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19 February 2019 18:05
Metal 3D Printing: Where are We Today?
Just a decade ago, few believed that metal 3D printing could ever be a serious contender for serial production. However, the technology has seen a rapid evolution, particularly over the last few years. Now, with metal parts being used in applications as wide-reaching as medical, automotive and aerospace, the technology is gearing up for production.
But where are we today?
As the metal 3D printing market continues to grow, it’s important to keep up with the ever-changing landscape. That’s why today, we’ll be taking a look at the evolution of metal 3D printing – how far the technology has come, where things currently lie and what the future holds for this innovative technology.
Key events that have shaped metal 3D printing
Since the 1980s, the technological and market landscape has evolved significantly for metal 3D printing. While the growth of the technology in the early 2000s was incremental, the landscape has changed over the last five years, with a number of new players entering the market.
Metal AM systems have evolved to a point where they are now able to process more materials and enable a wider range of applications.
A brief overview of some of the key events to shape the evolution of the technology:
- 1980s: Dr Carl Deckard (University of Texas) patents a selective laser sintering technology for plastics. This invention will pave the way for metal 3D printing.
- 1988: Dr Ely Sachs (MIT) develops a new binder jetting process that would become the basis of metal binder jetting. Metal Binder Jetting would subsequently be licensed to ExOne in 1996.
- 1994: EOS unveils its prototype EOSINT M160 machine, based on metal laser sintering technology. The following year, the company launches the EOSINT M250 machine, which is the first to use metal laser sintering technology.
- 1995: The Fraunhofer Institute in Aachen, Germany, files the first patent for the laser melting of metals.
- 1998: Optomec commercialises its Laser-Engineered Net Shaping (LENS) metal powder system, one of the Direct Energy Deposition technologies.
- 2000: Electron Beam Melting (EBM) technology is patented and licensed by Arcam AB.
- 2002: Arkham launches the first EBM machine, the S12.
- 2004-2005: EOS switches from the CO2 laser used in plastics SLS to a fibre laser that is more suitable for melting metals.
- 2017: US-based startup, Digital Alloys, announces its patented Joule method for metal 3D printing and closes a $12.9 million Series B funding round the following year.
- 2018: Following its success with its Multi Jet Fusion system for polymers, HP throws its hat into the metal 3D printing ring with the debut of its Metal Jet 3D printing system for metals. The same year, the Wohler’s Report announces an 80% growth in metal AM systems for 2017.
- 2019: Desktop Metal, which offers its Production and Studio metal AM systems, closes $160 million in a Series E investment round.
The evolution of metal AM systems
DMLS — the starting point
The origins of direct metal 3D printing can be traced back to 1994, when EOS first introduced its EOSINT M250 machine. This machine was based on direct metal laser sintering (DMLS) technology.
At the time, the DMLS sintering process worked similarly to Selective Laser Sintering for plastics, in that metal powder was partially melted and fused together to create metal parts.
However, sintering isn’t the most efficient way to form fully dense metal parts.
Between 2004 and 2005, EOS introduced more powerful fibre lasers to its machines — and this changed the game significantly.
Now, although the term DMLS retains the legacy of sintering, modern DMLS machines are able to fully melt metal powders, delivering parts with a density of over 99%.
As of 2019, DMLS and EBM remain the two most widely used metal additive manufacturing processes.
Thanks to ongoing technological improvements and increased competition in the metal 3D printing market, metal AM systems are becoming increasingly more optimised for production.
The last several years have been particularly exciting as new production concepts for metal 3D printing have emerged.
Key players like EOS, Concept Laser and 3D Systems have all recently launched solutions reflecting their respective visions of metal 3D printing as a part of a smart factory.
The majority of these solutions share similar characteristics: they are modular, configurable and offer a high level of automation in a bid to maximise efficiency and reduce the amount of manual labour required.
With the industry moving towards greater automation and flexibility, these modular platforms can provide manufacturers with a means to integrate the technology more easily into their production processes and scale up faster.
The metal 3D printing market is a growing area of activity, with over 20 companies producing metal AM systems. The number of new players entering the market is growing continuously, as companies seek to lead the drive towards series production.
Digital Alloys and Joule Printing
One example is Digital Alloys, which has developed its proprietary Joule printing technology, designed to tackle the problems of speed and cost.
Joule printing uses metal in wire form, which is typically cheaper than metal powders. The high-speed process is controlled through a closed-loop system, with the metal wire fed into a precision motion system.
The technology, which is due to be commercially released in 2020, promises greater process reliability, faster speeds and low raw material costs. These factors combined could help to significantly reduce overall production costs.
HP’s Metal Jet
HP first burst onto the 3D printing scene with its Multi Jet Fusion technology, used for plastics. In 2018, the company made its first foray into the metal 3D printing arena with its Metal Jet system.
The system is based on HP’s binder jetting technology, using off-the-shelf metal injection moulding (MIM) powders to bring down costs. The system, also slated for a 2020 release, is said to be 50 times faster than comparable binder jetting or selective laser melting systems.
Founded in 2015, the US-based company was co-founded by Ely Sachs, the inventor of the binder jetting process.
With a goal to make metal 3D printing as accessible as possible, Desktop Metal offers its Studio System, targeted at small production runs, as well as its Production System, aimed for large-scale 3D printing.
Desktop Metal is now one of a handful of 3D printing startups that have reached unicorn status, valued at around $1.2 billion.
The flurry of activity within the metal 3D printing space is yet another positive sign of the technology moving forward towards the dream of serial AM production.
Direct Energy Deposition (DED)
Another technology that is bringing exciting developments into the world of metal 3D printing is Direct Energy Deposition (DED).
Originating from welding processes, DED technology uses a laser beam to melt metal powders or wire as they are pushed through a nozzle onto a build platform. Unlike binder jetting and powder bed processes, this technology is particularly suitable for creating larger components.
Historically, DED has been used to repair components by adding features to an existing part. Now it’s more widely for manufacturing in industries ranging from aerospace & defence to oil & gas.
Norwegian company Norsk Titanium, for example, uses its proprietary DED technology (Rapid Plasma Deposition) to produce FAA-approved aircraft titanium parts for Boeing 787 Dreamliner.
Taking a hybrid approach
A key development being driven by DED technology is hybrid manufacturing.
In this type of manufacturing process, DED can be combined with a subtractive process such as milling, to manufacture and finish parts within a single system.
For many industries, this approach could significantly streamline the manufacturing process. The benefit is clear: instead of 3D printing a part and moving it to a different piece of equipment for finishing, the entire operation can take place in a single machine. This process reduces the time needed to produce and post-process each part.
There a now a small number of companies offering hybrid solutions, including Hybrid Manufacturing Technologies and Imperial Machine & Tool Co.
Similarly, several manufacturers of cutting machine tools and CNC mills, like DMG Mori and Mazak, now offer some form of AM capability.
Hybrid hardware solutions do remain limited, due to the early stage of the technology. That said, the harnessing additive and subtractive operations in one system has the potential to transform the way parts are manufactured.
Developments in materials for metal 3D printing
Achieving material diversity
Developing metals for additive manufacturing is a challenging process — developing a completely new metal alloy could take up to 3 years.
Early users of metal 3D printing sourced metal powders from casting and forging markets. These, however, aren’t the ideal choice for additive manufacturing, where specific chemistries and microstructures are required.
As the technology has evolved, material developers and early adopters, more familiar with the technologies and machines, have begun to develop metal materials that are suitable for AM.
As metal 3D printing looks towards series production, material diversity will play an increasingly greater role. The more quality materials that are available, the broader the scope of applications for the technology.
3D printing challenging metals
The development of powerful lasers within DMLS systems has meant that more materials can be processed with the technology. These include metals such as stainless steel, titanium, cobalt chrome and Inconel alloys.
However, not all metals lend themselves to 3D printing easily. For example, copper and precious metals are particularly challenging to print, in part because they reflect the heat applied by a laser beam.
Fortunately, there have been moves to develop new systems capable of 3D printing such metals.
At formnext 2018, TRUMPF demonstrated its green laser technology which can print pure copper as well as other precious metals.
The company believes that 3D printing pure copper can become an alternative way to create conductive inductors and heat exchangers, which are particularly useful for the electronics and automotive industries.
Similarly, Electron Beam Melting (EBM), a process that uses an electron beam as the heat source, has been developed to handle high-heat and crack-prone materials, like titanium aluminide (TiAl).
Thanks to its unique ability to reach extremely high temperatures, EBM is reportedly the only commercial AM solution for manufacturing titanium aluminide parts.
Materials suppliers move to metal AM
In spite of the challenges involved in developing metal powders and alloys suitable for 3D printing, the list of manufacturing materials suppliers looking to join the market is steadily increasing.
Companies like Carpenter Technology, Sandvik AB, voestalpine and Höganäs AB are just some of the well-known names that have identified metal 3D printing as a high-value, long-term opportunity.
Over the last two years, the industry has seen these companies making investments in AM, consolidating their presence in the metal powder market.
In February 2018, Sandvik, a leading supplier of metal powders, announced a $25 million investment into the construction of a metal powder production plant in Sweden. The new plant facility will be producing nickel and titanium alloys.
Carpenter Technology has also been increasing its activities in metal AM, with a series of investments into companies like CalRAM, an AM service company, and Puris, a maker of titanium powders.
In 2018, the company acquired LPW Technology, a leading provider of metal powders for DED and Powder Bed Fusion technologies.
As a key player in the development of metal materials for AM, LPW Technology is undoubtedly a significant addition to Carpenter’s portfolio, establishing the company’s firm entry into the materials market.
With other materials companies also taking steps to respond to the growth of the metal 3D printing market, the industry can expect to see significant developments in the diversity and performance of new metal alloys over the coming years.
Is the cost of materials coming down?
The cost of metal powders of AM has been significantly higher than the cost of metals for traditional processes.
“Material price is another crucial factor [for AM end-part production]: the materials are very costly and manufacturing is all about cost,” says HP’s Tim Weber, speaking to AMFG in a recent interview.
“If you have a production method that provides a way to produce parts at a lower cost, most manufacturers will make the switch right away. But we need to make sure that the overall material costs are reduced.”
For example, the cost for TI64 powder can range from $150 to $400 per kilogram. These powders require a lot of energy to be produced and must be of certain size and form, while maintaining a high level of purity. These factors contribute to the high costs.
However, with the entry of new players into the materials market, this increased competition will likely see the price of metal powders continue to fall.
One way to reduce material costs could be to use cheaper metal injection moulding (MIM) powders.
Several equipment manufacturers, like HP, Desktop Metal and Digital Metal have jumped at this opportunity, developing jetting systems suitable for processing MIM powders.
Using low-cost MIM powders not only makes the technology more accessible, but also significantly expands the material choice for metal AM.
Developments in software for metal 3D printing
Another growing, yet often less talked about, area of metal 3D printing is simulation software.
The nature of the metal 3D printing process means that it can be difficult to achieve a successful print the first time around. The complexity of the geometries, coupled with the high temperatures and support structures required are just some of the challenges facing engineers designing for metal 3D printing.
Metal simulation software is, therefore, a critical element in the printing process. With simulation, engineers are able to predict and analyse how a part will behave during the process before the part actually goes to print. Users can optimise their build preparation, thereby reducing the chances of print failure.
There is a growing number of simulation software solutions on the market, including Autodesk’s Netfabb, Dassault Systèmes’ SIMULIA and Simufact.
Interestingly, as is the case with materials, several established players are also eyeing AM as a key opportunity.
Let’s take ANSYS as an example. ANSYS is a well-known provider of engineering simulation software, typically used to design products and semiconductors in addition to simulation solutions that can test product performance.
ANSYS made its entry into the metal 3D printing market with its acquisition of 3DSIM, a metal simulation company in 2017. Since then, the company has gone on to release its Additive Suite and Additive Print simulations platforms in early 2018.
The challenges of metal 3D printing
Standardising metal parts
Making the shift from prototyping to production is not without its challenges. Series production, in particular, is based on a specific set of regulations, documentation, and processes that have become established norms.
Metal 3D printing is just at the start of its journey towards establishing its own standards. Currently, standards exist primarily to describe the general characteristics of metal 3D printing processes like DED and Powder Bed Fusion.
Some material specifications are also being developed, including standards for titanium, nickel alloys, stainless steel, cobalt chromium.
Notably, the Metal Powder Industries Federation (MPIF) has recently issued nine MPIF Standard Test Methods for characterising metal AM powders.
Aimed at designers, manufacturers and users of metal AM parts, this collection is yet another sign of industries recognising the growing role of metal 3D printing in the manufacturing world.
Cost and speed
In spite of the impressive progress made, metal 3D printing is still plagued by two key limitations: cost and speed.
“There simply aren’t many good options today if you want to use 3D printing for production. This is because systems are too slow, production costs are too high and the processes are too complex”, says Digital Alloys’ CEO, Duncan McCallum.
For instance, the average cost of a powder-bed metal system can range from anywhere between $200,000 and $2 million. Of course, this excludes the cost of materials and any post-processing steps that will need to be taken.
As metal AM continues to gain traction as a manufacturing solution, the technology will need to become faster and cheaper to further accelerate adoption.
Because of its suitability for high-value, low-volume applications, metal 3D printing was adopted early on by the aerospace and medical industries.
However, the potential of metal 3D printing for manufacturing makes it an exciting technology for industries outside of these well-known applications.
That said, increasing production volumes remains a key hurdle for wider AM adoption. This is particularly the case for the automotive industry which, apart from the performance racing and luxury vehicle sectors, typically require high production volumes.
“[Automotive] production volumes are considerably different from the volumes of aerospace or medical,” says Harold Sears, Ford Motor Company’s Technical Leader for Additive Manufacturing. “So we have to look at systems that are capable of producing parts in minutes or seconds as opposed to days and hours. Anything that we can do to push the technology into faster build speeds is definitely what will help us as well”.
While advancements in hardware will help to drive production volumes further, process optimisation is another way to achieve higher volumes with metal 3D printing.
Betatype has demonstrated this with the creation of heatsinks for LED automotive headlights.
Through design optimisation, the company has been able to develop a way to stack many parts together in one building envelope.
This approach has made it possible to manufacture 384 parts at once, reducing the build time from 444 hours to less than 30 hours and the cost from $39 down to just $3.
Betatype believes that running just 7 machines with this optimised process could achieve 1 million parts per year, approaching the automotive industry’s requirements in terms of both volume and cost-effectiveness.
The Future of Metal 3D Printing
Metal 3D printing has made great strides, overcoming the 3D printing hype of the mid-2000s. Today, we’re seeing advancements in every area of the market, from the development of new printing processes to faster machines and a greater range of suitable materials.
On the investment side, the market is growing rapidly, as larger companies invest in and acquire specialist companies and new players enter the market. Just recently, printing giant Xerox made a clear move into metal 3D printing with the acquisition of metal 3D printing startup, Vader.
With the landscape changing rapidly, what will the situation be in 10 years? While difficult to predict, one thing is clear: metal 3D printing is well on its way towards becoming a truly viable manufacturing solution.