On the final day of our Frontiers in additive manufacturing series, Glenn Rees, Head of Engineering at Conflux, discusses the many design freedom challenges, commercial points of interest for metal additive manufacturing, and more. .
You come from a motorsport background. Can you tell me a bit about the differences and similarities in this field in terms of design, innovation and commercialization?
Glenn Rees: I worked in motorsport in the UK and Australia from the late 90s and during that time witnessed the emergence of CAD systems for the growth of additive manufacturing. Motorsport has always embraced lightweight, structurally efficient design. As such, it has generally been an early adopter of cutting-edge technologies, especially those that can add value through efficiency improvements, whether that be increased performance or reduced processing time.
Manufacturing techniques in motorsport are typically composites, metal fabrication and CNC machining. Additive manufacturing is also making inroads – particularly with plastic parts, but also now with structural metal components that would have conventionally been manufactured subtractively by CNC machining.
Design for Additive Manufacturing (DfAM) shares some of the fundamental principles of conventional manufacturing, including the concern to always focus on the total performance of the end product. The AM printing process allows for greater freedoms such as lattices, small fins, and complex channels, but also imposes certain restrictions on geometry, especially regarding build direction and overhanging elements.
Innovation varies from category to category and is mainly driven by regulation and level of investment. There’s always an innovative mindset among engineers and that’s something that helped me a lot at Conflux Technology – it’s part of the culture. From a broad perspective, the level of innovation in AM is huge – we are literally on the frontier of a new technology!
Metal AM is constantly seeing new applications, and these have gone from simple parts like supports to more and more complex, like heat exchangers. Why are 3D printing heat exchangers desirable?
Glenn Rees: I think the freedoms that come with building a piece one layer at a time open up really innovative design. It allows complex and intricate geometries that can be printed in a single monolithic structure. This gives us a lot more freedom to fine-tune the geometry based on fluid boundary conditions, which results in better performance.
But these are not always easy to achieve. What are the challenges for these complex applications?
Glenn Rees: The challenges are many! One of the main ones is printing minimum wall thicknesses to achieve performance goals in a given volume. This is intrinsically tied to the detailed settings set for 3D printers – settings that ensure build optimization, consistency and efficiency.
The removal of powder from complex monolithic parts with narrow channels must be considered right from the design phase. There are also limitations in designing forms and understanding the impact of different geometric angles on the print outcome. All of these things and more must be considered and overcome. There are also a number of cost savings that have long been touted and are beginning to be realized as the industry matures…
To take advantage of this and reduce the complexity of a BOM, AM promised to shorten and simplify supply chains and allow service bureaus or manufacturers to print multiple parts in one place, at the point assembly or nearby. There are intellectual property challenges that need to be addressed to achieve this. All of the production instructions for a part must be communicated to the machine that performs the printing, which represents a large part of the value in IP for application companies like Conflux. Fortunately, there are several software and hardware solutions being developed in this space that secure all build instructions and settings.
Focusing on commercialization, what other developments in the industry are you looking forward to?
Glenn Rees: I think the two main areas are dramatic improvements in machine speeds and the maturing of certification processes for AM parts.
Currently, the hourly cost of running the AM machine is the largest component of the cost of goods, and it has remained stubbornly high. I am encouraged to see a number of companies developing new generations of machines with much higher productivity. It will be a game changer when we can envision mass production at rates that compete with other manufacturing approaches.
There’s one sweet spot where this technology can really add value now, and that’s in smaller heat exchangers. With these, the benefits of increased performance, reduced build and development time, and customization can be realized at a competitive price.
And each time we increase our productivity, we become that much more competitive with other manufacturing processes.
Another key objective for the industry is to mature the processes and standards relating to the certification or validation of parts for production. Encouragingly, I see announcements of many other metal parts for aerospace applications, as well as automotive and industrial. In addition to processes and standards, there are technological advancements that will help you.
We scan our parts with CT scans and assess quality, porosity and other attributes using proprietary software – Conflux Quantify – for example. This level of insight is essential for proving the consistency of complex monolithic parts. Companies are leveraging AI and real-time scanning during printing to verify and improve the quality of their AM processes.
Overall, I am very optimistic that these developments will support major adoption of metal AM for complex applications.
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