Evaluation of PCD tool performance during machining of carbon/phenolic ablative composites

Machining of polymeric composite materials is an area still full of open questions, pertaining to the assessment of machining and thermal aspects compared to metal cutting. Due to the particular nature of composite materials, precise analysis still lacks progress. In this investigation, face-turning trials were performed on carbon/phenolic ablative composites using polycrystalline diamond tools. Observations on specific cutting pressure and machining temperature revealed the existence of a critical velocity of machining. A range of machining temperature has been identified for effective machining of the composite material, beyond which tool deterioration and thereby the specific cutting pressure increases considerably. The study also enabled the determination of the effective hardness of the tool material at which steady machining can be performed.