For Exco Engineering's automotive customers, the bottom line is that additively manufactured die cast components can give them a distinct competitive advantage. His demonstration demonstrates how 3D-printing conformal cooling channels close to the surface of these tools results in a thermally balanced die, and how the benefits of this result in shortened cycle times, reduced scrap rates, and lower labor costs. He presents years' worth of research that supports his claims, which he supports with thermal stress simulations and real-world testing..
It is a pitch that Byleveld has made with considerable success. Exco's most important die cast parts customers are the Detroit Three automobile manufacturers, but the company's clientele includes virtually every major automotive brand in the United States. Additive manufacturing is frequently associated with environmental sustainability, but why is this so? And how can organizations...
In recent years, however, he has devoted his time and energy exclusively to additive manufacturing, an initiative that he claims was sparked by learning that one of Exco's competitors had begun experimenting with the technology."It was more out of curiosity than out of necessity," he explains. Although Byleveld claims he was given broad latitude to integrate additive manufacturing into Exco's production tools after an initial round of positive benchmarking tests — fueled by the potential to drastically reduce temperatures via 3D-printed conformal cooling channels — he says he has been given limited latitude to do so.
The die cavity insert is an excellent illustration of this. Die inserts, as the name implies, are inserted into a pocket of a die after it has been finished. Because of the geometric complexity of die inserts, they are machined separately. The use of machining inserts as stand-alone components allows the cutting tool to access the external faces of a part, but the geometry of internal cooling channels is still limited to basic linear shapes. This results in thermal imbalance, which causes a variety of problems further down the production chain due to inefficient cooling of the die during and after the casting process.
To be honest, the process of seeking out a custom die casting that was capable of producing automotive die casting parts, let alone one that could survive in an automotive aluminum alloy die casting environment, proved to be a difficult one. Byleveld chose an engine block water jacket as a benchmark part because it has a thick base and extremely thin walls, making it an excellent comparison."If you can build this part for us, we'll buy your machine," Byleveld stated in an email to several 3D printer OEMs. A spokesperson for EOS said, "EOS was the only company that accepted the challenge and stated that they were committed to succeeding no matter what it took."
"According to him, the problem with laser sintering H13 alloys is that the high concentration of carbon in the steel causes the formation of microcracks throughout the material, just as it does with traditional welding methods. Even with a properly preheated system that has been completed in the proper manner, defects will persist and result in a highly unreliable part that may receive a large number of shots one time and as few as 75 shots the next time. In Byleveld's opinion, "it's extremely difficult to produce additively."In some cases, the parts printed with H13 are cracked and have a lot of porosity, as you can see in the images."When you're injecting metal at 13,000 PSI in 20 milliseconds and you have a waterline 1 mm from the surface, if the water line bursts during the metal injection, the machine is blown open and you have to start over. It's a major source of concern for my personal safety."