Effect of Sandblasting Pressure Using Silica Sand and Garnet Sand on the Surface Roughness of 6061-T6 Aluminum

Bima Arya Sena, Rizal Arifin, Rizki Dwi Ardika

Mechanical Engineering Study Program, Faculty of Engineering, Universitas Muhammadiyah Ponorogo

Ponorogo

Email: bimaaryasena172@gmail.com

ABSTRACT

This study aims to analyze the effect of variations in air pressure and abrasive media on the surface roughness characteristics of 6061-T6 aluminum, which includes surface roughness (Ra), maximum surface roughness (Rz), and the average surface roughness depth (Rsm). The abrasive media used in this experiment were silica sand and garnet sand with a mesh size of 60 mesh. The operational parameters used included nozzle pressure of 100 psi, a spraying distance of 100 mm, a spraying angle of 90°, and a spraying time of 20 seconds, with a nozzle diameter of 6 mm. The variations in air pressure tested were 2.5 bar, 3.0 bar, 3.5 bar, 4.0 bar, and 4.5 bar. The testing was conducted using a surface roughness tester to measure surface roughness, a Micro Vickers Hardness Tester to measure material hardness, and a micrometer to measure plate thickness. The results showed that an increase in air pressure significantly affected the surface roughness of 6061-T6 aluminum. At a pressure of 4.5 bar using silica sand, the highest roughness value was obtained, reaching 5.861 μm, while the highest roughness value for garnet sand was 4.5 bar, resulting in a roughness value of 4.359 μm. Meanwhile, the lowest roughness value for silica sand was obtained at a pressure of 2.5 bar, with a roughness value of 3.459 μm. In contrast, the lowest roughness value for garnet sand was obtained at a pressure of 2.5 bar, with a roughness value of 3.54 μm. The Rz value before treatment was 124.0 HV, while after treatment it increased, with the highest value reaching 116.7 HV at a pressure of 4.5 bar. Meanwhile, garnet sand reached a maximum hardness of 116.7 HV at a pressure of 4.5 bar. The analysis of the results indicates that increasing the blasting pressure tends to increase the roughness of the material, in which silica sand causes a more significant increase in surface roughness of 0.033 mm, while garnet sand causes an increase of 0.011 mm at a pressure of 4.5 bar. Thus, silica sand provides better surface roughness compared to garnet sand, resulting in a higher and more consistent level of roughness, while garnet sand produces a more even and uniform surface roughness increase at a pressure of 3.5 bar.

Keywords: Sandblasting, 6061-T6 Aluminum, Silica Sand, Garnet Sand, Air Pressure.