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Additive Manufacturing in a defence context; can we 3D – print weapons yet?

Additive Manufacturing in a defence context; can we 3D – print weapons yet?

This blog post provides a brief review of contemporary additive manufacturing processes that can be used to augment defence supply chains and improve the product development lifecycle. 

Additive Manufacturing (AM) or ‘3D printing’ has been around for a while now, and advances in technology have brought the technology into the mainstream with many hobbyists having desktop 3D printers capable of high quality, albeit small, prints in a range of polymer materials. So, what does this mean for the defence industry and when can we start printing real weapons and tanks? The answer is: although the technology is still maturing, it’s already happening now and the possibilities to utilise this technology in defence are expanding 

The applications for additive manufacturing are quite diverse. While once thought of as the domain of the prototype and R&D departments only, this technology is now being used much more widely to address logistic issues (printing parts on demand), for bespoke production of low quantity and customised or unique high-performance parts (think satellites and missiles), and to produce new design geometry and part topologies to optimise existing structures. 

In this blog I want to explore some recent examples of defence-related AM achievements and see how this technology is evolving and where it can add value to existing defence processes. The first example highlights not just the potential benefits of this technology, but also the real ethical and security implications that AM brings with it.

The 3D Printed Grenade Launcher 

The US Department of Defence (DoD) has been working on AM technology for some time, investing more than US$ 13.2bn of their budget in 2018 alone1. In 2017 a team of US Army defence engineers and researchers set out to design and build a fully 3D printed grenade launcher – aptly called RAMBO (Rapid Additively Manufactured Ballistics Ordnance). 

The team set out to rapidly evolve a design through the concept, prototype and testing stages, with an overall development lifecycle measured in months, not years. They achieved this and test fired not only the weapon, but also 3D printed ammunition for it (I assume the casing) successfully, demonstrating the capability to rapidly bring serviceable equipment to an operational level in a fraction of the time it traditionally takes. 

This demonstrates the ability of AM to reduce development cycles and allow designers to be more agile and iterate quickly in the process, but it also highlights some potential risks with new technology frequently outpacing government laws and legislation. Granted, not everyone is as well funded as the US Army, but it’s not beyond imagination that AM technology could be exploited by malicious actors to obtain weapons otherwise not easily procured, and for this reason it’s important governments and the defence industry are aware of potential security risks. 

At this moment, highend commercial AM machinesespecially those designed to print metal partsare out of financial reach of most civilian hobbyists. However, as the technology matures and advances this may not remain the case; many students already have access to such technology via education and research institutes, and this will require care on the part of these organisations to ensure it is not misused. 

 IMAGE1

The “RAMBO 3D Printed Grenade Launcher (Image: Digital Trends) 

 

The next example of AM in defence illustrates that it’s not just leadtimes that can be reduced; material properties can also be refined to produce parts of equivalent or greater strength with a lower mass, and these will become a new part of the logistic supply chain. 

Printing Spare Parts on Demand 

The next example of AM in defence illustrates that it’s not just leadtimes that can be reduced; material properties can also be refined to produce parts of equivalent or greater strength with a lower mass, and these will become a new part of the logistic supply chain. 

One of the key challenges to any defence force is logistics; making sure you have the right support in place is critical to success on the battlefield, and having spares available, in theatre, to support operational platforms is essential. It’s impractical and expensive to deploy every spare part you might need to a conflict zone, and even using predictive failure analysis and condition monitoring doesn’t address this. 

The ability to 3D print a spare part might solve this challenge, with operators able to access a library of models for manufacture on demand, indeed Capability Acquisition and Support Group (CASG) here in Australia has already taken notice of the US Marines using a deployable shelter to print parts as part of their AM roadmap for the future (reference article here). 

From a technical perspective, the US Army Research Laboratory has been looking at this scenario and found that by using a special steel alloy (AF96), previously used in munitions, but in a powder form, they could 3D print parts using a fusion or sintering process to replicate OEM parts.  These replicas exceed the structural performance of the original OEM parts. A replacement impeller fan for the M1A1 turbine engine was successfully manufactured and tested (reference article here), and although it’s not approved as an alternative source of supply yet, the conditions are set for this trend to continue. 

In parallel to this, the US Air Force has taken the idea one step further, with a range of parts in both polymer and metal materials being printed and installed on a C-5 Galaxy aircraft (reference article here) to reduce sustainment costs. The group, led by the Rapid Sustainment Office (RSO), even collaborated to print some parts in a gunship grey polymer resin, removing the need for painting. 

Replacement parts that are 3D printed can also be redesigned to improve their efficiency, taking advantage of AM processes that achieve geometric forms not previously possible (or at least very expensive) with traditional materialremoving techniques such as machining. 

Bespoke and Limited Rate Production 

Closer to home, I recently had the opportunity to meet some of the team from Zenith Tecnica – a New Zealand based AM company (www.zenithtecnica.com) – exhibiting their impressive technology and range of parts at the Avalon Airshow. This company specialises in titanium metal printing using a sintering process that produces highly detailed parts with superior mechanical properties. 

One of the key markets for companies like Zenith Tecnica is aerospace and satellite production, where a high number of very technical, bespoke components drive a compelling business case away from traditional manufacturing processes. In aerospace environments, mass and strength are often key design factors, and AM opens a new frontier for parts that are optimised during the design process using Artificial Intelligence (AI). 

AI algorithms can be programmed to take an existing 3D part and, given certain parameters and interfaces, optimise the geometry or topology for strength and/or mass reduction (structural efficiency). These algorithms are able to take full advantage of shapes and form only made possible through AM, and in contrast to convention design. Engineers and scientists recently used this process during their research to redesign a Boeing 777 aircraft wing (reference article here), using a supercomputer that took five days to come up with a radical new design that was five percent lighter than the current structure, potentially saving hundreds of tonnes of fuel per year. 

 IMAGE2Artificial Intelligence used to re-design a Boeing 777 Wing (Source: Nature) 

 

3D Printing and Innovation 

The advances in AM are also facilitating technical innovation in defence and locally, Australian industry have been keen to get on board. At the 2018 Land Forces conference in Adelaide, for example, Luminact displayed a compact communications node concept, integrated to a small ATV (check out the article here) which features several 3D printed prototype parts that were designed and manufactured rapidly inhouse in the lead up to the event. 

The Australian Defence Science and Technology (DST) Group has also worked with local industry and academia to showcase the possibilities of AM, repairing metal components for F/A-18 and C-130 aircraft (reference article here) and gaining certification for their airworthiness. And, while many challenges for AM are still being addressed, the fact its adoption and use has come this far already bodes well for the future of AM innovation and the full effects of this manufacturing technology in the era of an Industry 4.0 revolution. 

Given the rapid growth and advancement of AM technology, it certainly has a role to play in the development of an advanced Australian industrial base, and its adoption will continue to enable new and rapid ways of developing capabilities and equipment that could help to give Australian soldiers an edge, in a changing and challenging strategic environment. 

About the Author: 

Andrew Skinner is a Director and co-founder of Luminact, a Chartered Mechanical Engineer, and holds a Masters in Project Management. Andrew has over ten years’ experience working in defence projects, both with large prime contractors, as well as consulting to Defence.