Enhanced Mechanical Strength and Electrical Conductivity of Al–Ni‐Based Conductor Cast Alloys Containing Mg and Si

Abstract

The electrical conductivity (EC), mechanical strength, hot tearing susceptibility (HTS), and related microstructure of Al–xNi–0.55Mg–0.55Si conductor alloys (x = 1–4 wt%) are investigated. Adding Mg and Si into Al–Ni‐based alloys, numerous β″/β′ precipitate after T5 and T6 treatments, thus significantly improving the EC and mechanical strength. The HTS of the alloys reduces significantly as the Ni content increases, mainly because of an increase in the eutectic Al–Al3Ni and a reduction in the grain size. Under T5 condition, the tensile strengths increase gradually with the Ni content and reach a medium strength level, with yield strength (YS) of 158–205 MPa and EC of 47.1–50.7% IACS. After applying T6, all alloys achieve a high strength, with YS of 246–287 MPa and EC of 47.7–51.1% IACS. However, the strength decreases with increasing Ni content. In general, the Al3Ni–0.55Mg–0.55Si alloy presents a better trade‐off among HTS, YS, and EC among the four alloys investigated. Due to its excellent properties (EC of 49.4% IACS and YS of 178 MPa in T5, and EC of 49.7% IACS and YS of 250 MPa in T6), the Al3Ni–0.55Mg–0.55Si alloy is a promising material for the fabrication of Al conductor cast alloys.

Research Progress on Thermal Conductivity of High-Pressure Die-Cast Aluminum Alloys

“…Another work also used the direct aging process at 180 • C in Al-Ni-Mg-Si conductor cast alloys. After the aging treatment, the microhardness and electrical conductivity both increased mainly because β ′ and β ′′ nanoparticles precipitated from the substrate [148]. This kind of method is suitable for aluminum die castings because of the supersaturated solid solutions.…”