Kinetics of Phase Transformations in the Zn–0.8% Li Alloy

Recent research has shown that zinc alloys are among the most promising materials for bioresorbable (biosoluble) implants. This paper presents the phase transformation of a new promising bioresorbable alloy, Zn–0.8Li. It was found that after quenching from 300°C, the alloy has a structure consisting of a mixture of two isomorphic supersaturated solid solutions: a Li solution in the zinc phase and a Zn solution in the primary crystallites of the LiZn₄ phase. During subsequent aging for 20–50 h at room temperature, the alloy undergoes natural aging, during which thin (approximately 1 μm thick) zinc plates precipitate in the LiZn₄ phase, and submicron LiZn₄ particles precipitate in the zinc phase. The phase transformation pattern during aging was obtained based on the results of X-ray diffraction analysis, SEM microstructural studies, and electrical conductivity studies at different stages of natural aging. The maximum microhardness value is achieved after 48 h of aging.