Metal Additive Manufacturing
Recently there has been huge growth and interest in the whole area of additive manufacturing or 3D printing. In 3D printing, polymer based parts are made on simple devices using internal movements and controls similar to desktop printers. But instead of ink, the ‘print’ heads extrude a metal, plastic or other material which is used to grow the 3D part layer by layer. Here we explore the uses and applications of this evolving technology with a particular focus on metal additive manufacturing.
When was the Arrival of Additive Manufacturing Technologies?
Additive manufacturing processes are much in demand right now and have made their way into mainstream news, capturing the imagination of the general public because of the vast potential on offer.
Our infographic below shows how additive manufacturing has revolutionised industry.
Additive manufacturer processes have been around since the 1980s when Charles Hull invented stereolithography, a type of metal additive layer manufacturing which is still used today.
From the birth of stereolithography, the technology behind what is described as 3D printing was created, generating even greater possibilities. There are now a number of metal additive layer manufacturing companies and the market is competitive and thriving, driving development ever-onwards.
Using metal additive manufacturing processes doesn’t just deliver advantages, it completely rewrites the possibilities. Shapes and designs that couldn’t previously even be conceived of are now entirely viable, such as parts with scooped out centres. It’s not just the shape which has become possible with additive metal manufacturing, but the lack of compromise. There’s no weakening of the structure and no need to try and weld several parts together, creating vulnerable join areas. Instead, the process can generate a complete shape in its entirety, by carefully layering and bonding materials together to create the desired outcome.
What are the Advantages of additive manufacturing?
Across many applications the process delivers significant advantages, infact it completely rewrites the possibilities including:
- Design freedom – enables rapid iterations and flexibility to make design improvements right up to production. Shapes and designs that couldn’t previously even be conceived of are now entirely viable, such as parts with scooped out centres. It’s not just the shape which has become possible with additive metal manufacturing, but the lack of compromise.
- Ultimate customisation and tailoring – make one-offs as easily as production batches, this is ideal for limited runs, country variants, etc.
- Material diversity – Performance from a wide choice of materials to create extremely strong and corrosive resistant parts.
- Rapid prototyping – Business case justification is made much easier through rapid production of models and prototypes, plus process benefits when in production. see more about rapid prototyping here.
- Reduce material wastage – the additive process (rather than subtractive) leads to savings in material. Additionally, virtually no write-offs will occur, compared to traditional methods.
- Strengthening – Ability to create complex shape with internal strengthening features. There’s no weakening of the structure and no need to try and weld several parts together, creating vulnerable join areas. Instead, the process can generate a complete shape in its entirety, by carefully layering and bonding materials together to create the desired outcome.
What are the Benefits of 3D metal printing?
Across many sectors 3D metal printing is providing an effective alternative to existing processes allowing cost-effective production even at low volume as well as shortened lead times, reduce part count and offer many more advantages including:
- Speed of production – Components can be produced quickly and directly from a CAD model dramatically reducing production time. This also applies to tooling, which can be printed in full or AM can be applied to areas of tooling, which has become faulty.
- Eliminate processes – Eliminate production support processes such as expensive tooling.
- Environmental benefits – Lower environmental footprint through the reduction of waste (all non-used powder is re-used). More conventional methods of machine production leave as much as 90% of the original materials on the factory floor, not just wasteful but unnecessarily detrimental to the environment.
- Stockholding benefits – Deliver savings through improved product design. Costs are also eliminated by removing the need to hold onto expensive inventory parts. Materials can simply be “printed” as and when they’re required, saving on not just space but cost too.
- Small production runs – Metal is particularly beneficial for products which won’t be made in high volumes and offers a way to create customised shapes and designs far more economically than previously possible.
How is it Changing the face of design?
3D metal additive manufacturing has changed the entire design and manufacturing process, creating possibilities which were hitherto unthinkable.
In the past, design models were created based on what could physically be created, with the manufacturing process driving creation and implementation. With the unveiling and expansion of metal printing, the reverse is now true. The primary design is back in the driving seat with concepts and ideas pushing forward, with practicalities over production not a primary concern.
AM also makes it possible for the entirety of the geometry to be developed at the same time, with both the inner parts of a component and the outer shell given equal attention. Creating the piece as a single unit creates strength but with the potential of adding valuable functional elements to the core, some of the results cannot be replicated using any other type of manufacturing.
What Types of metal are used?
It’s possible to use both alloys and pure metals for additive manufacturing with stainless steel; titanium alloys, aluminium and nickel are commonly used. Precious metals can be used too, both for engineering and jewellery purposes, with silver and gold both responding well to AM techniques.
This great variety of metal and alloys means that it’s possible to select the perfect material for the design, fulfilling criteria such as core strength and also cost. Not all types of metal powder are suitable for AM; the particle size and its spherical geometry can often determine whether it’s appropriate. Once the AM process is complete, the final design can undergo electro polishing to improve the surface finish. This may be required for cosmetic reasons or to deburr the surface, particularly for those items which may be exposed to abrasive substances.
All metals can go through electro polishing if desire, even the small and more fragile components, as there’s no chemical, thermal or mechanical impact created during the process.
What are the applications of metal additive manufacturing?
From its roots in prototypes, metal printing has rapidly become a core technology which has a practical application in a number of different industries. Often described as belonging to a group known as “disruptive technologies” metal printing has the capacity to completely revolutionise the way in which things are made. It’s not currently used in high volume, mass productions, but instead offers the most value where precision engineering is vital or where customisation and flexibility are key.
Fuel nozzles in the aerospace industry are a great example of how this technology is used in practice. The new designs created with the use of metal printing techniques are five times more durable and 25% lighter.
It’s these kinds of components where metal printing delivers the greatest benefit, providing the capability to create any geometric shape. Products which will only be made for a short time or in low numbers, where there’s great geometric complexity, those which are extremely small and precise and prototypes and molds all could use metal additive manufacturing rather than conventional means to achieve a far better end result.
What are Examples of Industrial Use?
Although additive manufacturing is seen as a relatively new technology, it has been around for several decades and is already in widespread use across a number of different industries.
Although the concept of 3D printing has only recently captured the public’s imagination and been reported in the media, there’s a number of different industries which have been increasingly using the technology to revolutionise their manufacturing processes.
Examples of just a few of these industries are as follows:
There are a huge number of applications within aerospace, with both interior and exterior parts benefitting from the technology. Functional engine parts such as turbine blades as well as interior parts such as cockpit equipment and seat belts can be made using additive manufacturing.
One important application is aeroplane engine blade repair using laser metal deposition (LMD). Fiber lasers can be used to repair fault lines, fill holes and repair engine blades back to pristine condition one layer at a time, these are so perfect the repairs are invisible to the naked eye and also improve safety of the aeroplane. This often involves working with steel and titanium alloys, which are very commonly used on engine blades.
The ability to create lightweight components which are aerodynamic and can be formed in a variety of complex geometric shapes is paramount in importance to the success within the aerospace industry. Streamlining designs by being able to create components in a single piece (e.g. fuel nozzle), rather than having to join them together results in improved strength as well as better performance.
In aerospace, having lightweight parts is of particular importance. This isn’t just for their superior aerodynamic properties but also to save money too. Lighter designs burn less fuel and so are far more economical to run.
There are a number of other ways in which the process helps to save money but for aerospace, the lightweight construction really is an important factor.
Electronics and semiconductors
Two industries which are bound tightly together, electronics and semiconductors have the capacity to achieve great things with the use of metal additive manufacturing. By combining the latest developments such as quantum dot LEDS, created via 3D printing techniques, and bioscience, there’s the possibility that superior prosthetics and medical aids could be created such as smart contact lenses and reactive prosthetic limbs.
Being able to print on 3d surfaces means that electronics no longer need bulky circuit boards or wires and cables; the entire package can be shrunk down into a micro size and made far more attractive for the commercial market.
When it comes to car production, the process is already used in a number of different applications across the body, interior and the engine.
However, the development of different materials to be used with processing such as laser melting and sintering leaves the way open for even greater utilisation in the future. Exhausts, bumpers and fluid valves are currently made using these methods, but as the range of materials increases, more complex parts such as engine components and electronics could be created.
Combining nanotechnology with additive manufacturing could create a greater scope too. Experts believe that this could make metals such as titanium strong and stable enough to create a dense material product.
Other material such as carbon fibre is already in widespread use, desirable for its light weight yet extreme toughness and strength. All of these innovations also apply to the booming e-mobility industry too.
The jewellery industry makes extensive use of additive manufacturing technology.
Metal rapid prototyping in the jewellery industry is particularly used for bespoke and complex designs, customer personalised jewellery (e.g. inscriptions), reducing the time to market, small batch production and also the production of unique jewellery pieces.
The field of medicine is one which is constantly evolving and changing, battling to overcome the effects of age and disease on the human body.
Additive manufacturing has already proven to be a useful tool in the fight, allowing doctors to provide far more precise surgical outcomes and heal more easily.
Bodily implants are the perfect target for additive manufacturing as it requires absolute accuracy and a customised approach. Additive manufacturing makes this a far more cost-effective process because of the ease in which individually-designed prototypes can be created with just a few clicks of the mouse.
One example of this would be 3D printed implants for spinal disorders. Frequently made with titanium these implants can very cost-effectively fix a number of spinal issues, by printing “body parts” to the specifics of the patient.
The medical industry use of additive manufacturing extends to dentistry too, with crowns and bridges being manufactured via additive means for almost a decade already. The ability to create geometrically complex dentures from impressions and scans means a far more comfortable fit for the patient in the long term. Most of the innovations in this industry naturally use non-metallic 3D printing.
Research and academia
Additive manufacturing is used in a large number of research and academic settings for a variety of purposes. These are often at research laboratories, which are at the cutting-edge of use of the technology as you would expect.
Many projects are underway to create prototypes and models using metal rapid prototyping (and other materials too) for rollout into industry. By sharing the .STL files researchers can collaborate/share knowledge to speed up research and improve ROI.
Often research departments with manufacturers test additive management to create business cases as to whether the technology would deliver ROI for commercial rollout and evaluated AM compared to existing production techniques.
Academia has embraced additive manufacturing, and this is now a part of many University syllabuses. Students and researchers alike can receive training in these simulated labs, which often have access to top-quality equipment. Academia also has produced educational items, e.g. fossils, artefacts, skeletons, body parts, etc. using 3D printing methods.
The scientific industry makes extensive use of additive manufacturing in its quest to advance the human race through new scientific breakthroughs.
One such breakthrough was the 3D printing of chalcogenide glass, which caused a stir in scientific communities. A whole array of lower-cost equipment and tools can be 3D printed, opening up scientific experiments to a larger body of Scientists.
How do SPI Lasers enable Selective Laser Sintering (SLS)?
Our Lasers have been used in all types of additive manufacturing of metals, and we have delivered specific benefits to the process. In particular our Fiber Lasers bring benefits that can help manufacturers improve the quality of the printing, reduce costs, increase productivity and support quality control.
Specifically, we can provide the following process performance advantages:
- Back reflection protection.
- Fast temporal response with high stability.
Use pulse shaping to achieve the following outcomes:
- Faster pulse rise times – shorter pulses deliver higher throughput and finer processing.
- Power stability at switch on leading to less instability seen in work-piece.
- Temporal pulse shaping an advantage as the process uses individual pulse in ‘point & shoot’ or continuous vector mode.
- Back reflection protection because even for powders some users report issues.
- In process monitoring. Using the back reflection signal from PIPA fibre provides a unique opportunity for real time non-invasive process monitoring.
For more information please see our selective laser sintering and melting page.
Why choose SPI Lasers?
We are the experts in this field and understand what you need from our Lasers to get the very best results. Our Lasers deliver pinpoint accuracy and are used in a number of different industries, from aerospace to medicine, consistently performing at the top of the field.
Additive manufacturing is one of the brightest new prospects and an industry which is set to continue to develop rapidly. Our Lasers have a proven track record of delivering excellent results within a variety of additive manufacturing processes, including the additive manufacturing of metals.
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