Pengaruh Perbedaan Material Daur Ulang Alumunium Terhadap Hasil Coran Pada Pembuatan Piston Dengan Cetakan Pasir

Abstract This study aims to determine the effect of differences in aluminum recycled material on shrinkage, hardness, porosity, density, and microstructure of casting products with different aluminum materials. The test is testing chemical composition with ASTM E-1251 standard, testing microstructure with ASTM E3 standard, and testing hardness with ASTM E18-15 standard. The test results of the largest shrinkage value in the engine block material is 1.08%, followed by piston material 0.99%, and the smallest shrinkage in the material is 0.87%. At the density value obtained the largest density value on the engine block material is 2.62 g/cm3, then the piston is 2.43 g/cm3, and the crushed value is 2,23 g/cm3. In testing the chemical composition of the engine block contains 84.94% Al elements and 10.27% Si elements, the piston contains 85.67% Al elements and 11.22% Si elements, and the trace contains 89.13% Al elements and 7,8% Si elements. In the hardness test using rockwell hardness test, the highest hardness value was obtained on the engine block with a value of 56.5 HRB, followed by a piston of 30.2 HRB, and the smallest value was 13.7 HRB in stroke. From micro photo testing the results of the biggest hardness were found in the increasingly tightly arranged elements. The difference in the hardness of differences in used material from Al elements and their alloys, so that it affects the depreciation value. The greater the value of depreciation, the greater the value of its density. Keywords : Cast Aluminum, Aluminum Recyclin