The Effect of Concentration of Oleic Acid in Liquid Paraffin Coated on Work-Hardened Surface on Orthogonal Cutting Behaviour of Aluminums.

The coating effects of organic polarity substances on the orthogonal cutting behaviour have been investigated for as-annealed pure aluminum surface and work-hardened one. The work-hardened surface for cutting is obtained by pre-cutting to the as-annealed aluminum. The coated material on as-annealed or work-hardened surface is liquid paraffin containing 0-100mass% oleic acid as organic polarity substances. Orthogonal cutting speed is 1.67mm/s and cutting depth is 0.02mm. The following results were obtained. In work-hardened specimens, the coating of liquid paraffin containing over 0.lmass% oleic acid brings the decrease of cutting force, the improvement of cutting surface roughness and the thinning of chips. The coating effects are never observed not only for work-hardened specimens which are coated liquid paraffin containing 0-0.04mass% oleic acid but also for as-annealed specimens which are coated 0-100mass% oleic acid. Chemical interaction between molecules of oleic acid and dislocation might promote the above effects.