Development and performance assessment of Aluminium-hexagonal boron nitride nanocomposites for next-generation electric vehicle brake pistons

Electric vehicle braking systems require lightweight pistons capable of withstanding mechanical loading, friction, and dimensional instability under pressure. In this study, Aluminium-based nanocomposites reinforced with hexagonal boron nitride (hBN) (1, 3, 5 wt%) were synthesized through ultrasonic mixing coupled with spark plasma sintering (SPS), with a pure Al serving as a comparative sample developed under similar conditions. High-energy planetary ball milling led to exfoliation of hBN flakes into nanosheets, while SPS resulted in densification with clean Al/hBN interfaces without the presence of secondary phases. Al–1 wt% of hBN exhibited the most remarkable properties, including a density of 96.71%, enhanced hardness, lower wear depth (~190 μm), wear rate of 1.92 mm 3 /m, and the formation of a lubricating tribofilm ensuring a stable friction coefficient. Moreover, this sample demonstrated higher compressive strength (~923.92 MPa) and a higher strain-to-failure ratio. Finite element analysis of the electric vehicle brake piston subjected to 20 MPa stress revealed lesser deformation for the Al–1 wt% of hBN, which indicates greater stiffness.