Ion implantation was used to introduce 20 at.% Si into anA‐15 Nb3Al0.9Si0.1substrate. The surface was depleted of Al by a diffusion anneal. The Al deficiency was replaced with Si by successive implantations. The surface structures were determined from reflection electron diffraction photographs. After depletion and implantation, the sample surfaces had a disordered bcc structure. A subsequent 800 °C anneal transformed these surfaces intoA‐15 Nb3Al0.2Si0.8by epitaxial recrystallization.