Before revision: The main compounds formed are usually Au5Al2 (white plague) and AuAl2 (purple plague), which both form at high temperatures, then Au5Al2 and AuAl2 can further react with Au to form more stable compound, Au2Al.
After revision: The main compounds formed are usually Au5Al2 (white plague) and AuAl2 (purple plague), both of which form at high temperatures, then Au5Al2 and AuAl2 can further react with Au to form more stable compound, Au2Al.