Effect of part thickness on the microstructure and tensile properties of 316L parts produced by laser powder bed fusion

Additive manufacturing provides a unique possibility to manufacture parts with advanced design and thin-walled structures. To explore thin-wall capacity, laser powder bed fusion was employed to fabricate 316 ​L samples with different section thicknesses. A detailed microstructure characterization was then carried out, and tensile properties were assessed. It was found that reducing the part thickness did not affect the microstructure but did reduce the tensile properties. Samples with 1 ​mm thickness exhibited the lowest yield strength of 457 ​± ​11 ​MPa and elongation to fracture of 49 ​± ​20%, while the tensile properties improved when the sample thickness was increased to 3 ​mm. The 3 ​mm thick samples generated tensile properties comparable to those of standard dimensions. The results emphasize that part thickness must be considered when assessing mechanical properties and must be adjusted when performing design optimization and simulations of samples produced with laser powder bed fusion.