Influence of processing parameters on AlSi10Mg lattice structure during selective laser melting: Manufacturing defects, thermal behavior and compression properties.

• The correlation between defects and thermal behavior is discussed, and the forming causes of defects are analyzed. • A physical model is proposed to simulate the thermal behavior of melt pool under different processing parameters. • Processing parameters have significant influence on macroscopic morphology but have little influence on dendrite spacing. Selective laser melting (SLM) is a kind of material forming technology which involves many processing parameters. The appropriate processing parameters are very important to the forming quality of manufactured samples. In this paper, the influence of laser power and scanning speed on the manufacturing defects, thermal behavior and compression properties of AlSi10Mg lattice structures during SLM were systematically investigated. By observing the macroscopic and microscopic morphology of manufactured samples, it was found that the processing parameters had a significant influence on the strut diameter and internal porosity but had little influence on the dendrite spacing and grain size. A physical model considering thermal loss and thermal conduction in temperature field was proposed to simulate the thermal behavior of melt pool under different processing parameters. The results showed that the thermal behavior was more sensitive to the laser power, and the manufacturing defects were related to the transient temperature and dimension of the melt pool. The digital image correlation (DIC) method was adopted to analyze the strain distribution of manufactured lattice during the compression process. Meanwhile, the relationship between processing parameters, thermal behavior and manufacturing defects was discussed in detail. Finally, based on the optimal processing parameters (250 W-1400 mm/s), the accuracy of manufactured lattice structure was verified by finite element method. The research results can provide a reference for the selection of processing parameters for manufacturing AlSi10Mg lattice structure. [ABSTRACT FROM AUTHOR]