Abstract:The majority of industrial aluminum casting alloys exhibit low thermal conductivity, which is insufficient for effective heat transfer in electronic devices. The objective of this investigation was to develop new aluminum casting alloys with high thermal conductivity. The impact of alloying elements on the thermal conductivity of pure aluminum was examined, and the relationships among microstructure, thermal conductivity, and the mechanical and corrosion properties of Al-Zn-Ca-(Cu,Mg) alloys were explored. The findings indicate that in the as-cast state, the structure of the alloys consists of α-Al and a eutectic containing the (Al,Zn)₄Ca phase. Following the solution heat treatment, the (Al,Zn)₄Ca phase is spheroidised, and thermal conductivity of the alloys increases, reaching over 75% that of pure aluminum. However, the heat-treated alloys exhibit low mechanical properties: tensile yield strength <60 MPa, ultimate tensile strength <160 MPa, and elongation at fracture >15%. The alloys demonstrate satisfactory fluidity and low hot tearing susceptibility. With the exception of the alloy containing copper, the alloys exhibit low corrosion rates, estimated at approximately 0.02 mm/a.

Key words: aluminum alloys; thermal conductivity; phase composition; fluidity; hot tearing susceptibility; corrosion rate