Characterization and hydrolysis mechanism of soluble Al-Mg-Ga-Sn alloys in hydraulic fracturing applications.

To engineer a dissolvable Al-Mg-Ga-Sn aluminum alloy material suitable for multi-stage hydraulic fracturing and sealing tools, an array of alloys was fabricated using high-temperature casting with varying concentrations of Ga and Sn. The compositions were designed such that the ratio of Ga to Sn remained constant at 1. The objective was to examine the influence of Ga and Sn content on the mechanical properties of the alloys and their reactivity with water. Results indicated that with 1.0 wt% of both Ga and Sn, the alloy displayed a ultimate tensile strength (σ b) of 182±1 MPa, elongation (δ) of 33.8±0.8 %, reduction of area (φ) of 11.6±0.9 %, yield strength (σ Sc) of 161±1 MPa, relative compressibility (δ) of 63.0±1.0 %, and relative expansion of the cross-section (φ) of 170.8±0.9 %. Additionally, when subjected to water at 90℃, the alloy achieved a maximum dissolution rate of 3.0±1 g·h-1·cm-2. Upon contact with an aqueous environment, an electrochemical reaction ensues where aluminum atoms in the matrix lose electrons, transforming into Al3+ ions within the solution. Concurrently, Sn2+ and Ga2+ ions migrate to the surface oxide film, substituting Al3+ ions at the grain boundaries, which induces vacancies in the oxide film, reducing its resistance to further ionic penetration and densification loss. This study elucidates the macroscopic process mechanism of the interaction between water-soluble alloys and aqueous media, and proposes a corresponding microscopic mechanism. • Al-Mg-Ga-Sn soluble aluminium alloy can be completely dissolved in water and aqueous solution. • This alloy exhibits high ductility, demonstrated by an elongation rate of 33.82%. • The dissolution behaviour of the alloy is regulated by both gallium and tin elements. • The use of this material to make sealing tools can greatly improve the efficiency of extraction. • This material introduces a pioneering concept to the development of soluble metal composite materials. [ABSTRACT FROM AUTHOR]