Precipitation Behavior of Sc and Zr in Severe Plastic Deformed Al

摘要

The elements of Sc and Zr were added to pure Al for improving thermal stability and refining grain size. Sc was presented on boundaries and Zr dominantly on matrix in as cast state. After homogenization treatment, Sc was dissolved mostly but Zr retained in matrix; though the two elements were presented on the same location in Al-Sc-Zr alloy. Semi-coherent Al_3Sc in Sc added alloy was precipitated during severe plastic deformation, and shown (001)_(matrix)//(001)_(Al_3Sc) orientation relationship with matrix. Al_3Zr in as cast Zr added alloy was shown the orientation relationship (011)_(matrix)//(100)_(Al_3Zr), and partially retained and dissolved with increasing deformation. In the Al-Sc-Zr alloy, retained Al_3Zr had the role of nucleation site for Al-Sc precipitates so that Al_3Zr mainly coexist with Al-Sc precipitates.