EFFECTIVENESS OF BIODEGRADABLE OILS AS QUENCHING MEDIA FOR COMMERCIAL ALUMINIUM

Abstract

The effectiveness of biodegradable oils such as palm oil, shea-butter oil and jatropha oil, compared to the conventional mineral oil, in the quenching of commercial aluminium was investigated. Pure commercial aluminium was solutionized in an electric furnace at (200, 250, 300 and 350) °C. The mechanical properties of the samples of commercial aluminium were determined while the cooling rate and quench severity of the oils were studied. The results showed that the quench severity of the oils is di-rectly proportional to the heat-transfer coefficient; jatropha oil, palm oil, shea butter and conventional mineral oil had heat-trans-fer coefficients of (648.80, 621.38, 447.80 and 520.72) W/m2K at the nucleation region, while their quench severities were (0.861, 0.752, 0.630, and 0.758) m-1, respectively. The hardness values of the pure commercial aluminium after quenching in jatropha oil, shea-butter oil, palm oil and mineral oil were (116.7, 121.9, 116.0 and 91.1) HVN, with tensile strengths of (96.59, 127.60, 100.86 and 84.35) MPa, respectively. Shea-butter oil and palm oil are better quenching media for pure commercial alu-minium when high ductility is required, while jatropha oil can be used when low ductility, or brittleness, is of importance.