Cutting Carbon-Carbon composites by the diamond drills variable cyclic feed

Abstract

Purpose. The article presents an original solution to the actuality problem of increasing the efficiency of drilling composite materials of the carbon group with diamond drills through the use of a dynamic working feed. It is shown that the application of a cyclic low-frequency load to a diamond drill makes it possible to increase the efficiency and quality of processing without destroying the composite.Methodology. To solve the problems of determining the rational dynamic load of the drill during the operation, the approach of micro- and macroanalysis of the behavior of the processed material was used. The material itself was represented by an inhomogeneous finite medium, the properties of which are described using the concept of the initial structural element of the material.Results. Based on the analysis of the behavior of the primary structural element, the stress state of the cutting zone in carbon composite materials was estimated, and it was shown that their processing using diamond ring drills is effective and efficient. Originality. The construction of models based on the primary structural element and the establishment of patterns of crack development in an inhomogeneous medium allowed us to obtain an expression for estimating the sizes of sludge particles formed during processing and determined rational processing conditions.Practical value. The use of variable cyclic loading can significantly reduce the thickness of the destructive layer formed by the drill, as well as reduce the cutting force, especially during prolonged use. Since dust and sludge formation play an important role in drilling, further research should be aimed at establishing rational parameters of the working layer of the tool, the presence of cavities on it to remove microsludge and dust from the treatment zone.