Porosity is one of the significant defects in casting. Porosity can be controlled by adjusting casting modulus and pouring temperature. This study is aimed at to optimize casting modulus and optimization of pouring temperature. Casting modulus and pouring temperature are independent variables in this study, while the dependent variables are hardness and microstructure. This study used alloy Al-10Si that was melted on an induction furnace I.706. The results showed the highest hardness value of 130.26 HV obtained in Al-10Si alloy with casting modulus of 6.42 mm at a pouring temperature of 680°C, while the lowest hardness of 74.85 HV was obtained at 780°C pouring temperature with casting modulus of 6.012 mm. In microstructure that was formed, there were found many visible dendrite structures in aluminum solution.

casting modulus, pouring temperature, microstructure and hardness.