Evaluation of some Non-Edible Vegetable Oils as Lubricants for Conventional and Non-Conventional Metal Forming Processes
No Thumbnail Available
The current study focuses on evaluation of the suitability of some non-edible vegetable-based oils as lubricants for conventional metal forming operations in general and non-conventional processes such as severe plastic deformation in particular. Four non-edible oils were chemically extracted using a Soxhlet extractor and hexane solvent from mango seeds, water-melon seeds, African cherry seeds and avocado peer seeds. Comparison was made between performance of these environmentally benign oils and a mineral based SAE 40 Oleum super monograde oil in the equal channel angular extrusion (ECAE) of a cylindrical AA 6063 aluminum rod through a channel angle φ of 90o and outer angle ψ of 20o at different extrusion speed. The results show that mango oil has the best load reduction for all extrusion speeds tested, better than SAE 40, followed by avocado oil, then watermelon oil with cherry oil given the least performance. It was found, regardless of any of these oils tested, that as extrusion speed increases, there is a reduction in the load and hardness of the material tested. Comparing the unECAEed specimens with the ECAEed specimens, hardness decreases in all the ECAEed specimens tested. Further, from the hardness measurement, it was found that specimens ECAEed with vegetable-based oils probably produced better grain homogeneity than specimens ECAEed with SAE40, which perhaps account for their slightly higher hardness values. Also, although the viscosity of the SAE 40 is better than mango and avocado oils, these vegetable based oils performed excellently well when used as lubricants during equal channel angular extrusion of AA 6063 aluminum and show promising potential as alternative to mineral oil, SAE 40.
lubricants, ECAEed, unECAEed, aluminum, SPD, environmentally benign
Idegwu et al., AIP Conference Proceedings 2113, 030004 (2019)