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    Additive Manufacturing

    Are materials the next challenge for additive manufacturing?

    • By MTDCNC
    • March 23, 2021
    • 9 minute read

    Having been entrenched in 3D printing and additive manufacturing (AM) for over 26 years, Dr Phil Reeves has wide-ranging expertise and experience of the industry. In this third article in our interview series with him, Reeves discusses the materials used in AM processes from emerging trends to the rise of open-source materials. By Tanya Weaver.

    Walk into most manufacturing companies and you’ll find display cabinets boasting a range of scale models and prototypes. Alongside the life-like aesthetic models, there may also be functional prototypes, which, depending on the age of them, are brittle yellowing parts produced by early prototyping machines. This is an area of additive manufacturing (AM) that has seen significant development in recent years with today’s materials being a far cry from those early resin parts. 

    Historically, the materials used for prototyping parts were those available at the time. “When laser sintering was invented back in 1987/88 at the University of Texas, they used nylon powder because being an additive for paint, it was the only fine powder they could get their hands on. That was the genesis for this proliferation of nylon materials we see today,” describes Dr Phil Reeves.

    “FDM was the same because when Scott Crump [co-founder of Stratasys] invented the process back in 1989, ABS was the only material he could get that worked,” he adds.

    Material testing

    Starting with these rounds of materials, as 3D printing technologies have developed and improved over the years, so too have the materials. However, as Reeves points out, there is still a lot of mistrust in material data. “The problem with AM is because the material is added layer by layer there isn’t a homogenous structure. In other words, it doesn’t have the same mechanical properties in every direction. So, it may be really strong in one direction but, depending on which way the layers are going, in another direction, it might be really poor.”

    “The issue has been that vendors over the years have played a bit fast and happy with material data, essentially using a testing regime that is not standard across the industry. So, without prescribed standards for how you should measure mechanical properties, engineers at manufacturing companies have quite rightly been sceptical of this material data. But to carry out their material testing is very expensive, which then makes them reluctant to share that data once they’ve got it,” explains Reeves.  

    This has led to several research projects that have focused on building databases of independently validated material data. For instance, early in 2020 global safety certification company, UL, published an independent study on the effects of 3D printing on polymer properties. The results of the study have been used to develop a framework to qualify materials for industrial components. The intention is that by using a trusted third-party tested and qualified material, companies will be able to mitigate the risks associated with using previously uncertified materials.

    According to Reeves, although this testing is great, the problem is that often by the time it has been completed either the material has changed or the additive machine has moved on.

    “With traditional manufacturing, a material is made and all the testing and certification then follows. If there’s a demand for that material, that’s great as it carries on being made and it stays the same. And although CNC machines might improve and get faster, that material is still relevant. But with AM, as soon as a new additive machine comes out, the material is no longer the same because it can change when it is put in that machine. So that’s the problem,” says Reeves. 

    Emerging trends 

    Materials are not only improving but as the AM industry is maturing there are also some other trends starting to emerge. Firstly, more materials are coming to market that has been formulated for a specific application where there is actually a demand for them. 

    For instance, Stratasys has two FDM machines – Fortus F900 Aerospace and F900 Pro – which process one material, an aerospace-grade material called Ultem resin. This flame-retardant, high-performance thermoplastic is used in these machines to make aerospace parts and it’s a process that has been certified by the FAA (Federal Aviation Administration). 

    “What that means is if you design a product and you certify that product for production using a certified 3D printer, it can then be made on any identical certified machine anywhere in the world and it will be guaranteed to be the same. So, it doesn’t have to be re-certified. But to develop that machine capability costs Stratasys time and money, so customers have to pay more money to buy one of those machines because of that certified process,” says Reeves

    The second trend is that companies are starting to increasingly develop materials, especially alloys, that have been specifically formulated for AM and so don’t exist for other manufacturing processes. For instance, Munich-based APWorks, an original spinout of Airbus that specialises in metal AM, has developed a material for powder-bed SLM (selective laser melting) machines called Scalmalloy, a high-strength aluminium alloy powder.

    According to APWorks, this aluminium-magnesium-scandium alloy has a unique microstructure, strength and ductility compared to other aluminium alloy powders. It has been used in a variety of applications from lightweight motorcycles, a ‘bionic partition’ for an aerospace part and an aerodynamic motorsport winglet for an Formula 1 car. In fact, in July 2020, APWorks announced that Scalmalloy has officially been approved by the FIA (Federation Internationale de l’Automobile) and added to the Formula 1 regulations as one of the additive metal materials.

    “Rather than forcing ourselves to try to use additive machines to mimic materials that were designed for other processes we’re now asking, ‘why don’t we design things for the materials that work well in additive?’ But engineers often design a product or part with a specific material in mind and then they turn to the additive world and request that part is made with that material. So, it requires a mind shift to actually design it for an additive process in a different material that will then produce a better product,” says Reeves. 

    Rise of open-source materials

    Another area that is changing is how users purchase their AM materials. Historically, if you bought a machine from a vendor, you then had to purchase materials from that vendor too. As Reeves says, in some cases the vendors even tried to lock the machines down, so users could only buy materials from them. This led to court cases challenging this as being anti-competitive. 

    “Today, we are seeing a shift toward what is called open-source material, which is actually being driven by big companies whose purchasing departments have stated, quite rightly, that they will not invest in a technology where they can only ever buy material from one place. This has now forced vendors to actually allow other companies to sell materials that can be used on their machines,” says Reeves. 

    This has resulted in several different business models emerging around how materials are purchased. The first is a very open policy where a vendor, for instance, SLM Solutions, will sell materials but will also allow users to get their materials from other companies. The next model is vendors like HP that will work with a materials company to formulate materials for their printer and will even help sell the material to customers for a license fee. Then the last model is those vendors, such as Stratasys, that will still only allow users to buy materials from them. These come in canisters with chips on, and if a user tries to put another company’s material in that machine, it may not work and, in some cases, invalidates the warranty.

    Materials value on the up

    This shift towards a more open policy has led to big materials companies now selling their own materials directly for use in AM machines. For instance, Henkel has launched a portfolio of resins under its Loctite brand and Sandvik has produced a range of metal powders, including H13 tool steel powder, that can be used by metal AM machines. “This is great for the customer. Before when the vendors were selling the material themselves and putting their trade name on it nobody really knew what it was. But now with the likes of Sandvik selling H13, which is a brand people know and trust, it adds credibility to it,” says Reeves.  

    However, it’s not as great for the vendors who traditionally would make a large revenue from sales of AM materials. The argument, according to Reeves, is would big players in the AM field like 3D Systems, EOS and Stratasys still be credible businesses if they didn’t have the revenue from raw materials? Would they be able to survive on just being machine tool vendors? 

    “If you listen to the quarterly earnings calls of companies like 3D Systems and Stratasys, which as dull as it sounds I do, you will always hear that the materials revenue was great but machine revenue was poor, and this is a common ongoing theme. So, these vendors want to hold on to that material for as long as possible because they are very reliant on revenue from raw materials,” describes Reeves. 

    While the spotlight has always been on AM technologies and the machines, it’s the materials that are playing an increasingly big role especially with their expanding use for end-use part making. 

    “AM will go the same way as other industries like CNC machining and injection-moulding where the material value eclipses the value of the machine,” states Reeves. “Put it this way, if I was an investor I’d put my money on materials not machines.”

    https://cdn.mtdcnc.global/cnc/wp-content/uploads/2021/03/23145253/Ultem-1100-is-an-aerospace-certified-material-from-Stratasys-640x360.jpg

    Are materials the next challenge for additive manufacturing?

    Having been entrenched in 3D printing and additive manufacturing (AM) for over 26 years, Dr Phil Reeves has wide-ranging expertise and experience of the industry. In this third article in our interview series with him, Reeves discusses the materials used in AM processes from emerging trends to the rise of open-source materials. By Tanya Weaver.

    Walk into most manufacturing companies and you’ll find display cabinets boasting a range of scale models and prototypes. Alongside the life-like aesthetic models, there may also be functional prototypes, which, depending on the age of them, are brittle yellowing parts produced by early prototyping machines. This is an area of additive manufacturing (AM) that has seen significant development in recent years with today’s materials being a far cry from those early resin parts. 

    Historically, the materials used for prototyping parts were those available at the time. “When laser sintering was invented back in 1987/88 at the University of Texas, they used nylon powder because being an additive for paint, it was the only fine powder they could get their hands on. That was the genesis for this proliferation of nylon materials we see today,” describes Dr Phil Reeves.

    “FDM was the same because when Scott Crump [co-founder of Stratasys] invented the process back in 1989, ABS was the only material he could get that worked,” he adds.

    Material testing

    Starting with these rounds of materials, as 3D printing technologies have developed and improved over the years, so too have the materials. However, as Reeves points out, there is still a lot of mistrust in material data. “The problem with AM is because the material is added layer by layer there isn’t a homogenous structure. In other words, it doesn’t have the same mechanical properties in every direction. So, it may be really strong in one direction but, depending on which way the layers are going, in another direction, it might be really poor.”

    “The issue has been that vendors over the years have played a bit fast and happy with material data, essentially using a testing regime that is not standard across the industry. So, without prescribed standards for how you should measure mechanical properties, engineers at manufacturing companies have quite rightly been sceptical of this material data. But to carry out their material testing is very expensive, which then makes them reluctant to share that data once they’ve got it,” explains Reeves.  

    This has led to several research projects that have focused on building databases of independently validated material data. For instance, early in 2020 global safety certification company, UL, published an independent study on the effects of 3D printing on polymer properties. The results of the study have been used to develop a framework to qualify materials for industrial components. The intention is that by using a trusted third-party tested and qualified material, companies will be able to mitigate the risks associated with using previously uncertified materials.

    According to Reeves, although this testing is great, the problem is that often by the time it has been completed either the material has changed or the additive machine has moved on.

    “With traditional manufacturing, a material is made and all the testing and certification then follows. If there’s a demand for that material, that’s great as it carries on being made and it stays the same. And although CNC machines might improve and get faster, that material is still relevant. But with AM, as soon as a new additive machine comes out, the material is no longer the same because it can change when it is put in that machine. So that’s the problem,” says Reeves. 

    Emerging trends 

    Materials are not only improving but as the AM industry is maturing there are also some other trends starting to emerge. Firstly, more materials are coming to market that has been formulated for a specific application where there is actually a demand for them. 

    For instance, Stratasys has two FDM machines – Fortus F900 Aerospace and F900 Pro – which process one material, an aerospace-grade material called Ultem resin. This flame-retardant, high-performance thermoplastic is used in these machines to make aerospace parts and it’s a process that has been certified by the FAA (Federal Aviation Administration). 

    “What that means is if you design a product and you certify that product for production using a certified 3D printer, it can then be made on any identical certified machine anywhere in the world and it will be guaranteed to be the same. So, it doesn’t have to be re-certified. But to develop that machine capability costs Stratasys time and money, so customers have to pay more money to buy one of those machines because of that certified process,” says Reeves

    The second trend is that companies are starting to increasingly develop materials, especially alloys, that have been specifically formulated for AM and so don’t exist for other manufacturing processes. For instance, Munich-based APWorks, an original spinout of Airbus that specialises in metal AM, has developed a material for powder-bed SLM (selective laser melting) machines called Scalmalloy, a high-strength aluminium alloy powder.

    According to APWorks, this aluminium-magnesium-scandium alloy has a unique microstructure, strength and ductility compared to other aluminium alloy powders. It has been used in a variety of applications from lightweight motorcycles, a ‘bionic partition’ for an aerospace part and an aerodynamic motorsport winglet for an Formula 1 car. In fact, in July 2020, APWorks announced that Scalmalloy has officially been approved by the FIA (Federation Internationale de l’Automobile) and added to the Formula 1 regulations as one of the additive metal materials.

    “Rather than forcing ourselves to try to use additive machines to mimic materials that were designed for other processes we’re now asking, ‘why don’t we design things for the materials that work well in additive?’ But engineers often design a product or part with a specific material in mind and then they turn to the additive world and request that part is made with that material. So, it requires a mind shift to actually design it for an additive process in a different material that will then produce a better product,” says Reeves. 

    Rise of open-source materials

    Another area that is changing is how users purchase their AM materials. Historically, if you bought a machine from a vendor, you then had to purchase materials from that vendor too. As Reeves says, in some cases the vendors even tried to lock the machines down, so users could only buy materials from them. This led to court cases challenging this as being anti-competitive. 

    “Today, we are seeing a shift toward what is called open-source material, which is actually being driven by big companies whose purchasing departments have stated, quite rightly, that they will not invest in a technology where they can only ever buy material from one place. This has now forced vendors to actually allow other companies to sell materials that can be used on their machines,” says Reeves. 

    This has resulted in several different business models emerging around how materials are purchased. The first is a very open policy where a vendor, for instance, SLM Solutions, will sell materials but will also allow users to get their materials from other companies. The next model is vendors like HP that will work with a materials company to formulate materials for their printer and will even help sell the material to customers for a license fee. Then the last model is those vendors, such as Stratasys, that will still only allow users to buy materials from them. These come in canisters with chips on, and if a user tries to put another company’s material in that machine, it may not work and, in some cases, invalidates the warranty.

    Materials value on the up

    This shift towards a more open policy has led to big materials companies now selling their own materials directly for use in AM machines. For instance, Henkel has launched a portfolio of resins under its Loctite brand and Sandvik has produced a range of metal powders, including H13 tool steel powder, that can be used by metal AM machines. “This is great for the customer. Before when the vendors were selling the material themselves and putting their trade name on it nobody really knew what it was. But now with the likes of Sandvik selling H13, which is a brand people know and trust, it adds credibility to it,” says Reeves.  

    However, it’s not as great for the vendors who traditionally would make a large revenue from sales of AM materials. The argument, according to Reeves, is would big players in the AM field like 3D Systems, EOS and Stratasys still be credible businesses if they didn’t have the revenue from raw materials? Would they be able to survive on just being machine tool vendors? 

    “If you listen to the quarterly earnings calls of companies like 3D Systems and Stratasys, which as dull as it sounds I do, you will always hear that the materials revenue was great but machine revenue was poor, and this is a common ongoing theme. So, these vendors want to hold on to that material for as long as possible because they are very reliant on revenue from raw materials,” describes Reeves. 

    While the spotlight has always been on AM technologies and the machines, it’s the materials that are playing an increasingly big role especially with their expanding use for end-use part making. 

    “AM will go the same way as other industries like CNC machining and injection-moulding where the material value eclipses the value of the machine,” states Reeves. “Put it this way, if I was an investor I’d put my money on materials not machines.”