For more than five years, I have been helping companies to establish conformal cooling using metal 3D printing. But even though it was known that actually only tool inserts made of 1.2709 can be produced by metal 3D printing as standard, at almost all trade shows, lectures or tool making events, the first question was always: "Can you also produce the steel H11/H13 by metal 3D printing?" Today, I can answer "Yes".
Until now, the higher carbon content had prevented the process-reliable production of components of these materials in metal 3D printing. But by heating the substrate plate to 500 degrees Celsius, these very materials can be printed with process reliability.
Preheating of 200 degrees Celsius was the industrial standard in metal 3D printing. This was a compromise: Preheating induces less residual stress. On the other hand, it has the disadvantage that it makes powder recycling more difficult and needs longer cooling time at the end of the build-job.
No More Compromise Necessary
Metal 3D printing in powder bed has become the most successful, industrial additive process for metals over the past 15 years. However, with the gradual establishment in series production, the demands of industrial companies on the process are also increasing. In addition to the general desire for shorter production times, the main demands are for higher component quality and reliable initial production - even complex parts should therefore succeed right from the start without approximation tests.
With the new TruPrint 5000 from TRUMPF in Ditzingen, the compromise between less residual stress and recyclability is no longer necessary. This machine was designed and developed for 500 °C applications from the very beginning, so it can maintain the necessary process stability even with steels containing carbon.
Trials at TRUMPF were able to confirm that, thanks to 500-degree preheating, high-carbon alloys such as H11 (1.2343) and H13 (1.2344) can really be processed reliably with metal 3D printing. This is particularly interesting for the tool and die industry, as this sector prefers to use these steels and can derive a particularly large benefit by integrating conformal cooling into printed inserts.
In the following, I would like to show how 500-degree preheating with 3D printing in the powder bed can reliably process high-carbon alloys for the first time.
Further, I would like to describe how preheating technology can be integrated into the manufacturing process in such a way that maximum utilization of the metal 3D printer is achieved and - despite the high temperatures - the residual powder can be recycledwithout any problems.
