Determination of mechanical and wear properties of aluminum alloys in changing casting conditions

This study has examined impact of modification and grain refining processess in sand and die casting of Etial 110, Etial 140, Etial 160, Etial 177 aluminum casting alloys - (i) with no additive, (ii) with Al5Ti1B grain refiner, (iii) with both Al5Ti1B grain refiner and Al10Sr modifier - on microstructure, mechanical and wear properties. Al5Ti1B master alloy as a grain refiner to effect by 0.2% Ti in weight and Al10Sr master alloy as a grain refiner to effect by 0.2% Sr in weight has been used in the Etial 110, Etial 140, Etial 160, Etial 177 alloys. It is aimed at determining the effects of aforementioned master alloys and casting method on the microstructure, mechanical properties and wear properties of the above casting alloys. Before casting of aluminum alloys, liquid metal cleaning measurements has been controlled by Reduced Pressure Test (RPT). Microstructure investigations, Scanning Electron Microscopy (SEM) investigations, density measurements, wear and hardness tests have been applied to the samples obtained from casting experiments. According to the investigations and test results, in each alloy, it was determined that the dentritic and coarse structure formed in the microstructures due to the addition of grain thinner decays to form a finer grain structure. The addition of the modifier has caused changes in the shape and size of the Si crystals formed in the casting internal structure and it was observed that the lamellar structure of the alloys transformed into a fiber-like structure. Both grain refiner and modifier additions have had a positive effect on hardness increase. It has been determined that the wear rate is reduced by adding TiB and TiB-Sr to the alloys produced using sand and gravity mold. Finally, the highest wear rate was obtained in Etial 110 alloy produced by sand mold method, while the lowest wear rate was obtained in Etial 140-TiB-Sr alloy produced by gravity mold method.