Electron Beam Melting (EBM) Archives - Perfect 3D Printing Filament

Exactech Transitions from EBM to Laser 3D Printing Implants for Shoulders

Orthopedic implant device maker Exactech wants to scale up the production of its Equinoxe Stemless Shoulder implant by switching from electron beam metal additive manufacturing to direct metal 3D printing with high precision lasers. In an official statement released on July 21, 2020, the Florida-based company announced plans to transition all US stemless shoulder procedures to its laser-printed devices throughout the rest of the year.

As the latest addition to the company’s extremities product line, the Stemless Shoulder, launched in 2018, is a bone conserving prosthesis designed for anatomic total shoulder arthroplasty. Comprised of a stemless cage, humeral head, and cage glenoid, the device offers intraoperative flexibility which is ideal for conserving the bone, said the company. Furthermore, to enhance the probability of biological fixation, it incorporated a laser 3D printed porous bone cage structure that allows bone-through growth, and without the need for a stem, there is more ease of implantation, reduced operating time, and blood loss. Exactech indicated that the innovative combination of 3D porous material and bone cage technology is what differentiates it from competing products on the market.

The new Equinoxe Stemless Shoulder uses laser-printed AM (Image courtesy of Exactech)

Currently, there is a growing trend towards minimally invasive orthopedic surgeries, like stemless shoulder implant procedures mainly led by experts in Germany and France. However, US surgeons also took notice of the benefits of using stemless implants to perform arthroplasties with less bone removal and fewer complications than more conventional anatomic shoulder prosthesis.

Driven by an upsurge in the aging population, longer life expectancy, and rising prevalence of arthritis, the global shoulder arthroplasty market is expected to reach $2.4 billion by 2023, and that includes increased demand for stemless shoulder implants, as forecasted by Koncept Analytics last year. In the US alone, over 53,000 people have shoulder replacement surgery each year, according to the Agency for Healthcare Research and Quality, and with only a handful of stemless shoulder implants cleared by the US Food and Drug Administration (FDA) since 2015 (including the Equinoxe Stemless Shoulder), there is a wide-open market opportunity for medical device manufacturers to exploit. Expecting to become a leading force in the stemless implant market, Exactech is switching technologies to deliver quick solutions for patients and surgeons.

“We have been incredibly pleased with our original EBM [electron beam melting] Stemless Shoulder implant and the early positive clinical feedback we received from our surgeon customers. The new laser-printed device is built on this solid foundation while also giving us the ability to ramp up production to serve even more patients, which drives us and fulfills our mission,” said Exactech Vice President of Extremities, Chris Roche.

Orthopedic surgeons Curtis Noel, of the Crystal Clinic in Akron, Ohio, and Stephanie Muh, of the Henry Ford Health System in Detroit, Michigan, were the first shoulder specialists to perform the surgeries with the Equinoxe Stemless Shoulder implant earlier this month. As a member of the design team, Noel expressed how proud he was to be one of the first to implant the laser-printed Stemless Shoulder, mainly due to the bone conserving design, along with its compatibility to the Equinoxe Shoulder Platform System.

Laser 3D printed porous structure designed to promote bone-through growth (Image courtesy of Exactech)

Muh described that “one of my favorite features of the Stemless implant is its bone cage structure that is designed to provide initial press-fit fixation while also allowing for bone-through growth. That intentional design element, along with the porous structure being designed to mimic the trabecular nature of cancellous bone, differentiates it from competitors.”

In order to design the Stemless Shoulder implant, Exactech engineering researchers collaborated with orthopedic surgeons that combined their knowledge, expertise, and background to come up with a final design structure that could be additively manufactured with optimized pore size, porosity, and count. The design team included Noel; shoulder and elbow surgery expert’s Felix Henry Savoie, from Tulane University, and Joseph Zuckerman from New York University (NYU)’s Langone Orthopaedic Hospital; Pierre-Henri Flurin, from the Clinique du Sport in Bordeaux-Mérignac, in France; Ryan Simovitch, the Director of the Shoulder Division at the Hospital for Special Surgery (HSS) in West Palm Beach, Florida, and Thomas Wright, Director of Interdisciplinary Center for Musculoskeletal Training at the University of Florida.

Pre-operative X-ray (left) and postoperative X-ray (right) showing the laser-printed Stemless Shoulder and Equinoxe Cage Glenoid. (Image courtesy of Stephanie Muh)

As a developer, and producer of innovative implants, instrumentation, and computer-assisted technologies for joint replacement surgery, Exactech targeted clinical evaluations of the Stemless Shoulder immediately after release and has been aggressively expanding and upgrading its product ever since. Just like other manufacturers of stemless implants, the goal here is to try to reproduce the native shoulder anatomy and minimize humeral bone removal. Recent studies. have outlined the numerous advantages – as well as a few disadvantages – of stemless shoulder implant arthroplasty, and although its use is still emerging outside of Europe, the implant is gaining ground with surgeons and patients and is expected to surpass stemmed implants by 2025.

The post Exactech Transitions from EBM to Laser 3D Printing Implants for Shoulders appeared first on 3DPrint.com | The Voice of 3D Printing / Additive Manufacturing.

China: 3D Printed Vertebral Body Used to Reconstruct Upper Cervical Spine of 9 Patients

Primary osseous spinal tumors make up roughly 5% of all primary bone tumors, and reconstruction is required to restore the spine’s integrity and stability. However, it’s hard to reconstruct this complex section, which is responsible for transitioning the axial loading force from the cranium to the spinal column, and subpar implants can result in complications like migration and nonfusion.

3D printing can be used to fabricate patient-specific porous implants for fixing these bone defects. A group of researchers from Beijing published a study, “Upper cervical spine reconstruction using customized 3D-printed vertebral body in 9 patients with primary tumors involving C2,” where they described “the clinical outcomes of upper cervical spine reconstruction using customized 3D-printed vertebral body,” with “a mean follow-up of 28.6 months” for the patients.

“Patients with primary tumors involving C2 who were treated in our institution between July 2014 and November 2018 were enrolled,” the team stated.

“Nine patients (2 males and 7 females) were included in the study with a mean age of 31.4 years (12 to 59 years). Seven patients demonstrated tumors located in C2 and 2 showed involvement of C2 and C3.”

The nine patients initially complained of “aggravating pain,” with two suffering neurological impairment, and average duration since the onset of these symptoms was almost three months. Here’s the tumor breakdown for the patients, established using a CT-guided biopsy:

4 giant cell tumors (GCT)
2 chordoma
1 Ewing sarcoma
1 paraganglioma
1 aggressive hemangioendothelioma

Fig. 1: Imaging studies for patient #3. The achievement of osseointegration was defined when new bone formation was observed around the bone-implant interface on X-ray (B) and CT (D) during the follow-up compared to that of immediately postoperative (A,C). The postoperative segment vertebral height was measured on the midsagittal reconstruction CT from atlas anterior tubercle to the midpoint of the adjacent lower endplate (C).

Making the implants was a 7-day process. First, CT scans were performed on the patients’ spines, and the DICOM data was imported into Materialise Mimics 15.0 software, where a CAD model for the implant was designed. Ti6Al4V powder was used to print the porous metal scaffold implants with Arcam EBM’s electron beam melting technology.

“Based on our previous studies, the parameters set for the trabecular structure and the size of the uniform micro-pores were determined to generate the optimized biomechanical and osteoinductive properties (8,15,16). The upper contact surface morphology of the implant coincided with the inferior articular surfaces of C1, while the lower contact surface morphology coincided with the upper endplate of the caudal vertebra,” they wrote.

Fig. 2: The 3D printed artificial vertebral body with porous scaffold fabricated out of titanium alloy powder.

A two-stage intralesional spondylectomy was performed on each patient, and the 3D printed vertebral body was used to accomplish anterior reconstruction, without the use of a bone graft.

“The average interval between the posterior and anterior procedures was 14.4 days,” the researchers said.

“In the first 4 cases in this series, occipitocervical fixation was performed (Figure 1). Subsequently, with more confidence in the stability of the 3D-printed anterior construct, we were able to preserve the atlanto-occipital joint in the next 5 cases.”

If you’re interested in the rest of the nitty-gritty surgical details, check out the full research paper.

Table 1: The details of the 9 patients

In the table above, you can see the details of the patients, who all had follow-up appointments after the 3D printed vertebral body was implanted. All nine received postoperative radiotherapy, while two also received chemotherapy.

“Patient one died of systemic metastases 15 months postoperatively without signs of local recurrence. Patient seven had tumor local recurrence. The others were alive and functional in their daily livings at the last follow-up without evidence of disease. At their final follow-ups, the neurological status of all alive patients was ASIA E, and the average VAS score was 0.9. Three patients had ECOG 1, while 5 patients had ECOG 0 for their general well-being and activities of daily life,” they stated.

Fig. 3: Imaging studies for patient #3.

Through radiograph and CT examinations, the researchers observed new bone formation around the bone to implant contact surfaces, “which provided the evidence of osseointegration,” and they found that all of the 3D printed vertebral bodies were stable, without any signs of ” implant displacement or subsidence.” Additionally, none of the screws had come loose, and there was no rod breakage in the posterior instrumentation systems.

The researchers found several advantages to using 3D printing for this reconstruction rather than traditional methods of manufacturing, such as the implant offering “reliable primary immediate postoperative stability.” A patient-specific implant provides a better match to bony surfaces and a larger contact area, and because screw tracks are actually integrated directly into the artificial vertebra, “self-stabilization” occurs.

Fig. 4: Imaging studies for patient #6 showing fusion process. Compared to the immediate postoperative X-ray (A) and CT (D), regenerated osseous tissue can be seen to have gradually grown along the implant 12 months (B,E) and 24 months (C,F) post-op (arrow).

“Secondly, the anatomical design of the contact surface of the curved porous endplate and its biocompatibility provided reliable mid-long-term stability. The porous bone-contacting surface of the 3D-printed vertebral body is conducive to bone in-growth into the trabecular pores to achieve firm osseointegration, which was supported by evidence from previous basic research and in vivo studies (15,16,24),” they explained.

Additionally, post-op radiotherapy may not affect the 3D printed vertebral body as much, so long as osseointegration on two ends occur, “because solid combination was accomplished.” Conversely, this treatment can lead to instrumentation failure with conventionally manufactured implants.

“In our study, the progress of osseointegration is evident on follow-up with imaging studies. On lateral radiography, regenerated osseous tissue was seen adhering to the 3D-printed vertebral body (Figures 1B,4B,C1B,4B,C).),” the researchers noted. “Sagittal CT revealed new bone tissue crawling and growing around the ends of the 3D-printed vertebral body from the upper and lower vertebra (Figures 1D,4E,F1D,4E,F).). All patients were capable of resuming normal activity without mechanical pain associated with spinal instability at 12-month follow-up.”

Finally, a 3D printed vertebral body could mean there’s less of a need for transoral (direct access through the mouth) or transmandibular surgical approaches. For example, as noted above, this research team used the posterior-anterior approach to perform C2 spondylectomy, which made it easier and safer to isolate the vertebral arteries.

“Our study suggests that 3D-printed implant may be a good option in upper cervical reconstruction, the tailored shape matching with the contact surfaces and the porous structure conductive to osseointegration provide both short- and long-term stability to the implant,” the researchers concluded. “However, a higher level of evidence is still needed.”

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The post China: 3D Printed Vertebral Body Used to Reconstruct Upper Cervical Spine of 9 Patients appeared first on 3DPrint.com | The Voice of 3D Printing / Additive Manufacturing.

Kiwi Companies Partner to Build Tailored 3D Printed Training Prosthetics for Female Para-Athletes

New Zealand-based Zenith Tecnica, which is the only company in the country using Electron Beam Melting (EBM) technology to make 3D printed titanium components, is teaming up with High Performance Sports NZ (HPSNZ) to give two inspiring Kiwi athletes a competitive edge for the Tokyo 2020 Paralympics. Through this collaboration, the two companies will produce tailored 3D printed prosthetics for esteemed para-athletes Anna Grimaldi and Holly Robinson to use while working out and training in the gym.

3D printing has been used multiple times to help disabled athletes get a leg up over their competition, with prosthetics and braces as some of the main applications. As Zenith Tecnica, headquartered in Auckland, has supplied EBM 3D printed titanium components to America’s Cup Regatta and Formula 1 teams, fabricated plenty of medical instruments and implants, and manufactured components in outer space, the company was more than up to the challenge of making advanced, tailored prosthetics for Grimaldi and Robinson.

“Zenith Tecnica 3D printed the new attachment for Holly and Anna to use in the gym,” said Dr Stafford Murray, HPSNZ Head of Innovation. “It’s providing them with something different that you can’t buy off the shelf, that enables them to be the best that they can be.”

The company utilizes the Arcam Q10 plus and Q20 plus systems to produce EBM parts for multiple industries. These 3D printers are built on breakthrough deflection electronics, which allow for extremely accurate, fast beam control so melting can occur simultaneously at more than one point, while still maintaining excellent speed, precision, and surface finish. In addition, its hot vacuum process means no residual stresses to distort the 3D printed components.

“Zenith Tecnica offers a freedom of design to a lot of engineers, so we are not constrained to classical manufacturing methods like machining and casting,” explained Peter Sefont, the Production Manager at Zenith Tecnica. “It allows us and the engineers to do whatever we want.”

Holly Robinson

HPSNZ is a leader in sports innovation, and works with National Sporting Organisations (NSOs) to identify athletes’ strengths and push them further with modern technology and sports science. By partnering with Zenith Tecnica and using its EBM titanium 3D printing expertise, the company is able to think about the possibilities of design in a new way and knock down any boundaries that would otherwise limit them.

“To have someone listen to what we need and be like, ‘Nothing is off the table, we can try and build whatever it is you need,’ that was really awesome,” Grimaldi said about the teamwork between HPSNZ and Zenith Tecnica.

These two fierce female para-athletes are simply amazing. Robinson won the silver medal in the Women’s Javelin F46 at both the Rio 2016 Paralympics and the 2018 Gold Coast Commonwealth Games. She’s already thrown her personal best – 45.73 m – which was good enough to break the world record in the event at the Australian Track & Field Championships in Sydney this past weekend.

Grimaldi won the gold in the Women’s Long Jump T47 at the Rio 2016 Paralympics and came in fourth in the Women’s 100m T47 at the same competition. This coming June, both women will have an optimal opportunity to see if their new 3D printed training prosthetics can help them win at the 2019 Oceania Area and Combined Events Championships.

Raylene Bates, Athletics New Zealand high performance coach, said, “This is a piece of equipment that would enable them to train like an able-bodied person; granting the use of both arms with a full range of movement, achieving a full body balance.”

Anna Grimaldi

Of course, all of these competitions are a precursor to the main event both Robinson and Grimaldi are working towards – the 2020 Paralympics in Tokyo. The hope is that through this partnership between Zenith Tecnica and HPSNZ, their new 3D printed titanium prosthetics will help them up their game while preparing for next year’s competition. Because these will be prosthetics tailored specifically to them, exercises and training methods that the para-athletes were previously unable to do because of previous off-the-shelf prosthetics should now be entirely possible…which means that gold medals are possible as well.

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Interview With 3DInductors About 3D Printing Pure Copper Induction Coils With EBM

Recently we told you about 3DInductors. This is a new service that lets you 3D print pure copper induction coils. 3DInductors was developed by GH Induction which is a part of GH Group, based in Valencia Spain and one of the market leaders in induction heating. The company developed its own technology application for 3D printing copper based on EBM (Electron Beam Welding). This is a complex process to work with and dial in for manufacturing. In addition, copper 3D printing has been attempted before by many players only for them to find out that it is much more difficult than they think. Of the players that say that say can do it right now precious few are actually able to deliver parts at scale. What’s more, the 3DInductors team is the first to do this for EBM. Also, it is the first company able to 3D print pure copper. It’s incredibly innovative that the GH Group would go through the significant lengths to develop their own technology and then to launch a direct to customer “start up/separate brand/skunkworks” type of play to bring it to market. I think that this really shows a very fruitful path for staid and large companies to innovate.

A 3D Printed Pure Copper Induction Coil

Induction coils are used to heat conductive metals in order to harden them via induction heating. Traditionally they were made by hand but the design freedom was limited. With 3DCoil 3DInductors opens up the design space for these parts. Lower inventory and lower TCO are just some of the benefits. A very exciting thing, however, is that due to the 3D printing process the parts last up to four times longer than the traditionally made ones. The combination of these factors may see the induction heating industry forever changed.

The company uses 99.99% copper and has a very high 99.7% recycling rate. They’ve already shipped over 400 of these 3D printed coils to customers including large automotive firms such as Renault. They also 3D print quenches to go with your induction coils. The business case for this looks very solid indeed and I love innovation such as this. We reached out to the firm with more questions and Concepción (do call her Inma) Sánchez was kind enough to answer them.

Why did you turn to 3D printing?

In induction metal parts heating, coils and inductors are the core of the process. They are the end tool where the magnetic process affecting the part, or material to be heated, occurs.

After more than a century in which the dominant manufacturing process has been mainly based, upon joining technologies such as brazing or soldering, skilled coppersmithing has been the safeguard of the quality with unique knowledge and know-how. The use of fixtures, mandrels, and machined parts has improved the repeatability and quality of the produced elements but high volume, dimensional repeatability has always been a source of problems.

All manufacturers are working continuously on the improvement of such relatively artisanal methods to allow better lifetime, minimized production time and overall better quality.

GH Induction is always looking for new technologies that benefit directly to our customers. This is our main added value.

Why copper?

The raw material for inductors is copper because it is the ideal for induction heat treatment in metal parts.

Copper represents the best compromise between electrical conductivity, mechanical properties, and cost. Other material could be used but either do not match cost limitation or mechanical properties.

Was it difficult to develop a copper process?

It really was.

GH Induction performed tests and developments with the available technologies before taking a decision on LBM (Laser Beam Melting) or EBM (Electron Beam Melting). We obtained better results (melting rate, porosity level) with EBM while using copper powder than with LBM (beam reflection problem, Argon trapped). In addition, considering an industrial production approach, the EBM technology allows to stack parts one above the other.

Then we had to develop from scratch EBM with pure copper manufacturing method. That didn’t exist before with EBM (Electron Beam Melting) printing technology.

Only titanium and cobalt-chrome printing for demanding applications in mechanical properties like orthopedic implants and aerospace parts were developed so far.

GH Induction together with a research center took some years to develop the process with pure copper material.

The solution was so innovative that we have been able to patent it. We are working with it for 5 years now and we commercialize it for almost 3 years now.

It is a breakthrough in the industrial induction heating sector.

An EBM Build Plate with pure copper

What machines do you run it on?

We have several machines, all based upon Electron Beam Melting technology which utilize a high power electron beam that generates the energy needed for high melting capacity and high productivity. The electron beam is managed by electromagnetic coils providing extremely fast and accurate beam control that allows several melt pools to be maintained simultaneously (MultiBeam). The process takes place in vacuum and at high temperature, resulting in stress relieved components with material properties better than cast and comparable to forged material. Our method based on EBM is the only 3D printing method able to print pure copper. The service life is much longer, the density is higher minimizing leakages and the mechanical and electrical properties are better. LBM techniques use copper alloys and they present intrinsic drawback when considering the manufacturing of coil with pure copper:

· Limited transformation of the energy into efficient melting due to the refraction of the beam on copper
· Post treatment needed due to created stress within the part
· Risk of pollution of the element (no vacuum)
· Use of an additional element to improve powder bonding remains as one important question mark.

Do you use pure copper? Other materials?

Only pure copper at the moment but we are always researching.

Copper alloys are not suitable because the alloy elements must be removed in order to avoid rusting creation of inclusion or compound which makes the manufacturing process more complex.

A Flame Brazing Coil

What are the advantages of 3D printing copper for your parts?

The inductor is an end effector where take place the creation of the magnetic field required for the induction heating effect. That means it follows the contour of the part we want to heat. The advantage of printing copper is that we can manage complex design that before were extremely or impossible to do with a more classical method (brazed elements).

In addition, we translate directly into the printer the CAD deign we have engineered. It includes shape changes that we believe allow to obtain the best efficiency in terms of pattern and magnetic precision.

We should not forget that an inductor is a tube shaped into the form we want to give it. Tubular section variation is needed since high power density flows onto the surface and requires cooling in most cases and we are in the vicinity of a part which can top at more than 1000 deg C.

Another aspect of that technology is the high reproducibility which allows the end-user to swap inductors with no or limited setting. That brings a clear gain in time.

Schematic of the EBM Process.

How does 3D printing extend the service life of the components?

The traditional method to manufacture copper coils is to join empty copper tubes segments by brazing. These coils must be cooled to withstand the high currency flowing through them. Mechanical fatigue results with the contraction and retraction cycles due to the magnetic forces onto the copper surface during the heating phases. Then the brazed joints in a coil/inductor assembly are often the weakest points and the initiation point of the coil destruction. Using 3D printing the coil is created as a single 3D piece without brazed joints increasing dramatically the lifespan.

We have seen improvements of over 400%. However, we see an average increase higher than 100% in most cases

In addition, the design is modelled through the 3D CAD software optimizing both outer and inner design:

reducing the points with higher current density (hot spots)
improving coil cooling by changing the geometric characteristics of the inductors
Manufacturing process carried out in a vacuum atmosphere in order to avoid porosity and rusting.
High dimensional accuracy process that allows identical coil copies.
These inductors can be repaired just like the traditional ones.

How many parts do you make?

We have already hundreds of 3D inductors in-field. Depending on the induction application, meaning type of part to heat and process, we can reach different results but always better. For instance, in an automotive driveline case we get 400% more lifespan.

Imagine the operational savings for the customer:

Dramatic decrease of their part production cost
Extreme reduction of production stoppages
Less inventory

How does geometric freedom help your part performance?

There are cases where the main benefit is the ability of adaptation to the part to be heated. In these cases the conventional brazed coils for mechanical reasons cannot fit to the part for optimum heat treatment. Another big benefit is the capability to improve continuously an original coil design once it is under production. Depending on production results, inner or outer coil modifications can be introduced to improve them.

Why is this such a good fit with inductors?

No brazed joints and total design coil flexibility
Total adaptation to the part to be heated
Design continuous improvement
High dimensional repeatability
Assembled inductors cost is sometimes more economic due to the reduction of the labor needed.

Who uses your products?

Industrial manufactures from any sector using heating processes like heat treatment (hardening, tempering, …), brazing, welding, straightening, etc.
The GH 3D inductors are highly recommended to high volume productions as automotive industry and when complex parts need to be treated.

What is the goal of your business?

To be a reference in our induction heating sector and to become a global 3D inductor provider for any induction machine or system.

What kinds of companies would you be interested in working with?

With any that can clearly benefit from our technology and experience because upgrading the traditional inductors to 3D is more than printing. Experience in induction and in 3D coils is mandatory.

Researchers Complete Comprehensive Evaluation of Manufacturing Methods, Including 3D Printing, for Impellers

EDM and ECM finishing of near-net-shape turbo charger wheels produced by additive manufacturing and investment casting.

Combustion engines uses turbochargers to boost their performance. But, for multiple reasons, there isn’t a conventional process chain for economically manufacturing the component. A team of researchers from RWTH Aachen University and Robert Bosch GmbH recognized the need for a comprehensive evaluation of alternative manufacturing methods for impellers – 3D printing isn’t the only way – and set out to deliver. They published their results in a paper, titled “Technological and Economical Assessment of Alternative Process Chains for Turbocharger Impeller Manufacture.”

The abstract reads, “In this paper, different manufacturing chains consisting of pre-finishing and finishing of near-net-shape parts are compared to each other for a given example geometry. Electrochemical as well as Electrical Discharge Machining technologies are taken into account as alternatives for conventional milling and grinding processes for the finishing of cast blanks or samples produced by additive manufacturing. Based on a technological analysis a cost comparison is executed, which allows an economical assessment of the different process chains regarding given boundary conditions and varying production quantities.”

In addition to electrochemical (ECM) and electrical discharge machining (EDM) technologies, the team also looked at wire-based technology variants (WEDM/WECM) for outer straight geometries, and 3D-(Sinking)-based technologies for inner flow ones. They completed a cost comparison of the methods, based on technological analysis, which, as the researchers wrote, “allows an economical assessment of the different process chains regarding boundary conditions and production quantities.”

Turbocharger wheels – blank manufacturing by investment casting (near-net-shape and finish contour) or additive manufacturing and conventional finishing by milling and grinding

“In a first step a technological process analysis took place for both alternative primary shaping processes of turbocharger wheel blanks and for finish machining of near-net-shape geometries by conventional as well as unconventional advanced machining processes,” the researchers wrote. “Target values were a geometrical precision better than 0.05 mm and a minimum surface roughness of Rz = 4 µm.”

Fine investment casting can be used to manufacture a blank with defined material allowance, as well as electron beam melting (EBM) 3D printing, though the latter with require post processing because of insufficient geometrical precision and a rough surface. It’s possible to finish with 5-axis milling, but due to extensive tool wear, it will require a lot of effort. The team determined that abrasive flow machining and vibratory grinding would not work.

“All technological necessary efforts have been evaluated and aggregated in a production cost ratio relative to the standard investment casting process as basis,” the team wrote in the paper. “This includes tool costs (purchase costs and life time), raw material costs (melt / powder material), energy (average energy consumption) and working costs (salary and multiple machine work) as well as machine costs (investment, net book value, space, maintenance, machining time per part) for main and secondary process like hot isostatic pressing (HIP) – imperative for the EBM parts – and washing. Additional industrial boundary conditions were a yearly lot size of 150,000 parts and working time of 4,800 h. The earnings per worker amounts to 43.75 €/h, the energy price and monthly space costs are 0.128 €/kWh and 12 €/m² respectively. The imputed interest rate is 10 %.”

Production costs of different primary shaping and finish machining as well as handling processes relative to the investment casting process.

Alternative EDM- and ECM-based processes were also included in the diagram.

The researchers explained that the microstructures from 3D printing and casting processes had a major influence on the final surface roughness. In addition, the ECM-processed material was analyzed, and basic EDM research showed that for the TiAl material, the correct electrical polarity had to be clarified. By applying a new flushing concept based on WECM, the team was able to achieve higher ECM cutting rates in a “competitive order of magnitude of 20 mm²/min also for macroscopic workpiece heights.”

EDM and ECM applications for finishing turbo charger wheels.

It was determined that, under the boundary conditions laid down, 3D-EDM is not a competitive or efficient single process, but 3D-ECM is, when compared to 5-axis milling. Additionally, WEDM and WECM showed low costs.

“It can be concluded that the process chains involving 3DEDM are not suitable as their cost ratios are higher than 300 % of the reference but the ECM variants reveal significant advantages due to much lower cost ratios. In addition for the basis costs, the AM produced raw blanks reveal lower cost ratios compared to the investment casted ones – even for the given series production,” the researchers wrote.

These results are due to the specific material properties of the TiAl material. Because of low costs for the outer geometry finishing, the contour casted samples also had higher cost ratios.

“As a conclusion – for the given boundary conditions – the process chain including 3DECM and WECM of AM produced blank wheels achieved the lowest costs and was therefore the most efficient one,” the researchers wrote. “Further work should include detailed studies on surface integrity for the different machining processes and appropriate positioning.”

Co-authors of the paper are A. Klink, M. Hlavac, T. Herrig, and M. Holsten.

3D Printing News Briefs: August 24, 2018

We’re sharing some business news in today’s 3D Printing News Briefs, followed by some interesting research and a cool 3D printed statue. Meld was listed as a finalist in the R&D 100 Awards, and Renishaw has introduced 3D printed versions to its styli range, while there’s an ongoing Digital Construction Grant competition happening in the UK. A researcher from Seoul Tech published a paper about in situ hydrogel in the field of click chemistry, while researchers in Canada focused on the Al10SiMg alloy for their study. Finally, an Arcam technician tested the Q20plus EBM 3D printer by making a unique titanium statue of Thomas Edison.

Meld is R&D 100 Awards Finalist

The global R&D 100 Awards have gone on for 56 years, highlighting the top 100 innovations each year in categories including Process/Prototyping, IT/Electrical, Mechanical Devices/Materials, Analytical/Test, and Software/Services, in addition to Special Recognition Awards for things like Green Tech and Market Disruptor Products. This year, over 50 judges from various industries selected finalists for the awards, one of which is MELD Manufacturing, an already award-winning company with a unique, patented no-melt process for altering, coating, joining, repairing, and 3D printing metal.

“Our mission with MELD is to revolutionize manufacturing and enable the design and manufacture of products not previously possible. MELD is a whole new category of additive manufacturing,” said MELD Manufacturing Corporation CEO Nanci Hardwick. “For example, we’re able to work with unweldable materials, operate our equipment in open-atmosphere, produce much larger parts that other additive processes, and avoid the many issues associated with melt-based technologies.”

The winners will be announced during a ceremony at the Waldorf Astoria in Orlando on November 16th.

Renishaw Introduces 3D Printed Styli

This month, Renishaw introduced a 3D printed stylus version to its already wide range of available styli. The company uses its metal powder bed fusion technology to provide customers with complex, turnkey styli solutions in-house, with the ability to access part features that other styli can’t reach. 3D printing helps to decrease the lead time for custom styli, and can manufacture strong but lightweight titanium styli with complex structures and shapes. Female titanium threads (M2/M3/M4/M5) can be added to fit any additional stylus from Renishaw’s range, and adding a curved 3D printed stylus to its REVO 5-axis inspection system provides flexibility when accessing a component’s critical features. Components with larger features need a larger stylus tip, which Renishaw can now provide in a 3D printed version.

“For precision metrology, there is no substitute for touching the critical features of a component to gather precise surface data,” Renishaw wrote. “Complex parts often demand custom styli to inspect difficult-to-access features. AM styli can access features of parts that other styli cannot reach, providing a flexible, high-performance solution to complex inspection challenges.”

Digital Construction Grant Competition

Recently, a competition opened up in the UK for organizations in need of funding to help increase productivity, performance, and quality in the construction sector. As part of UK Research and Innovation, the organization Innovate UK – a fan of 3D printing – will invest up to £12.5 million on innovative projects meant to help improve and transform construction in the UK. Projects must be led by a for-profit business in the UK, begin this December and end up December of 2020, and address the objectives of the Industrial Strategy Challenge Fund on Transforming Construction. The competition is looking specifically for projects that can improve the construction lifecycle’s three main stages:

Designing and managing buildings through digitally-enabled performance management
Constructing quality buildings using a manufacturing approach
Powering buildings with active energy components and improving build quality

Projects that demonstrate scalable solutions and cross-sector collaboration will be prioritized, and results should lead to a more streamlined process that decreases delays, saves on costs, and improves outputs, productivity, and collaborations. The competition closes at noon on Wednesday, September 19. You can find more information here.

Click Bioprinting Research

Researcher Janarthanan Gopinathan with the Seoul University of Science Technology (Seoul Tech) published a study about click chemistry, which can be used to create multifunctional hydrogel biomaterials for bioprinting ink and tissue engineering applications. These materials can form 3D printable hydrogels that are able to retain live cells, even under a swollen state, without losing their mechanical integrity. In the paper, titled “Click Chemistry-Based Injectable Hydrogels and Bioprinting Inks for Tissue Engineering Applications,” Gopinathan says that regenerative medicine and tissue engineering applications need biomaterials that can be quickly and easily reproduced, are able to generate complex 3D structures that mimic native tissue, and be biodegradable and biocompatible.

“In this review, we present the recent developments of in situ hydrogel in the field of click chemistry reported for the tissue engineering and 3D bioinks applications, by mainly covering the diverse types of click chemistry methods such as Diels–Alder reaction, strain-promoted azide-alkyne cycloaddition reactions, thiol-ene reactions, oxime reactions and other interrelated reactions, excluding enzyme-based reactions,” the paper states.

“Interestingly, the emergence of click chemistry reactions in bioink synthesis for 3D bioprinting have shown the massive potential of these reaction methods in creating 3D tissue constructs. However, the limitations and challenges involved in the click chemistry reactions should be analyzed and bettered to be applied to tissue engineering and 3D bioinks. The future scope of these materials is promising, including their applications in in situ 3D bioprinting for tissue or organ regeneration.”

Analysis of Solidification Patterns and Microstructural Developments for Al10SiMg Alloy

a) Secondary SEM surface shot of Al10SiMg powder starting stock, (b) optical micrograph and (c) high-magnification secondary SEM image of the cross-sectional view of the internal microstructure with the corresponding inset shown in (ci); (d) the printed sample and schematic representation of scanning strategy; The bi-directional scan vectors in Layer n+1 are rotated by 67° counter clockwise with respect to those at Layer n.

A group of researchers from Queen’s University and McGill University, both in Canada, explain the complex solidification pattern that occurs during laser powder bed fusion 3D printing of the Al10SiMg alloy in a new paper, titled “Solidification pattern, microstructure and texture development in Laser Powder Bed Fusion (LPBF) of Al10SiMg alloy.”

The paper also characterizes the evolution of the α-Al cellular network, grain structure and texture development, and brought to light many interesting facts, including that the grains’ orientation will align with that of the α-Al cells.

The abstract reads, “A comprehensive analysis of solidification patterns and microstructural development is presented for an Al10SiMg sample produced by Laser Powder Bed Fusion (LPBF). Utilizing a novel scanning strategy that involves counter-clockwise rotation of the scan vector by 67° upon completion of each layer, a relatively randomized cusp-like pattern of protruding/overlapping scan tracks has been produced along the build direction. We show that such a distribution of scan tracks, as well as enhancing densification during LPBF, reduces the overall crystallographic texture in the sample, as opposed to those normally achieved by commonly-used bidirectional or island-based scanning regimes with 90° rotation. It is shown that, under directional solidification conditions present in LPBF, the grain structure is strictly columnar throughout the sample and that the grains’ orientation aligns well with that of the α-Al cells. The size evolution of cells and grains within the melt pools, however, is shown to follow opposite patterns. The cells’/grains’ size distribution and texture in the sample are explained via use of analytical models of cellular solidification as well as the overall heat flow direction and local solidification conditions in relation to the LPBF processing conditions. Such a knowledge of the mechanisms upon which microstructural features evolve throughout a complex solidification process is critical for process optimization and control of mechanical properties in LPBF.”

Co-authors include Hong Qin, Vahid Fallah, Qingshan Dong, Mathieu Brochu, Mark R. Daymond, and Mark Gallerneault.

3D Printed Titanium Thomas Edison Statue

Thomas Edison statue, stacked and time lapse build

Oskar Zielinski, a research and development technician at Arcam EBM, a GE Additive company, is responsible for maintaining, repairing, and modifying the company’s electron beam melting (EBM) 3D printers. Zielinski decided that he wanted to test out the Arcam EBM Q20plus 3D printer, but not with just any old benchmark test. Instead, he decided to create and 3D print a titanium (Ti64) statue of Thomas Edison, the founder of GE. He created 25 pieces and different free-floating net structures inside each of the layers, in order to test out the 3D printer’s capabilities. All 4,300 of the statue’s 90-micron layers were 3D printed in one build over a total of 90 hours, with just minimal support between the slices’ outer skins.

The statue stands 387 mm tall, and its interior net structures show off the kind of complicated filigree work that EBM 3D printing is capable of producing. In addition, Zielinski also captured a time lapse, using an Arcam LayerQam, from inside the 3D printer of the statue being printed.

“I am really happy with the result; this final piece is huge,” Zielinski said. “I keep wondering though what Thomas Edison would have thought if someone would have told him during the 19th century about the technology that exists today.”

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Category: Electron Beam Melting (EBM)