2014 年 80 巻 11 号 p. 1018-1022
It has been well known that molded defects of injection molding due to exhausting air from cavity can be reduced by permeable metal consisting of micro-structure. In this study, it is focused on that the micro-structure of injection mold is made from powder metal, and is manufactured by the Metal Laser Sintering with High Speed Milling in technology field of additives manufacturing. This paper deals with fabrication method for the structure with air permeability and evaluation for its properties. The first, we proposed a laser scanning path strategy which reduces fabrication defects. This strategy utilizes change of powder metal thermal conductivity which varied before and after sintering. The second, by using the strategy, a structure which consists of straight gas-exhausting tubes like a regular lattice with cubic elements is fabricated. Through fundamental experiments, the structure provides more amount of exhausted-gas and makes the amount have less variance. We confirmed the effectiveness of the proposed strategy, and identified a permeability coefficient of fabricated structure by experiments. The coefficient is expected to be incorporated in the mold design process.
