Dievar 3D printing

It will be two years since we, Galvamet and VŠB, started 3D printing. The main motive for me was that since I organized a seminar on HIP and 3D printing for the Heat Treatment Association, and when Jim Shipley from Quintus presented his view on these technologies, I somehow began to suspect that without HIP it would be a problematic path. That was in 2019.

Then followed an anabasis of questioning and searching, including my participation in Euroguss in Nuremberg, or discussions about cooperation with ONE3D and doc. Paloušek. It was such a testing and discovery period; however, I remained absolutely clear in my opinion that if we want to produce critical parts by 3D printing, we must also have HIP. The logic is simple.

A) Without HIP, we may have hidden defects inside, which can result in catastrophic damage to the die insert. But we only have one piece, the one we printed, and apart from a few NDT methods, we have no way to analyse internal defects. Of course, we can destroy the part and look at the internal structure, but then we have nothing to put in the die. So, we have to increase the probability of survival of the part by including HIP. It is strange that in applications for aircraft engines today no one questions this, and in dies for high pressure casting basically everyone

B) The second reason, and this is a very practical one, is that 3D printing to perfect density is so time-consuming and financially demanding that it loses its meaning. If I do not find other synergistic effects on the critical inserts, such as comfortable cooling leading to a shortening of the machine cycle, then economically it is no better than traditional machining and formed materials. In combination with the above mentioned in point A), then doubly so. It is expensive and unreliable.

When I once met at Galvamet with the vice-dean doc. Skotnicová and Tomáš Čegan, it was immediately clear to me that I had come across the right people. And because Aleš Šlechta, the owner of Galvamet, is a visionary, he offered to pay for our “playing” at science and research. I must thank him for that, because in the two years with Tomáš Čegan we confirmed that our considerations were correct.

And what are our results? The first is 3D printing of titanium implants. The printing time was reduced from approximately 60 hours to 20 hours, and the resulting mechanical properties were identical. The porosity in the “perfect” print was around 0.08%, i.e. a density of 99.92%, while in the economical print it was 2.6%, i.e. a density of 97.4%.

The same will apply to inserts for high pressure die casting, although the final values are still being investigated. But we can already say that economic printing brings us both cost and time savings, and in combination with HIP, security.

Although Dievar printing is still in the sample phase, the results are very promising. We are already at 40 J impact strength, which I consider a great result. It is almost 100% better than the forged material. The only limitation is the size of the HIP that we have available. Diameter 130 mm, height 300 mm. But let’s be honest, it’s still just a game.

6 years have passed, and when I look around the tool shops and foundries, no significant progress can be seen. Quite the opposite. And since I personally “managed” one of the largest tool shops in the Czech Republic for 6 years, in Plastimat Liberec, now Magna Exteriors, I completely understand. There is no time for experiments there. The manufactured dies must work at 100% and without the risk of failure. The tool shop, or rather the foundry, needs a reliable solution. And if those who have printers want to make a name for themselves, they must offer this security above all.

In the Czech Republic, there are now, according to my estimate, more than 20 metal printers using the SLM method. For these demanding applications, however, the printer itself is only a partial part of the problem. If the complete production chain is not considered, i.e. the printer, HIP, vacuum furnace, then this sector will stagnate.

Three years ago, I did a study for Czechimplant on how to centralize 3D printing for orthopaedic implants. It was a project that would provide metal 3D prints for all entities in the field of orthopaedics or traumatology. In Czech there are 61 hospitals and 11 clinics.

Something similar would probably be really useful for tool shops. Eventually, their number will certainly exceed the number of hospitals or clinics. If a tool shop or foundry needed an insert manufactured by 3D printing, they would prepare the complete data in Procast, Solidworks, Aucocad, and send this data electronically to the Print Centre. Here, 3D printing specialists would edit the data into final SLT files, and after customer approval, they would then use them to enter the printer. After printing, all post-processes, such as stress relief annealing, platform separation, HIP and heat treatment, would be carried out at the same workplace. See work flow example.

What would be the benefits?

• First, the era of total fragmentation of the 3D printing market would end
• Quality at the highest level would be ensured by specialists who will be the leaders in the field
• Everything would be done in one place, without the need to run between 3D printing, HIP provider or hardening shop with the necessary equipment, and therefore in an acceptable time
• The number of printers and their size would be in line with the real needs of tool shops. For operational reasons, it would be possible to reserve each printer only for a given material, to eliminate problems with changing powder (Dievar, H13, 1.2709, M2, etc.)
• Just as vacuum furnaces or HIPs must be validated to AMS 2750, printers could also be regularly certified for reproducible activity. Auditing such an operation would be a pleasure
• There would be a guarantee for the necessary “certainty” that existing systems do not provide

Is this science fiction? For now, yes, but the future probably has no other path. And the investment in such a workplace? I estimate 10-15 million EUR in total. A nice amount, but when I calculate that those more than 20 printers represent a similar amount, then maybe it won’t be that much when it comes to results.

Jiří Stanislav

February 28, 2025