Improving Surface Properties of AlSi10Mg Fabricated by Cold Spray: Mechanical Milling is a Tool for Fabrication of Composite ZrN/AlSi10Mg Particles

Abstract

In this study, the possibility of employing ZrN/AlSi10Mg composite powders with 10, 20, and 30 wt% ZrN and a low-pressure cold spraying (CS) unit to enhance the surface properties of AlSi10Mg obtained through laser powder bed fusion (LPBF) is investigated for the first time. A high-energy ball mill is used to produce composite powders from AlSi10Mg and ZrN powders. ZrN/AlSi10Mg powders are sprayed onto the surface of LPBFed AlSi10Mg at a pressure of 0.7 MPa and a temperature of 400 °C. It is demonstrated that the utilization of composite powders facilitates a uniform distribution of ceramic particles in the coating and reduces the share of their losses during the CS process to 2%. It is found that the microhardness and elastic modulus of composite coatings increase with increasing mass fractions of ZrN, while the wear rate (WR) decreases. A change in the wear mechanism from adhesive to abrasive is observed. It is possible to increase the microhardness and elastic modulus of the LPBFed AlSi10Mg surface with a coating containing 30 wt% ZrN by 43% (193 ± 5 HV_0.1) and 62% (105 ± 9 GPa), respectively, and reduce the WR by 25% (8.26 ± 0.09) × 10⁻⁴ mm³ m⁻¹.