TY - JOUR AU - Masnur, Dedy AU - Malau, Viktor AU - Suyitno, Suyitno PY - 2020/09/29 Y2 - 2024/03/28 TI - The dependency of the microhardnes on microstructure and solidification parameters of directionally solidified Al–4.5wt.%Cu in clay mold JF - Journal of Mechanical Engineering and Sciences JA - J. Mech. Eng. Sci. VL - 14 IS - 3 SE - Article DO - 10.15282/jmes.14.3.2020.13.0558 UR - https://journal.ump.edu.my/jmes/article/view/3189 SP - 7125 - 7131 AB - <p>Improvement of material properties is achieved by controlling parameters involved in the solidification process; therefore, understanding them and their implication are essential. This work investigated the dependency of solidification parameters (cooling rate (T<sub>R</sub>), growth rate (V<sub>L</sub>), local solidification time (t<sub>SL</sub>), temperature gradient (G)), microstructure parameters (primary (λ<sub>1</sub>) and secondary (λ<sub>2</sub>) dendrite arm spacing), and micro-hardness values (HV) of Al-4.5wt.%Cu in the clay mold. The samples were directionally solidified in Bridgman vertical apparatus and the temperature is recorded during the cooling. The solidification parameters were obtained from the cooling curve. The microstructures and micro-hardness were characterized using an optical microscope and micro-hardness tester. The microstructure parameters were measured and plotted as functions of solidification parameters using linear regression. The relation between HV and microstructure parameters are analyzed. The results show the λ<sub>1</sub> and λ<sub>2</sub> change inversely with solidification parameters except for t<sub>SL</sub>. Comparison to other works shows the exponent values of solidification parameters of the clay mold are lower than that of the carbon and stainless-steel mold. The exponent value of λ<sub>2</sub> in the clay mold is -0.183, close to the value in the graphite mold. The clay has the potential as mold material since it characteristic close to the graphite.</p> ER -