Elevating Al7039 alloy performance through copper addition for advanced industrial applications

• Copper addition enhances hardness (193 BHN) and thermal conductivity (173.5 W/m.K). • Optimized Al7039/Cu alloy provides a turned product with a smooth surface (0.578 µm Ra). • Microstructural analysis confirms refined grains and reduced defects in alloy casting. • Shell mold casting ensures uniform composition and minimizes porosity in Al7039/Cu. • Al7039/Cu alloy offers a cost-effective alternative for mold tooling and. Expanding consumer demand for plastic products in both household and industrial sectors necessitate advanced mass production methods like plastic injection molding. Achieving optimal performance in this process largely depends on the mold's core and cavity properties. However, conventional materials often lack the combination of hardness, thermal conductivity, and surface finish required for superior molding outcomes. This research introduces an alloy that cost-effectively unifies these essential characteristics, offering a promising alternative for modern mold tooling. Aluminum alloys, known for their low density and excellent thermal and mechanical properties, are prevalent in automotive, aerospace, and mold tooling applications. Addressing the need for improved surface finish, enhanced heat transfer, and increased hardness; this study investigates the addition of 4 %, 8 %, and 12 % high-purity copper (98.96 % Cu) to Al7039. The alloys were prepared via induction melting with magnetic stirring, cast into shell molds, and machined to standard geometries. Each property was tested thrice for consistency. Surface roughness was measured using a JB-4C precision meter, while hardness and thermal conductivity were assessed using Rockwell B testing and steady-state linear methods, respectively. Microstructural evaluations were performed with a 4XC-W inverted metallurgical microscope. Results show that 4 % copper achieved the lowest surface roughness (0.578 µm) and highest thermal conductivity (173.5 W/m. K), whereas 8 % copper yielded the highest hardness (193 BHN). Nonetheless, greater copper concentrations introduced defects like porosity and microcracks, indicating the necessity for further optimization. Overall, selective copper enhancements significantly elevate Al7039’s performance, expanding its applicability in high-performance engineering.