Effect of fabrication process parameters and graphene reinforcement on mechanical behaviour of additively manufactured AlSi10Mg alloy: A molecular dynamics simulation study

Context

AlSi10Mg alloy is among the most widely recognised aluminium alloys due to its dimensional stability and exceptional properties for additive manufacturing. However, the alloy’s performance can be improved and optimized through appropriate reinforcement and control of the manufacturing process parameters. This work focuses on the impact of process parameters (laser power, scan speed and layer thickness) and graphene reinforcement on the mechanical properties of SLM-fabricated AlSi10Mg alloy. The results indicate that, increasing the laser power within the studied range enhances both tensile and compressive strength. Furthermore, reducing the laser scanning speed improved these properties, although further reduction beyond a threshold value minimizes the impact. However, increasing the layer thickness while maintaining the same laser power reduces the material properties, the effect can be mitigated by supplying more laser energy. The addition of graphene as reinforcement has markedly improved the composite properties, improving its elastic and plastic behaviour. The graphene reinforcement also improved the stiffness, yield strength, toughness, and ultimate strength making it a highly effective way to enhance the AlSi10Mg alloy performance.

Methods

In this study, molecular dynamics (MD) was performed to model the selective laser melting (SLM) process using LAMMPS (large-scale atomic/molecular massively parallel simulator) software. The simulation setup was programmed to analyse the impact of process parameters, including laser power (500, 600, and 700 μW), scanning speed (1, 1.5, and 2 nm/ps) and layer thickness (two and three-particle layer system) on the mechanical properties (tensile and compressive strength) of AlSi10Mg alloy. Additionally, the impact of graphene reinforcement was also examined using nano-scale simulation. The simulation provides insights into both the SLM process and the mechanical behaviour of the alloy and its composite under different processing conditions.