Summary-Reader Response Draft #1
The ARCAM EBM Spectra H is
an advanced electron beam melting (EBM) 3D printing system developed by GE
Additive, specifically designed for high-temperature materials such as titanium
aluminides and Alloy 718 which are known to be crack-prone. (OpenAI 2024). The
Spectra H is part of the ARCAM EBM series, which is known for its capability to
produce parts with high density and mechanical properties that are comparable
to wrought materials.
The machine is the new top-of-the-line EBM printer
that does additive manufacturing better than past models. Its size is 1328 x
2344 x 2858mm (D, W,H) and its build volume is 250 x 430mm (D, H). The typical
process temperature range is 600 to 1100 degrees Celsius and the max beam power
is at 6kW. It is commonly used in the aerospace, medical and automotive
industries where complex high-strength metal parts with intricate and tight
tolerances are essential. (Griffiths 2018).
The machine can recover unused powder in a closed
environment as when a part is cleaned after manufacturing the excess powder is
recovered and passed through a magnetic sieve to remove other unwanted foreign
objects. The powder is then returned to the hoppers via the hopper filler
station. The system operates in a close-looped controlled atmosphere to prevent
contamination and oxidation during manufacturing, ensuring the final product's
quality. (OpenAI 2024)
(Gokuldoss, Kolla, Eckert 2017) states that
Electron Beam Melting (EBM) is akin to Selective Laser Melting (SLM) in its
layer-by-layer fabrication approach. However, EBM differs in using an electron
beam for powder particle fusion, maintaining high powder bed temperatures (>870
K), and requiring overnight cooling. EBM involves numerous process parameters
such as beam power, scanning velocity, and plate temperature, making
optimization challenging. Limited materials like Ti grade 2, Ti6Al4V, Inconel
718, and CoCrMo are used due to their complexity. EBM is slow and costly, with
size limitations for parts and lattice structures. Parts larger than the
substrate plate can be made, but the initial layers must be smaller. EBM
operates in a vacuum, preventing oxidation and minimizing porosity. However,
volatile alloy constituents like Zn, Mg, Pb, and Bi are not recommended.
Electron Beam Melting (EBM) offers an advantage
over Selective Laser Melting (SLM) in processing brittle materials like
intermetallics, which are prone to solidification cracks due to rapid cooling.
In SLM process they generally use higher cooling rates which makes brittle
material form cracks easily. While in EBM, the powder bed temperature can be
raised to around 870 K, facilitating slower cooling rates and preventing
solidification cracking. This allows for the processing of materials like TiAl
and high entropy alloys without crack formation. The electron beam can be used
multiple times to selectively melt parts, significantly increasing processing
time per layer compared to SLM. Additionally, considerable cooling time, often
overnight, is required for the chamber and parts to reach room temperature
before removal from the substrate plate. This is one of the reasons why EBM is
highly sought after in this day and age of addictive manufacturing (Gokuldoss,
Kolla, Eckert 2017).
The Arcam EBM Spectra EBM H has an extended build platform which is
39% bigger than previous models which makes it easier to produce bigger and
more parts. It can produce parts at temperatures exceeding 1,000 °C which
allows it to use high temperature, crack-proof materials, and movable heat
shields to create improved insulation that confines heat in the build space,
forming the ideal environment for exceptional part production, an auto-calibrated,
6 kW beam provides a 100% increase in power to provide up to 50% faster builds
(Boissonneault 2018).
The machine has a closed-loop system that maintains powder integrity by using a
Powder Recovery Station (PRS), an auto-dosing sieve and a hopper filler
station. When a new part is built inside the machine excess is recovered from the part, and smaller
particles are separated in a cyclone separator. Additionally, a magnetic sieve
is used to remove any metallic particles picked up during cleaning. The recovered
powder is then returned to the hoppers via the hopper filler station. The
system operates within a closed-loop environment, ensuring that powders are
contained and not exposed to external elements, preventing cross-contamination.
(Arcam, E. B. M. Spectra H)
In conclusion, Electron Beam Melting (EBM) technology, exemplified by the Arcam
EBM Spectra H, marks a significant advancement in additive manufacturing. Its
precise electron beam control enables the fabrication of complex metal parts
with exceptional accuracy and strength. The Spectra H's closed-loop system
ensures efficient powder management, mitigating contamination risks and
maximizing material utilization. Its ability to create a dust-tight environment
enhances safety and product quality. EBM holds promise across various
industries, including aerospace and medical, where intricate designs and
high-performance components are paramount. As EBM technology evolves, its
applications will likely expand, revolutionizing manufacturing processes worldwide.
References
Arcam, E. B. M. Spectra H. (n.d.). EBM_Spectra H_Bro_4_US_EN_v1.pdf (ge.com)
Boissonneault, T. (2018, May 19) GE Additive new ARCAM EBM Spectra H metal AM system delivers 50% faster build speeds.
Griffiths, L. (2018). Hot metal - a closer look at GE Additive’s Spectra H
Electron Beam Melting System. https://www.tctmagazine.com/additive-manufacturing-3d-printing-news/hot-metal-ge-additive-spectra-h/
Gokuldoss J.K, Kolla S, Eckert J. (2017, June 19) Additive
Manufacturing Processes: Selective Laser Melting, Electron Beam Melting and
Binder Jetting—Selection Guides. Materials | Free Full-Text |
Additive Manufacturing Processes: Selective Laser Melting, Electron Beam
Melting and Binder Jetting—Selection Guidelines (mdpi.com)
OpenAI. (2024, January 22). Conversation with ChatGPT3.5 https://chat.openai.com/
Comments
Post a Comment