How selective is the TU Delft

TU Delft: Process to reduce heat generation in SLM 3D printing

The SLM (selective laser melting) process is suitable for complex constructs, due to the heat generated by the laser and the layer-by-layer cooling during printing, properties and surfaces can change. In the article “Towards Design for Precision Additive Manufacturing: A Simplified Approach for Detecting Heat Accumulation”, a Dutch research team from the TU Delft presented two methods for the early detection of unfavorable heat distributions.

The team has developed two processes in order to develop new topology optimization methods (TO), which are precisely tailored to the SLM process. This method can be used to adapt the design early on or to analyze existing geometries.

“In order to bring thermal aspects of additive manufacturing into a TO system, a suitable AM ​​process model is required. This becomes problematic because a highly accurate process model is computationally very expensive and the integration into a gradient-based TO system becomes even more laborious, ”the researchers explained in the article. “Therefore, in this study, a physically based but greatly simplified approach is proposed to identify heat accumulation zones in a given design. The computational gain offered by the simplification makes it possible to integrate the heat accumulation detection scheme into a TO system. "

Cost reduction through design analysis

To reduce the cost of thermal analysis, two methods have been developed. In the first method, the model is cut in layers, just like with the print itself. The cooling behavior only depends on a few previous layers. This assumption can save a lot of computing time. In the second method, the transient thermal behavior is translated into a static thermal behavior.

The researchers try to quantify geometries and thereby simplify the design analysis, in doing so they found out that the geometry is a very large factor but cannot be seen on its own.

"The computational advantage offered by the proposed method enables the development of a physically-based topology optimization method that would be beneficial for designing precise AM components," the researchers conclude. "The next step for this research is to combine the developed method with a density-based topology optimization by penalizing design features that are prone to heat accumulation during each iteration."

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I am 26 years old and a mechatronics student at the Technikum Wien. I have been in the industry for 10 years with interruptions, working in maintenance, automation and construction. I only had my first contact with additive manufacturing during my current studies, but was immediately gripped by the possibilities that this technology brings us. I'm curious to see where this technology will take us.