After　a　standard　heat　treatment,　the　morphological　evolution　of　gamma　＇　precipitates　in　the　directionally　solidified　Ni-base　superalloy　M4706　with　time　is　investigated　during　thermal　exposure　at　800　degrees　C.　In　contrast　to　previous　results,　it　is　found　that　as　the　average　particle　size　increases　from　241　to　368　nm　with　increasing　aging　time　up　to　10,000　h,　the　shape　of　gamma　＇　precipitates　gradually　changes　from　cuboidal　to　sphere-like.　X-ray　diffraction　experiments　reveal　that　the　constrained　gamma/gamma　＇　lattice　misfits　of　M4706　fall　into　the　range　of　-0.226%　to　-0.223%　between　800　and　850　degrees　C,　whereas　the　value　is　-0.529%　at　1050　degrees　C.　Based　on　the　experimental　results,　the　morphological　transition　of　gamma　＇　precipitates　is　discussed.　(C)　2017　Elsevier　B.V.　All　rights　reserved.