Fig. 2: Projected barycentric phase diagram.

4D phase diagram of the Al−Cu−Co−Ni−Fe system at 1500 K projected into a pentagon, where each vertex represents an element. Solid solutions are colored in blue while intermetallic phases are colored in red. A 2D point’s distance from each vertex is related to the composition corresponding to that point. Binary tie lines connect vertices, lying along edges of the polygon for adjacent elements and extending across the polygon for non-adjacent elements. Ternary compositions lie within a triangle connecting three elements, and quaternary compositions lie within a quadrilateral. Some positions in the pentagon correspond to multiple compositions, as the projection of the 5D space into 2D leads to the collapse of multiple 5D points into the same 2D point.