The Importance of Heat Conduction and Global Temperature Fields in the Laser Powder Bed Fusion Process

Laser powder bed fusion (LPBF) is an additive manufacturing process for metallic components, typically used to fabricate structures out of high-strength materials like Ti–6Al–4V. Due to the laser-based melting process, knowledge about heat conduction is essential. Here, the influence of process heat can be classified into a local effect with melting and re-melting and a global impact with complex heating and cooling cycles. This contribution investigates the capability of measurements with thermocouples to analyze the global temperature effect. With the provided setup, the evolution of interlayer temperature changes was studied under LPBF process conditions. It is shown that the complex thermal history in the samples is highly dynamic in the time domain with rapid temperature increases and cooling rates up to 172 \(\mathrm {\frac{^\circ C}{s}}\) . During the printing process, it transforms into a quasi-static temperature profile characterized by a global temperature with small temporal variations as the number of layers proceeds. The thermocouple measurement is evaluated as a reliable method that provides repeatable experimental data. This tool should be further used to gain necessary knowledge about the LPBF process, especially the process-determining thermal evolution within components.