Experimental investigation on the quality of holes in the multi-layered GFRP-titanium obtained in drilling operations
Abstract
Experimental investigation on the quality of holes in the multi-layered GFRP-titanium obtained in drilling operations
Incoming article date: 04.08.2015The purpose of this work was to study the influence of the structural and geometric parameters of the twist drill on the quality of the processed hole and productivity of machining the high strength polymeric composite material – glass fiber epoxy-based plastics that are reinforced by titanium foil. In the structure of high loaded polymeric composite parts the reinforcing layers made from the titanium foil are used. These titanium layers are placed between layers of the winding unidirectional glass fiber tape or the carbon fiber tape. In order to reach the required dimensional accuracy, the macro- and micro geometry of the hole surfaces, to eliminate the overheat, burning, and delaminations of material, need to use sharp-edged tools, which wear out quickly, and remove the drill from the workpiece at frequent intervals to clean the chips from the flutes of the drill and the hole being drilled. We studied the drilling of glass fiber reinforced laminates at the different schemes of sharpening the drills made from the high-speed steel. We present some experimental results of the optimal feed and speed for the studied twist drills, the dependencies of the highness parameters of roughness, and also characters and degree of delamination at starting and finishing hole for the different tools, feed and cutting speed.
Keywords: GFRP, drilling GFRP, delaminations, double-angle sharpening