Achieving high quality surface of laminated glass-reinforced plastics during milling

Abstract

Milling is one of the most common ways of workpiece machining, but obtaining a high quality surface of laminated composite materials is difficult due to their layered structure, high strength characteristics and low heat conductivity. This poses a problem of creating a milling technology that provides a high quality surface. This research investigates STEF -1 glass-fiber plastic with fine grain structure processed on the equipment with high cutting speed. The object of the research is roughness Ra as a quality criterion. Our glass-fiber plastic milling experiments demonstrate that the surface quality depends to a large extent on the cutting modes and the wear level of the tool cutting edge which is determined by the size of the wear bevel on the flank surface. The blade of the cutting tool is established to wear unevenly during glass-fiber plastic processing as it interacts with two different materials. We recommend the wear bevel on the flank surface to be less than 0.35 mm to ensure the high quality of the laminated composite material surface. The cutting modes should be within the following range: feed per tooth is 0.15 ÷ 0.17 mm/tooth, cutting depth is 0.5 ÷ 0.9 mm, cutting speed is above 45 m/s, with the cutting part of the tool being made of high-strength instrumental materials.