ANALISIS KEKASARAN PERMUKAAN PADA PROSES SIDE MILLING MATERIAL BERDINDING TIPIS (THIN WALLED) ALUMINIUM 7075
Daftar Isi:
- Machining the structural components of an aircraft involves several parts of the skeleton and thin-walled flanges. These thin-walled parts are considered the design to meet the strength and weight needed. The united thin walled parts have outstanding advantages including high rigidity and lightness. Aircraft bodies and aircraft wings consist of a number of thin walls to meet these requirements. Plate thickness is more than 6.35 mm, sheet less than 6.35 mm, and thin wall around 1 mm to 2.5 mm. The machining of a thin wall requires a machining process using a milling machine, where the workpiece is diffused using an endmill tool. Therefore, the surface roughness of the refining results must be considered in order to obtain a low level of surface roughness. These components must be made as smooth as possible because it will affect the wind friction on the aircraft's body. Many factors influence the level of surface roughness of an object produced by a CNC milling machine starting from the cutting condition, which is meant by cutting conditions are the amount of cutting speed, thickness of feeding, depth of cut, machine condition and workpiece material. In this study workpieces with dimensions of 3 mm x 50 mm x 100 mm were carried out by machining side millings on the sides of the workpiece. Cutting was done 30 times with different parameters according to Table 3.3 without using cutting fluid. After completing the machining process, then further surface roughness testing is carried out. The high value of surface roughness is caused by the size of the feeding motion and the depth of axial cutting. The cutting rate and depth of radial cutting do not significantly influence the increase in surface roughness value. Based on the test results showed that the highest surface roughness value was shown in the 13th test of 4.42 μm with variations in the test variable Vc of 80 m / minute, fz of 0.05 mm / tooth, the depth of the cut of aradial was 0.4 mm and the depth of cut aaxial of 10 mm. While the lowest surface roughness value is shown in the 19th test with a surface roughness value of 0.86 μm with a variation of the Vc test variable of 102.5 m / minute, fz of 0.025 mm / tooth, the depth of the aradial cut is 0.3 mm and the depth of aaxial cut by 7.5 mm. This is caused by factors that influence the value of surface roughness such as cutting