**2. Experimental**

The chemical composition of the A357 aluminum casting alloy studied within the scope of the study is given in **Table 1** (Quantolux QLX3). Ten cylindrical bars were produced and cast into a sand mold where the dimension of bars was Ø8 by 160 mm (**Figure 1**). The weight of the charge to be melted was measured (approximately 15 kg) and melted in an ICS induction furnace in an A50 SiC crucible at 750°C. Reduced


**Table 1.**

*Optical emission spectrometer analysis.*

**Figure 1.** *Molds used for the characterization tests (a) fluidity (b) tensile bars.*

pressure test samples were collected for measuring the melt cleanliness level. Ceramic diffusor lance was used where nitrogen gas was purged through the melt for the cleaning process.

The master alloys added to the melt were Al3Er, Al2Sc, Al5V and Al10Y. The weight % was aimed to achieve 0.05 and 0.1 in the alloy. Sand molds were prepared for the characterization tests. Octopus mold design [27] (**Figure 1a**) was used for fluidity characteristic where each arm had a length of 500 mm with thickness varying from 0.2 to 8 mm. Ten tensile bars were produced for each parameter where 10 mm diameter and 180 mm length cylinders were produced (**Figure 1b**). The molds were placed next to each other and after tensile bars were cast, the fluidity test mold was filled. This was repeated twice, and the same procedure was followed for each parameter to be able to have the same condition for each casting trial.

After the castings were complete, the samples were subjected to a heat treatment procedure [28] where the solutionizing was carried out at 540°C for 6 hours. The samples were then quenched in water (80°C) followed by 4 hours of aging at 145°C. Samples were machined according to ASTM E8/E8M standard and tensile tests were carried in Zwick Roell 8596. Weibull analysis was used to plot the survivability of the alloys studied in this work.
