Microstructure and Mechanical Properties of AlSi10Mg/NbC Composite Produced by Laser-Based Powder Bed Fusion (L-PBF) Process

AlSi10Mg metal matrix composites with varying weight percentages (wt.%) of niobium carbide (NbC: 0, 3 and 6 wt.%) were produced utilizing a laser-based powder bed fusion process in three printing orientations (0 degrees, 45 degrees and 90 degrees) to improve the mechanical properties of the composite. The effect of NbC in AlSi10Mg on reflectance, densification, microstructure, wear resistance, micro-hardness, tensile and compression behavior were examined. The reflectance of AlSi10Mg powder was reduced to 26.94% with the addition of 6 wt.% NbC. Furthermore, the addition of 6 wt.% NbC in AlSi10Mg increased the relative density (rho(R)) to 2.59%. The average grain size of all printed samples was <= 10 mu m. The wear rate of the composite was reduced to 6.32% against EN-31 and 32.6% against SiC counter body at 0(0) printing orientation with 6 wt.% NbC. The mechanical properties of the AlSi10Mg/NbC composite were enhanced, including micro-hardness (167 HV0.5 at 6 wt.%), ultimate tensile strength (393 MPa at 3 wt.%) and compressive strength (851 MPa at 6 wt.%). However, the formation of intermetallic compounds reduces tensile strength over 3 wt.% NbC. The printing orientation also affected the composite's mechanical properties.

Automated summary

In this study, AlSi10Mg metal matrix composites with varying weight percentages of niobium carbide were produced using a laser-based powder bed fusion process. The addition of niobium carbide improved the density and mechanical properties of the composite, but excessive amounts of niobium carbide reduced the tensile strength.