Surface finishing of intricate metal mould structures by large-area electron beam irradiation

► Intricate metal mould structures have been polished by the large-area electron beam irradiation technique. ► Such delicate surface structures could not otherwise be polished by alternative, conventional methods. ► A mean Ra feature surface roughness of 22 nm is achievable by this process. ► High aspect-ratio columns as well as recessed features can be successfully polished. ► A unique domed morphology on tops of columns is observed with implications for mould releasability and improved part form.