Although the Covid-19 pandemic has had a very real impact on the sector, both globally and locally, all signs are that additive manufacturing (AM) – popularly called 3D printing – is set to grow rapidly in the coming years, both in South Africa and around the world. That was a clear consensus at the recent annual conference of the Rapid Product Development Association of South Africa (Rapdasa) – the representative body of the local AM sector – held in Pretoria at the International Conference Centre of the Council for Scientific and Industrial Research (CSIR).

“Globally, the short-term impact of Covid-19 on AM was a substantial deceleration of its growth rate, but no actual contraction occurred,” highlights Loughborough University (in the UK) computer-aided product design specialist and a Rapdasa conference keynote speaker Professor Ian Campbell. “But AM showed itself to be a great responder to the critical needs created by Covid-19. This has likely given the technology a great boost.”

“At the human level, Covid has been terrible, but it placed a lot of focus on AM technology, globally, from the media,” agrees Rapdasa 2021 chairperson Marius Vermeulen. “This was for two reasons. First, the rapid nature of the technology, which resulted in many product developments during the pandemic, aimed at combating it, which were only possible because of the speed AM provides. Second, the beneficial impact the technology can have on logistics chains: AM allowed the local manufacture of certain products (for example, face shields).”

One major development, worldwide, was the creation of ‘3D Printing Farms’, which used dozens, scores or even hundreds of AM machines to rapidly produce essential medical equipment. On the other hand, AM is an industrial process that requires human supervision and involvement. And people working in AM were and are as susceptible to Covid-19 as everyone else, and as affected by lockdowns and other restrictions, with the result that, at least in South Africa, non-medical production with AM came to a halt.

Nevertheless, the overall effect has been to greatly increase both public and industry awareness of AM. “I believe this will lead to a greater uptake of AM in future years,” opines Campbell. “In South Africa, supply chain problems resulting from the impact of Covid have stimulated consideration of what input components, previously imported, could be produced locally through AM,” points out Vermeulen.

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AM involves creating objects one layer at a time, using a raw material feedstock that can be powder, wire or resin. The material is then melted or cured into the desired shape, layer upon layer. This allows the creation of incredibly complex shapes, with little waste of material. Indeed, AM allows the creation of shapes that cannot be produced as single units by conventional manufacturing techniques, or indeed cannot be produced by conventional manufacturing at all. (It should be noted that AM is possible only because of computerised design and control systems.)

Polymer AM was originally dominant because it was easy to process polymer powders. But many very important potential applications, especially in the aerospace and medical devices sectors, need the strength that only metals can provide. For them to adopt AM, metal powders, that can be produced in the necessary quantities, had to be developed first. A lot of work has been done in this regard, with important results.

“One of the big global trends is the growth of metal AM,” reports Campbell. “This started off 20 years ago, on a small scale. Now it is approaching the size of polymer AM – certainly in monetary terms.”

Another major global trend is the development of extremely powerful computer-aided design systems, and in particular ‘generative design tools’. These allow the creation of very complex designs that can now fully exploit the ability of AM to produce very complex shapes.

“In South Africa, we’re expecting the AM sector to grow over the next five years, with at least linear growth rates and they could even become exponential,” points out Vermeulen. “There’s no indication that Covid will negatively affect AM trends in South Africa over the long term.”

In the very short run, business will be tight, because in South Africa the technology has been used a lot during the early research and development phases in the development of new products, and many AM companies provide such services to established conventional manufacturers. However, post-pandemic, this business has slowed down significantly as the conventional industries have cut their spending back during their recovery phases. “But in the longer term, there are encouraging trends, especially regarding the aerospace and medical devices sectors.”

There is a clear desire in South Africa to establish a ‘titanium value chain’, based on the country’s significant titanium reserves and resources. Titanium powder is a most valuable raw material for AM, and the combination of titanium and AM has the potential to make the country a major international supplier of complex high-value aerospace and medical devices parts and products. This could, in turn, help revive the South African manufacturing sector and create skilled jobs.

The local development of titanium and AM technology capabilities has been supported by the Department of Science and Innovation (DSI). Regarding AM, the best known example of DSI support is the Aeroswift large metallic AM machine, hosted in Pretoria by the CSIR. Although, in recent times, the Aeroswift project has been severely affected by the financial difficulties of its private-sector partner company, it created a lot of expertise and experience in AM in South Africa. That is now bearing fruit, in other endeavours in the country.

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Arguably, the most important single outcome of experience from, and expertise developed with, the Aeroswift machine has been the development of the local Hyrax metallic AM machine by Pretoria-based start-up Aditiv Solutions.

“Hyrax is a 100% in-house design and development,” explains company chief systems engineer Jacobus Prinsloo. “The prototype is now finished and undergoing tests and we demonstrated it at Rapdasa 2021. Our core business will be building and selling these machines.”

The Hyrax uses the form of AM known as laser-based powder bed fusion. This technique uses powdered material (originally mainly polymers but now also metals); the powdered material is melted (usually by lasers or electron beams) into the desired shape, again layer upon layer.

Key members of the Aditiv team worked on the Aeroswift programme, gaining much experience there. “Due to the lessons learned and the experience gained on the Aeroswift project, we were able to fast-track the Hyrax development by avoiding the pitfalls of such a complicated machine,” affirms Aditiv chief mechanical engineer Pieta Ferreira. “The Hyrax is a completely new design that boasts the same and better specifications compared to other in-class commercial machines.”

The Hyrax is quite a substantial machine and can build objects with a volume of up to 200 mm diameter by 250 mm, in nonreactive materials, such as stainless steels, maraging steel, cobalt chrome and Inconel, and reactive materials such as aluminium and titanium.

Its 400 W laser is a single-mode Yb fibre instrument and its optical system is a post- objective galvo scanner (both laser and scanner are imported from Germany). It has a focus diameter of between 80 micrometres and 5 400 micrometres and can produce layers with a minimum thickness of 30 micrometres. The inert gas it uses in the process chamber is argon or nitrogen.

“Traditionally, AM machines are very expensive in South Africa, because they have to be imported,” notes Ferreira. “So, the local sector is focused on aerospace and medical devices manufacturing, which have the need for the low-volume, high-value parts for which AM is ideal. The idea behind Hyrax is to reduce the cost of AM for South African companies, allowing other industries to make use of the technology, such as mining or general engineering companies.”

Even with imported key components, the Hyrax is much cheaper than an equivalent machine imported into the country. And it is already making an impact: even before testing of the prototype had been completed, the company had received orders for three of the machines. The customers have agreed that these three machines be ‘pre-production’ units; all subsequent machines will be full production standard units. The first of the ‘pre-production’ machines will be delivered to North-West University next month, while the other two will be delivered next year.

Aditiv was set up 26 months ago, aided by seed incubation funding from another South African company, Quant Solutions. Aditiv is now financially self-sufficient and is operating from factory space it is renting at the CSIR’s ‘Future Factory’ facility. Development of the Hyrax was, however, significantly delayed by the Covid-19 pandemic. “It delayed us by about a year,” says Ferreira. “Many of the manufacturers and suppliers were closed or understaffed and steel shortages also created a challenge. Furthermore, getting hold of internationally sourced components was very difficult.”

The impact that the Hyrax is already having on the local AM sector is shown by the fact that, prior to its launch, there were only ten or eleven AM machines in its category in the entire country. The initial trio of orders for the Hyrax will increase this total by some 30%!

“We’re in talks with other possible clients, and believe that we’ll be able to sell even more machines in the next year or two,” reports Prinsloo. “The amount of interest we’ve received at Rapdasa 2021 is very encouraging. All the signs are pointing towards growth. The sales pipeline is looking good. It’s healthy.”

For the future, the company is, Ferreira reports, “definitely thinking of exports”. But only after they have gained more experience with supporting local customers. And it also has plans to develop and sell larger AM machines, in due course.

Building Up

“If you look where South Africa started from, 20 years ago, and with very small AM efforts during the first five to ten years, the rate of growth in its AM sector is now impressive, and it is catching up with other countries,” highlights Campbell. “Indeed, in some areas, South Africa is a world leader. These include large-scale laser sintering, with the Aeroswift machine, some of the medical work, and work with precious metals, especially platinum. The South African government has been extremely supportive of AM, and this has helped create these world-leading niches for the country.”

“The local AM sector is now developing to the point that we need to consider developing specialist training programmes for future workers in the sector,” highlights Vermeulen. “We need to estimate what the demand requirement for AM workers is. This is a very good sign. Indeed, nothing we see signals this industry is cooling down in South Africa. We see people from industry developing new products in many new sectors, even in sports equipment. It’s no longer just about projects spun out of academia or research institutions.”