Performance Evaluation of CNT/MoS2 Hybrid Nanofluid in Machining for Surface Roughness

Abstract

Present work is motivated by the high thermal conductivity of MWCNT and low coefficient of friction due to MoS2 nanoparticles which can significantly improve the heat transfer and lubrication performance of hybrid nanofluids than nanofluids. Hybrid nanofluids are prepared with CNT/MoS2 nanoparticles of 1wt% in sesame oil, neem oil and mahua oil by varying hybrid ratio (i.e. 1: 1; 1:2 and 2:1) and surfactant. The hybrid nanofluid composition is evaluated based on stability analysis from sedimentation and zeta potential studies. The concentration of nanoparticles is varied by preparing CNT/MoS2 hybrid nanofluid using obtained composition for stability and selected the optimal concentration for the lowest coefficient of friction obtained in friction test. The property of thermal conductivity is also evaluated for varying concentration of hybrid nanofluid at room temperature. The contact angle for CNT/MoS2 hybrid nanofluids is evaluated with a contact angle meter to understand the lubrication effect. Experimental findings for stable hybrid nanofluid are found to be sesame oil, SDS with 15% content of nanoparticle weight and 1:2 hybrid ratio. From friction test, it is observed that 2 wt%concentration is optimal for least coefficient of friction (0.038). Minimum surface roughness (Ra) is observed with 2 wt% of hybrid nanofluid compared to dry machining and conventional cutting fluid. Optimum conditions for minimum surface roughness are evaluated in turning of AISI1040 steel with the use of 2wt% of CNT/MoS2 hybrid nanofluid in RSM. Ra value is observed to decrease with an increase in cutting speed and increased with an increase in feed and depth of cut.