Ball-milled Al–Sn alloy as composite Phase Change Material

The present study concerns a fully metallic solid-liquid composite Phase Change Material based on an Al–Sn Miscibility Gap Alloy produced by powder metallurgy, including its ball-milling, compression and further sintering heat treatment. The materials obtained by different routes display a narrow melting temperature range at about 230 °C, corresponding to the phase transformation of Sn- or of Sn-rich eutectic. The microstructures obtained by this manufacturing process lead to form-stable PCMs, which can keep their shape and prevent active phase leakage in service conditions. Ball milling of metal powders as mixing technique allowed to obtain a very fine microstructure, resulting in stability of thermal response and improvement of mechanical properties. Among the investigated Al–40Sn mass% samples, the most promising were those compressed at 240 °C followed by sintering at 500 °C. [Display omitted] •Powder mixing by ball milling before hot compaction provides a fine microstructure.•Microstructure refinement obtained after thermal treatments prevents Sn leakage.•Both thermal and mechanical stability are observed up to 285 °C.•The best production process is hot compression at 240 °C and sintering at 500 °C.