Surface Roughness Assessment After Milling of Pure and Carbon Black Reinforced Polypropylene Materials

Abstract

Polypropylene (PP) material and its composites are preferred for many applications due to their advanced properties. Although PP material products are produced in a near-net shape, milling, which is a secondary machining process, is required to obtain dimensional tolerances, appropriate geometric shapes, and quality surfaces. For this reason, the chip removal process gains importance so that PP can be used in structural parts and assembled with different parts. In this study, milling of pure polypropylene (Pure PP) and carbon black reinforced polypropylene (CB-PP) composite investigated the effect of cutting speed (70, 100, and 130 m/min) and feed (0.4, 0.5, and 0.6 mm/rev) on the average surface roughness (Ra), chip morphology, and exit burr formation. In addition, the Ra value was predicted by mathematical modeling of the Ra. A relationship was established between the Ra and cutting parameters such as cutting speed, feed, and radial depth of cut. The experimental results showed that the Ra value decreased as the cutting speed increased and the exit burr area increased. Also, as the feed increased, the Ra value and the exit burr size increased. It was seen that the deviation of mathematical modeling from experimental results was 11% on average, and it was usable. It was observed that CB-PP gave better Ra than pure PP under the same cutting parameters.