Determination of Rational Parameters of LPBF in Order to Reduce Porosity

Keywords

LPBF – method, porosity, crystallization, Key Holes, Lack of Fusion, power, scan speed

Abstract

Pores in the material manufactured by the LPBF method can significantly affect the stress distribution and the formation of the structural state during crystallization. Large pores of irregular shape are especially dangerous, which often represent defects such as non-fusion and keyhole. The relationship between the depth/width ratio of a single track and the formation of large pores was studied for Inconel 718 with changes in manufacturing parameters (power 110…230 W, scanning speed 450…950 mm/s with a step of 50 units). It was established that the rational depth/width ratio of single tracks for experimental samples: 0.56…0.82. In this case, the rational width of a single track is 80…120 μm and the depth is 100…135 μm, at a power of 110…230 W and a scanning speed of 450…950 mm/s.

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