FIBER-REINFORCED COMPOSITE WORKPIECE SURFACE QUALITY IMPROVEMENT IN MACHINING BY MILLING-CUTTERWITH OPPOSITE CUTTING EDGES USING SPH-METHOD SIMULATION
Unidirectional fiber-reinforced composite workpieces are often machined in practice. During such cutting process stronger fibers are bended more than weaker matrix and an interfacial debonding between them is occurred under machined surface. It deteriorates working properties of composite and so debonding reduction is a vital technological problem. One of the perspective ways to diminish such debonding is to substitute the orthogonal cutting by the oblique one. This decision is confirmed by known practice of milling cutter design. Milling cutters with the continuous helix edges and with interrupted ones with a large tool cutting edge angle are often used. In this case fiber deformations in a cutting zone are significant. To diminish such deformations the hypothesis about efficient use of opposite cutting edges location with a large tool cutting edge inclination is assumed. This hypothesis is checked by using of SPH method with micro-simulation of cutting of metal-matrix composites (steel fibers and aluminum alloy matrix). Johnson-Cook approach is used for both materials. Obtained qualitative deformation pictures confirm this hypothesis. On this basis a new milling cutter design with tool major cutting edges located as a chevron on a cylindrical surface with alternate arrangement is suggested. Computer simulation of such edges operation shows minimal fibers deformations in cutting zone. At the same time, undesired excessive chip packing in a zone between the adjacent cutting edges is not observed. The obtained results are preliminary considering the limited computer model size and no experiment verification made.