EBM system working with a new type of electron beam source. The system will be able to fabricate materials at a high working temperature. The electron beam source will be stable over long time and insensitive for evaporation and ion bombardment.
The EBM process will be much more effective and more stable for working with high temperature demanding applications. The expected impacts of the research are:
Improve reliability and enable the adoption of EBM for mass manufacturing of complex metal parts made by materials that will work in extreme environments where they are subjected to high pressure and heat.

Substantial reduction of material wastage and a reduction of material usage for metal parts

Reduction of energy consumption for planes and reduction of CO2 emissions from flight related to fuel savings

Website & more info

More info: http://bmperform.com.