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Fraunhofer ILT: Making Tungsten Carbide-Cobalt Cutting Tools with LPBF 3D Printing

Obviously, the Fraunhofer Institute for Laser Technology ILT does a lot of work with lasers, and, in the same vein, with metal 3D printing processes that use lasers. Now, it’s teaming up with scientists from the Institute for Materials Applications in Mechanical Engineering IWM and the Laboratory for Machine Tools and Production Engineering WZL, both at RWTH Aachen University, to investigate laser processes for the 3D printing of cutting tools made of tungsten carbide-cobalt (WC-Co).

The new AiF project – “Additive Manufacturing of Machining Tools out of WC-Co – AM of WC-Co” – began on October 1st 2019 and will last for 30 months; funding is provided by the Otto von Guericke e.V. working group of industrial research associations.

Cutting tools made of WC-Co are very heat- and wear-resistant, which is what one generally wants in this type of application, but it’s not easy to use conventional methods of manufacturing to create them. Complex sintering processes are currently used, but it’s not ideal, as only a restricted amount of geometrical freedom is possible, and it’s expensive and difficult to introduce complex cooling structures into the tools as well.

The process development aims to generate a homogeneous, almost dense structure of the WC-Co-composite, as shown here in this SEM measurement. [Image: Institute for Materials Applications in Mechanical Engineering IWM, RWTH Aachen University]

One of the project goals is to create cutting tools with integrated complex cooling geometries in order to ensure longer tool life. That’s why the Aachen researchers are looking into Laser Powder Bed Fusion (LPBF) 3D printing for WC-Co cutting tool fabrication, which offers near-net-shape production for generation of cooling structures within these tools, and far more design freedom. This technology requires users to carefully choose their process and material parameters in order to create components with strength that’s comparable to what could be achieved with conventional manufacturing methods.

For the past few years, Fraunhofer ILT scientists have been researching a major problem in the LPBF process – temperature distribution in the part. Conventional systems slow down the cooling process with a heated base plate, but with LPBF, the metal powder is melted where the laser touches it and cools down quickly, which can cause cracks and tension.

Fraunhofer ILT has been working with adphos Innovative Technologies GmbH on this issue, and together the two created a system which uses a near-infrared (NIR) emitter to heat the component from above to over 800°C. This system is what Fraunhofer ILT and its fellow Aachen researchers are using to process tungsten carbide-cobalt material for cutting tools in the “AM of WC-Co” project.

Under the scope of the project, the researchers are investigating the process route all the way from powder formation and 3D printing to post-processing and testing the components. Together, they will qualify the materials and processes that will replace complex sintering processes in fabricating these cutting tools.

Preheating the machining plane with the NIR module significantly reduces stresses in the laser-manufactured component. [Image: Fraunhofer ILT]

3D printed WC-Co cutting tools will have a hardness comparable to those made with conventional manufacturing methods, but because of the cooling structures that the LPBF process can be used to create, they will have a longer service life. Additionally, the NIR emitter system developed by Fraunhofer ILT and adphos can lay the groundwork for processing refractory alloy systems in the future.

At formnext 2019, in Frankfurt from November 19-22, you can stop by the Fraunhofer Additive Manufacturing Alliance booth D51 in Hall 11 to learn more about the collaborative “AM of Wc-CO” project.

Discuss this story and other 3D printing topics at 3DPrintBoard.com or share your thoughts in the Facebook comments below. 

[Source: Fraunhofer ILT]

The post Fraunhofer ILT: Making Tungsten Carbide-Cobalt Cutting Tools with LPBF 3D Printing appeared first on 3DPrint.com | The Voice of 3D Printing / Additive Manufacturing.

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RMIT: 3D Printed Milling Cutter That Cuts Titanium Alloys, Thanks to Jimmy Toton

3D printing is walking its path slowly but surely into the field of aerospace and defense manufacturing. Due to the demands of high performance and rigorous precision, every step given in this direction has to be crafted to the detail to achieve perfect execution.

Jimmy Tonton, a PhD candidate from RMIT University of Melbourne, Australia, has achieved important progress in this field by developing high-quality cutting tools than can now be 3D printed. For this research, Toton has partnered with the Australian Defence Materials Technology Centre (DMTC) and industry partner Sutton Tools. The outcome of this collaboration is a set of steel milling cutters able to cut through Titanium alloys with the same or at times better results than conventional steel tools.

Picture of the high performance milling cutter

This is the high-performance steel milling cutter 3D printed by RMIT researchers. Credit RMIT University

Because the high resistance of metals used for aerospace and defense, creating an efficient cutting tool is quite challenging and expensive. The strength and high-quality execution required to perform those cuts let us imagine the numerous difficulties that Toton had to overcome to achieve a successful design. The milling cutting tool has to be strong enough to cut through metal while keeping the layers resulted from 3D printing unified and all its parts built strong enough to avoid cracks. It also must be finished to a very smooth surface roughness in order to remain functional. 

The set of milling cutters represent the first convincing demonstration of 3D printed steel cutting tools that can cut strong metals. Toton’s work is a clear demonstration of the technology´s potential achievement for the development of 3D printing tools. Consequently Toton has been awarded the 2019 Young Defence Innovator Award and $15,000 prize at the Avalon International Airshow.

Jimmy Toton inspecting his tool

Jimmy Toton inspects a 3D printed steel milling cutter. Credit RMIT University

The technology used to make the milling tools is  Laser Powder Bed Fusion, also called Laser Metal Deposition, Selective Laser Melting  and Direct Metal Laser Sintering. Which is an additive manufacture process in which metal powder is fed onto a metal base and a laser beam melts the material added forming a metal pool that layer by layer forms the object. This technique lets the object to be built with complex internal structures and demanding external surfaces. Although as we know metal 3D printing processes require several finishing and post finishing steps in order to work well. These may include tumbling for several days, HIP, precipitation hardening, shot peening and other steps. These kinds of cutting tools do not magically appear out of the machine but are a result of a number of process steps. 

Some of the potential that this project holds are improvements in productivity, time-saving in tool making, costs savings, reduction of material waste and the possibility of creating tools that fit a very specific purpose and in so doing overcoming supply chain constraints. This is all good news for manufacturing. Toton is now working towards establishing a print-to-order capability for Australia’s advanced manufacturing supply chains.

In his own words:

“Manufacturers need to take full advantage of these new opportunities to become or remain competitive, especially in cases where manufacturing costs are high,”

“There is real opportunity now to be leading with this technology.”

DMTC Chief Executive Officer, Dr Mark Hodge, said:

“Supply chain innovations and advances like improved tooling capability all add up to meeting performance benchmarks and positioning Australian companies to win work in local and global supply chains,” he said.

“The costs of drills, milling cutters and other tooling over the life of major Defence equipment contracts can run into the tens, if not hundreds, of millions of dollars. This project opens the way to making these high-performing tools cheaper and faster, here in Australia.”

Sutton Tools Technology Manager, Dr Steve Dowey, said:

“This project exemplifies the ethos of capability-building through industrial applied research, rather than just focusing on excellent research for its own sake,”

RMIT’s Advanced Manufacturing Precinct Director and Toton’s supervisor, Professor Milan Brandt, said:

“Additive technology is rising globally and Jimmy’s project highlights a market where it can be applied to precisely because of the benefits that this technology offers over conventional manufacturing methods,”

Tooling and cutting tools may not be the first thing that you think of when coming up with 3D printed products. This showcase of their use indicates just how versatile 3D printing can be. Toton has shown us that parts that are not traditionally thought of as high value are still mission critical enough to 3D print in costly metal printing processes. We expect many more people to apply metal 3D printing to metal and polymer consumables and tools in the coming years.