A research on the surface morphology, microstructure evolution and wear property of selective laser melting Al₂O₃/P20 composites

Laser powder bed fusion of the steels used in the plastic injection mould industry: a review of the influence of processing parameters on the final properties

“…As expected, a finer grain structure was observed in the middle of the melt pool (higher energy intensity), and coarse grains were detected in the most peripherical zone of the melt pool (heat affected zone in the weld) [120,121]. After tempering, the martensite phase is progressively transformed into tempered martensite and fine carbides precipitated between the martensite laths [121].…”

“…The production of P20 steel parts by LPBF has not been studied much yet. Just three studies are included in this review [115,120,121], all related to the last three years. As for the previous cases, Table 3 presents the inputs of the LPBF process for P20 steel.…”

“…The energy densities used were similar to the ones of 420 stainless steel and H13 steel (78.0 to 333.1 J/mm 3 ). In all these studies, the layer thickness was 30 µm and the laser power varied from 100 to 200 W. Two studies used a scanning speed of 800 mm/s [115,120], and one, 350 mm/s [121]. The hatch spacings chosen were in the range of 80 µm to 105 µm.…”

“…The hatch spacings chosen were in the range of 80 µm to 105 µm. Only one study refers to the scanning strategy adopted (zig-zag strategy) [120].…”

“…For P20 steel, Lin et al [120] (load of 5 kg and 600 rpm for 20 min; counter-body: tungsten balls) report two important points: (i) the defects on the surface can be beneficial for tribological properties because they can act as a reservoir for wear debris, minimising third body abrasion, and (ii) the metal matrix composites, and particularly hard particles, improve the wear resistance and lubrification of the base material.…”