E1: Questions and answers

How fast is this industry segment growing?
According to SmarTech the industry segment is growing by more than 20% annually.

How large will this segment be relative to today in 5 years? 10 years?

Of course that’s difficult to predict in detail, but in a general sense it can be said that the use and growth of AM within the medical sector will definitely play an increasingly important part going forward, as the need for medical implants and prostheses will continue to grow – as will the industrialization and optimization of AM.

What is the main purpose of this? What are you going to do with this in the medical field?
We will provide powder for- and produce implants that offer optimized and tailor-made designs for unique and life-changing medical components.

What are the gaps that exist in understanding titanium for medical applications?
Titanium is widely used in certain medical applications such as hip and dental implants, where the material is proven, and additive manufacturing is the best method to use. Before a material is approved for implants it has of course been through extensive regulatory approval processes.

Are you making hips in your English subsidiary still?
No, the facility in England was divested – so we are no longer manufacturing hips ourselves.

What is the benefit of producing medical parts by 3D printing, compared to machining?

Using AM contributes to a larger freedom of design, making it possible to design parts that cannot be manufactured by other processes available today. It is also a matter of making these customized solutions available on a larger scale, meaning it will ultimately be more cost-efficient. For some implants such as HIP cups, the specific structure that is printed has a positive effect on bone ingrowth.

Which type of equipment is needed on your materials to 3D print for the medical industry?
This depends on a variety of parameters such as the printer machine/technology, the powder characteristics, material, printing parameters, and what criteria you as a customer have in terms of tolerance, surface finish, etc. The medical industry also has several standards that need to be fulfilled – such as the ISO 13485 medical certification, which we are proud to say we have achieved. To summarize, it always comes down to a close collaboration between Sandvik and each customer to decide on the criteria, case by case.

I want to know more about the use of 3D printing in joints supplements for medical use.
The use of 3D printing for medical implants allow for the production of porous materials, which increases the rate of bone ingrowth within the body.

How does additive manufacturing apply to prosthetic surgery?
There are already many medical implants and components produced through additive manufacturing today. Each medical application is unique, why it needs to be looked into case by case. Some of these were highlighted in the first episode of our webinar series Additive By Sandvik: Material Matters, focusing on this topic. If you missed the livestream, a recorded version of the session is now available here.

What type of additive manufacturing technique is being used here in this webinar session? Is it Selective Laser Melting in Powder Bed Fusion?
All examples in the webinar depicts PBF-LB processing.

Do you consider that MDR2017 / 745 sufficiently covers the regulation of these new production processes through additive manufacturing?
We consider it a good baseline to regulate any manufacturing of products for the medical industry.

Do you use any ultrasound technique in the printing process, in order to control microstructure (grain morphology and texture mitigation)?
No, not currently.

What kind of surface modification techniques does Sandvik employ for the additively manufactured implants?
Generally, it can be said that it depends on the requirement on the end-application. Two examples are mild blasting and shot peening.

I’d like to know more about post treatment of 3D printed titanium medical segments.
Post treatments are usually limited to stress relief and solution annealing heat treatments. When a complete elimination of porosity is needed, hot isostatic pressing can also be applied.

Will the 3D printed medical parts need any metal cutting/machining to be within the dimensional tolerances?
It depends on the application. In some parts the surfaces that are in contact and experience a movement, such as the ball and the cup in a hip joint, need machining to get the right surface finish and tolerances.

Do implants manufactured in the printing process need finishing?
It depends on the desired surface finish of the implant. Some implants, or certain details in an implant might require machining, whereas for others a somewhat rougher surface profile is actually beneficial.

What is the probability of orthopedic implants being manufactured successfully using Binder Jetting?
This is a bit tricky to predict. Since Binder Jet technology today is being processed without shielding gas, you can´t use any reactive metals – such as titanium and aluminum – without risk of fire and/or explosion, even though some of the providers of binder jetting technology seem to have a solution for this. Many implants today are made from Titanium 64. However, it is of course possible to produce orthopedic implants from other materials, such as CoCr, and develop designated printing and design parameters for Binder Jetting.

Is titanium the only metal used inside the body to enhance bone regrowth?

As of today, yes.

Does titanium have properties similar to that of bones?
Yes, titanium has a Young’s modulus similar to bones and is also biocompatible - meaning the bone/human body will not reject the titanium implant.

I’d like to know more about quality assurance from raw material purchase until implantable product, considering the defects which are inherent for the different process steps.
The composition control and the level of residual elements are usually originated from the raw material, so when choosing the rods for powder atomization, one must ensure that these are well controlled since they can be produced from scrap material and/or Ti sponges. Since we source our titanium internally, we are in full control throughout the entire process chain.

Which type of equipment is needed on your materials to 3D print for the medical industry?
This depends on a variety of parameters such as the printer machine/technology, the powder characteristics, material, printing parameters, and what criteria you as a customer have in terms of tolerance, surface finish, etc. The medical industry also has several standards that need to be fulfilled – such as the ISO 13485 medical certification, which we are proud to say we have achieved. To summarize, it always comes down to a close collaboration between Sandvik and each customer to decide on the criteria, case by case.

Will the titanium powders be available for purchase at a practical expense of both financial and temporal (in terms of delivery) and real world marketability? I.e., will the medical field require enough surgical and other utensils to warrant interest in this field?
Yes, we believe it will. Without saying too much, we can reveal that there are some Ti powder volumes going into the market today – likely motivated by a good turn around. We also know that the demand for additively manufactured medical implants, prostheses and other devices in titanium is expected to grow. Total shipments of Titanium powder for additive manufacturing exceeded 400 Metric Tons in 2019 according to the SmarTech 2020 report.

What about the degradation of Ti in the human body?
The typical life cycle of Ti in the human body stretches across some 20 years. In theory, the use of additive manufacturing would not affect this, as the composition control is just as strict. However, mechanical wear inside the body could lead to degradation, also influenced by the type of implant and its design. This is however valid for any implant material used.

How close are you to manufacturing dental implants made of titanium, using additive manufacturing? What grade of titanium would that be?
As a matter of fact, this is already realized. There are currently producers using the Ti powders for dental applications, so this is readily available on the market.

Compared to surgical implants, what grade of Ti is required for application in pharmaceutical products such as excipients?
As we supply fully alloyed gas atomized metal powders to the market and are not currently in the business of excipients, we regrettably can’t answer that.

I studied hip replacements in Biomaterial in Saarbücken and they alloyed the Ti with Vanadium to get lower elongation to grow faster in the bone. Is this still applicable?
The elongation of implants is aimed to match that of human bones. Addition of different elements can be used to reach that objective. In the normal Ti grade 23 we add Aluminum and Vanadium to the composition.

Who is the major supplier of titanium for Sandvik?

Sandvik, actually. We source the feedstock internally.

How are these powders produced?
Our Osprey® titanium powder is produced via Electrode Induction Melting Inert Gas Atomization (EIGA) process.

What type of inert gas does Sandvik use when atomizing the titanium powder?
We use argon gas for the atomization of our Osprey® titanium powder.

How does Additive Manufacturing apply to the manufacturing process of titanium and its alloys?
Ti and its alloys have a good synergy with additive manufacturing. Through good process control it’s possible to obtain properties that are better than those observed when manufacturing traditionally (i.e., cast, wrought...).

What is the advantage of Osprey® powders compared to the competitor’s titanium powders?
The benefit of using Osprey® metal powders is that we control the entire processing chain – from Ti sponge to finished powder – allowing for excellent traceability and quality control.

Is it possible to use other titanium based powders?
Yes. We are always looking to widen our product portfolio with new alloys.

Is the Sandvik R&D team working on new titanium alloys with lower Young modulus?
Currently, Sandvik is offering the Ti64 grade 5 and grade 23 to the market. However, we are always open to looking into more alloys upon request.

You can see some satellites at the SEM picture. How does this affect flowability?
Too many satellites affect the flowability negatively – but we are proud to say all Osprey® metal powders offered today has good flowability.

We could see some satellites on the powders in the micrographs given. How are they influencing the final properties of the implants, in the regards of surface finish?
The most important factor to quality assure the surface finishes of implants is to have a well-defined process parameter window in the powder bed fusion laser beam process. With the powder we offer, this is possible.

What is the corrosion resistance of additively manufactured titanium, compared to wrought titanium?
Sandvik has not yet investigated corrosion resistance of our own Titanium in any environment. The corrosion resistance depends on many aspects such as the corrosive media, the surface roughness and microstructure. This is also influenced by the printing method used and subsequent heat treatment procedure and finishing.

I’d like to know more about the impact of moisture in titanium powders.
Moisture impairs the ability of the powder to spread on the substrate during printing, and can also cause particle agglomeration.

What is known about the where and how titanium powder picks up moisture during additive manufacturing? This is a question that needs focus on moisture interactions with the powder surface and not just environmental conditions.
In general, Titanium powder absorbs moist quickly, and need careful attention during handling. For our Titanium products, we keep control of the moisture by having the process under protective atmosphere during all production steps, including packaging. Moisture can later be picked up during powder handling – like when a can is opened for use.

Since titanium has a high affinity for oxygen, what is the oxide thickness and what is the critical thickness for the sintering process to work?
In the case of powder bed fusion, the titanium powder particles are fully melted - so there is no sintering process occurring. This renders the oxide scale thickness less crucial for the behavior in the powder bed fusion laser beam process.

Did you consider preparation of powders based on Ti-Ta and Ti-Mo?
We have considered these compositions, but are focusing on Ti64 grades for now.

Do you have gamma TiAl grader powder?
No, not yet. If you are interested to discuss future potential, and/or if you have any specific demands you are more than welcome to contact us by making an enquiry on our website.

I did my master thesis on the Osprey® process on duplex stainless steels in Sandviken, 1980. How does the process work for titanium?
Interesting! We are currently not using the Osprey® process for titanium alloys.

How can I learn more about Ti6Al4V powder technology?
Please visit the titanium product page on our website, or get in touch with one of our metal powder experts!

Do you have plans to produce magnesium alloys for additive manufacturing?
Not as of today.

How many countries are Sandvik currently supplying their products to?
We supply our Osprey® products to all continents globally.

Is there any gas used for cooling?
Gas is used both to disintegrate the melt stream into droplets during atomization, and to cool the droplets so they solidify into powder particles.

Does Sandvik currently recycle their inert gas used in atomizing and 3D printing?
Not currently – but we are however looking into various solutions allowing for us to do so, within the near future.

Who should I contact for supply of 6/4 ELI bar as feeder stock for your atomizer?
We welcome you to submit an enquiry through our website!

I’m interested in designing alloys of beta titanium.
We are always open to discuss new products and solutions with our customers. Please contact one of our metal powder experts here.

Is it possible to buy powders?
Of course! Please send in your RFQ via our website and we will get in touch with you shortly.

How you see the future in terms of utilizing quantum computers?
This is an interesting question. Of course, artificial intelligence will support our future development, and we except quantum computers and similar digital support to be part of this. To which extent, however, remains to be seen.

I’m interested in knowing more about aerospace applications.
Our additive manufacturing center and Osprey® powder plants in Sandviken, Sweden and Neath, UK, are AS9100:D certified for use in the aerospace industry – and we do deliver to the segment. We’re also planning to produce a live session focusing specifically on this topic. In the meantime, you are more than welcome to contact us with any questions you might have.

What types of metals and alloys can you print with?

There’s a broad range of materials that can be manufactured through AM, including nickel, titanium, steels, and many others. We welcome you to visit our website to learn more, or get in touch with one of our leading experts in metal powders or additive manufacturing!

Which alloys do you use?
We supply the major part of the available powder alloys for AM. This includes alloys that are Fe-based, Ni-based, Co-based, Al-based, Cu-based – and more.

How far have we come with 3D printing of super alloys?
Globally there are some applications that are used, the major part in non-rotating applications. There are still a lot of developmental activities ongoing to implement more super alloy-based applications produced via AM.

Overall part dimensions that can be achieved by 3D printing?
It depends on the equipment used; here are several options on the market. Sizes range from a few millimeters, to typically several centimeters. For laser printing, normally an envelope of 400x400x400 mm is used but larger equipment is available.

What minimum cell size is possible to print for open cell like structures?
If you are referring to the smallest lattice structure that is possible to attain, it depends on the AM technology, machine, material, developed parameters, component design, customer criteria, printing parameters, and the empty space needed to allow for the loose powder to escape. To state an example, it’s not uncommon to print lattice structures with empty spaces measuring a few tenths of a millimeter.

How about the gas used for the 3D printing operations?
Normally argon or nitrogen is used in powder bed fusion laser, as the protective atmosphere.

What about laser power and laser types regarding process using it (SLM, LMD, LMWD, LMPD)?
Typically laser power is maximum 400 W, but this is modified as a part of the print parameter settings used, where scan speed, hatch distance and laser power are some of the parameters settings. Yb-fiber lasers are common in additive manufacturing but in some applications such as printing Copper, other laser sources may have to be used.

Where should we use these kind of powder additives in the field of mining?
There are plenty of parameters to consider when finding an application that can be motivated to manufacture additively. We have gathered some information on the matter on our website, and in addition, you are always welcome to get in touch with us directly for support and advice when it comes to implementing AM into your offering.

What are the risks that we have to consider when working with metal powder in AM?
The most prominent risk when working with titanium powders is the risk for explosion, due to the materials’ inherent reactivity.

Does Sandvik currently recycle their inert gas used in atomizing and 3D printing?
Not as of today – but we are however looking into various solutions allowing for us to do so, within the near future.

Can these additive materials be used on HP 3D printing machines? Or, do you recommend any other manufacturing company?
Yes, several of our powders can be used on a HP machine. We manufacture and tailor our metal powders according to your specific needs and specification. Materials such as Titanium and Aluminum are generally more difficult to print using Binder Jetting Technology, but there are some of the providers of the technology that have the ability to print Titanium.

Are there any plans of diversifying into 3D printing of Tungsten Carbide components?
Yes. As a matter of fact, we are currently developing additive manufacturing processes for cemented carbide. Please send us an enquiry if you are interested in learning more.

Are you interested in cooperation on powder testing using SLM and SLS processes?
We are always open for interesting suggestions and cooperation’s regarding material development. Please get in touch and we'll be happy to discuss.

Can we print with gold instead of steel?
It is possible, but for known reasons very expensive.

Are you manufacturing in India?
The AM division does not currently manufacture anything in India. Other parts of Sandvik, however, do.

I’m interested in applications of Hafnium through Additive Manufacturing.
Hafnium is used mostly as an alloying element for controlling microstructure and materials properties. We have no experience of printing in Hafnium alloys or pure Hafnium.

How you see the future in terms of utilizing quantum computers?
This is an interesting question. Of course, artificial intelligence will support our future development, and we except quantum computers and similar digital support to be part of this. To which extent, however, remains to be seen.

How long it takes from powder idea to test series of spherical powder for AM?

From a few months to years – all depending on the complexity of the idea and the powder composition.

Where do you test the powders?
The powders are tested in-house in our production units, to ensure a robust and reliable quality. As a next step, our customers and partners perform their own quality testing.

Are there any standards upcoming for powder type, particle size, microstructure obtention, and heat treatment?
Some standards and guidelines exist, and some are under development. We recommend looking into the development of standards via ASTM F42 or ISO Technical committee 261.

Have you quantified process impact on part obtained (mechanical, physical properties, fatigue...)?
The physical and mechanical properties of our powders and AM capabilities for each of these are published on our website.

If applicable, I’d like to know what agent can compromise the strength or potency of the powder?
When it comes to titanium powders, one agent that can compromise the strength and potency is high oxygen content. Our Osprey® powders are atomized and packed in a completely protected and designated environment, to prevent this from being an issue.

How do you improve wear resistance?
Wear resistance is in general related to an alloy and its properties, such as hardness. For better wear resistance, the right material should be picked for the specific application. Surface hardening can also be used for better wear properties.

How accurate can 3D printed medical parts be?

There’s no generic answer to this question, as it depends on a variety of different aspects – such as the printer machine/technology, the powder characteristics, material, printing parameters, and what criteria you as a customer have regarding tolerances, surface finish, etc.

I’d like to know a bit more about accuracy in additive manufacturing.
The accuracy of a printed part depends on the print method used as well as the particle size distribution of the metal powder. Distortion can occur during printing, due to thermal stress or poor design, and too few support structures in the print. Heat treatment is needed to stress relieve the material, and for tighter tolerances machining is often necessary.

What aspects should one take into account in the manufacturing of products in an additive process, to verify their quality?
This is very much depending on the industry segment in which the products will be used. Usually, there are standards that regulate the properties to fulfill, and Sandvik recommends following these.

Which methods/processes (NDE) to you use to assess the build quality?
We utilize several methods and processes but to state an example, we use Archimedes to measure density and, when higher precision is needed, we also use CT scanning.

Have you quantified process impact on part obtained (mechanical, physical properties, fatigue...)?
The physical and mechanical properties of our powder and AM capabilities for each of these are published on our website.

Curious about metal 3D printing metallurgical property flaws. Specifically non-grain oriented structures and non-uniform melt deposition causing more chances of failure.
This is nothing we have observed. Our belief and experience tells us that the right AM process, followed by the proper heat treatment to ensure the metallurgy of the printed part, enables an equal or better result than conventionally produced parts.

How is the surface of 3D printed parts enhanced?
Surfaces can be improved by optimization of processing parameters which, when properly applied, can significantly reduce surface roughness. Post processing such as electrochemical methods, blasting and machining can be used when better surfaces are needed.

What about position of the part on substrate regarding machining processing?
The position of the part on the substrate doesn’t seem to be significant, according to recent studies and evaluations.

On a product made on M290, what is the impact of repairs on its microstructure and subsequent mechanical properties post repairs?
Assuming that the product in question is produced on an EOS M290 platform, the microstructure depends on the material as well as the print parameters. The mechanical properties can be fine-tuned with the right kind of heat treatment once the build is done.

Could you tell me a bit more about material microstructure in AM?
Microstructure of AM parts can vary significantly between different materials. Overall, due to fast solidification of AM, fine grains and segregation can be expected. Heat treatment procedures are important to arrive at a desired microstructure with desired material properties.