Design for additive manufacturing (DfAM) of hot stamping dies with improved cooling performance under cyclic loading conditions

Additive Manufacturing (AM) provides almost infinite design flexibility enabling the fabrication of intricate components. This study proposes a Design for AM (DfAM) method for hot stamping dies which exploits the benefit of lattice structures' reduced thermal conductivity. The term effective cooling area of a cooling channel is introduced and is used for lattice structure integration into a hot stamping die. Four hot stamping dies with 4 different effective cooling areas were AMed using selective laser melting and subsequently tested in the hot stamping of AA7075 aluminum alloy blanks under cyclic loading conditions. Temperature evolutions, for both the blank and die, are presented with associated computed cooling rates. The analysis of the results shows that the proposed lattice structure AMed stamping dies significantly improve the cooling performance of a hot stamping die with printing times reduced by at least 12% compared to traditionally manufactured AM dies.