Synchronous improvement of electrical and mechanical performance of A356 alloy reinforced by boron coupling nano-AlNp

High strength and excellent electrical conductivity of Al alloys are highly desired in the field of power transmission. However, these two factors are usually contradictory in metallic materials. A novel boron coupling nano-AlN particles (about 0.6 wt% nano-AlNp and 0.06 wt% B) reinforced A356 alloy is proposed in this paper, which obtains excellent electrical conductivity (sigma: 46.2% IACS), high ultimate tensile strength (UTS: 300 MPa), superior yield strength (YS: 240 MPa) and good elongation (EL: 7.5%) synchronously. Contrasting with the general A356 alloy modified by Sr, the sigma, UTS, YS, and EL increased by about 8.2%, 9.1%, 4.3% and 66.7% respectively. This strategy is mainly based on boron treatment and nano-AlNp inhibiting the lapped growth of eutectic Si to ensure high conductivity, and the modification of Si, the refinement of the SDAS of alpha-Al grains and the relative homogeneous distribution of the individual or small flocculent nano-AlNp in the matrix and at the Al/Si interface to ensure high mechanical properties. (C) 2019 Elsevier B.V. All rights reserved.