The second generation of solid-state laser powder-bed fusion metal additive manufacturing machines will be deployed to produce complex and niche parts for industries over the short-term, and will support increased local manufacturing and industrial activities, says Council for Scientific and Industrial Research (CSIR) senior researcher Dr Lerato Tshabalala.
The pilot machine, called Aeroswift and developed through collaboration between the CSIR and aviation company Aerosud, has been producing a variety of components and parts for a range of industrial sectors as part of the testing and validation phase in their Innovation centre, says Aeroswift programme manager, Marius Vermeulen.
The validation phase proved that the technology can produce components with complex designs. While the technology is typically not cost competitive for the manufacturing of low-cost, mass produced parts, the ability to produce complex parts ensures a competitive advantage in a range of applications when compared to imported components or making them locally via traditional manufacturing processes, he explains.
Tshabalala highlights that, while the equipment is expensive, industrial hubs in key parts of the country can play a role in serving as viable and relevant producers of niche, high-value products and industrial equipment components to support the local industry.
Through a partnership of the departments of Science and Technology (DST) and Trade and Industry, Tshabalala expects these machines to be more broadly used by these hubs in the near future.
Producing components, bits and tools for industry in South Africa is a viable way to use advanced and high-technology manufacturing platforms to support industrial activity, as well as the broader transition to more advanced and specialised manufacturing, says Vermeulen.
“The pilot project for the commercialisation of the laser-based powder-bed fusion additive manufacturing technology is producing competitively-priced components and parts for South African industrial companies,” he highlights.
The ability to produce application- and industry-specific components, tools and bits locally will allow local industry to retool more quickly and reduce supply chain delays, while also boosting the local manufacturer’s agility and ability to change production to meet demands, says Tshabalala.
The powder-bed fusion additive manufacturing process starts with a computer-aided design (CAD) model that is then translated into a series of thin layers. A layer of metal powder is placed on a build plate before a solid-state laser and an array of mirrors melt the powder of the first layer into the required shape. Subsequent layers are then built up to form the final product, explains Vermeulen.
“Powder-bed fusion is not a quick process, but it can produce highly complex parts in ways that well known industrial production processes, such as injection moulding, casting and machining, cannot,” he says.
This dramatically widens the design complexities that can be accommodated, and has also contributed to direct improvements of the components. Vermeulen points out that many examples exist within industry where the technology has been used, for example, to increase efficiency of injection moulding tools by producing tools with complex and efficient cooling channels.
Tshabalala specifically highlights that powder-bed fusion is well suited to produce complex designs in highly durable materials, such as titanium, and this is where the gap exists to support local industry and produce internationally competitive products for export.
“Including such complex cooling channels within components cannot be done using injection moulding or machining of a cast part. While only certain applications or products are suitable for additive manufacturing, the new technology helps to support industrial research and drive development,” avers Vermeulen.
Additionally, additive manufacturing can also lead to improvements of existing components and parts, he adds. For example, a component traditionally made up of 31 parts is now produced as a single part in titanium, with an added advantage of being lighter and more durable.
“Suitable high-value, low-volume applications for advanced manufacturing technology are present in space, marine, aerospace as well as industrial tooling. Crucially, the technology allows for technical design complexity, meaning the components can fit better, be lighter or contain internal features that are normally impossible to attain, is time-consuming or costly to produce with traditional machining or injection moulding.”
The Aeroswift team tested the production of dozens of different components for a range of industry sectors in order to explore the relevance of the technology for such components and applications. Some of the components include turbine parts, unmanned aerial drone bodies, control sticks for the Advanced, High Performance Reconnaissance light aircraft, fuel strainers, brackets and bicycle components.
The team also tested the production of complex geometric shapes and even chess pieces to determine how to nest various elements within other parts during the production process and how to increase the volume of parts the machine is able to produce in each batch.
“While the Aeroswift team usually assesses the viability of producing a component or part using powder-bed fusion, we also attempt to solve technical challenges with our clients. This is achieved partly by exploring the intended uses or applications of the components and working with the clients’ engineers and designers to ensure parts are optimised for the manufacturing process.”
Sometimes the way in which the parts are designed is aligned to the technology, and in other cases the design is altered to capitalise on the capabilities of the machine. This design process can lead to the components being altered for easier production or in ways that improve their function, says Vermeulen.
“Direct collaboration between researchers and industry is an effective way to support the commercialisation of technologies whilst ensuring that industry understands the role that the new production technologies fulfil and what their main applications are.”
A good example is the production of an aerial drone structure. Here the team set specific parameters for battery and motors location, but then collaborated with a company called Altair which used software and an algorithm to design the shape of the body based on load cases extracted from the data of real stresses experienced by four-motor aerial drones.
This project combined a variety of new production technologies and techniques, and this combined method is one of the hallmarks of modern manufacturing, and fits into the connected and digital Fourth Industrial Revolution (4IR) paradigm, he adds.
Production partners in local industry, including for tools and dies, provide a means to scale up the impact of new manufacturing and industrial technologies, confirms Tshabalala.
Partnering with small manufacturing companies to provide them with printed metal parts as a routine supplier or establishing additive manufacturing machines as the core of small businesses within industrial hubs are some of the proposed commercialisation models.
However, Tshabalala notes that an industrial hub model can also help to leverage the academic and research capacity available by providing for universities, universities of technology, innovation agencies and industry organisations with space to collaborate directly with industrial companies.
Further, other additive manufacturing techniques, can be used to produce other parts and components, or to do repairs to existing parts as part of these industrial technology hubs.
The CSIR also has a laser-based metal 3D printing system, which can use a CAD drawing to repair the external surfaces of a component, such as the leading edges of turbine blades.
While the two technologies differ in their suitable applications, they can be complementary and can form part of 4IR technology hubs, she says.
A core programme of the Intsimbi Future Production Technologies Initiative, is aimed at supporting South Africa’s productive sectors and empowering local companies to produce fundamental industrial components.
South Africa needs to build its tooling manufacturing capacity to become globally competitive if the country wants to create more jobs.
Import substitution can be a valid and sustainable use of additive manufacturing technologies, but Vermeulen believes that the country should investigate developing products for export beyond only local industrial needs.
“Whether we use technologies under licence, or develop and commercialise our intellectual property, either way we can retain productive capacity in South Africa and improve local industrial capacity. This will also drive these companies to adopt newer technologies and methods to remain competitive and contribute to transitioning our industrial base to the 4IR.”