Experimental study on high-speed saw cutting of hybrid composite stacks using nanoparticle-enhanced minimum quantity lubrication

An extensive investigation into thermal stress mitigation of high-speed machining (machining speeds exceeding 3800 rpm) of hybrid composite stacks using nanoparticle-enhanced minimum quantity lubrication (MQL) is presented and discussed. Ten different interface machining conditions are examined using five different nanoparticles, namely Al2O3, 1%SWCNT, 1%MWCNT, Ni, and Al. Interface roughness measurements are recorded, and thermal stress effects are collected via digital microscopy images. Nanoparticle-enhanced MQL (NEMQL) chemical and physical properties in the form of viscosity and heat transfer capabilities are discussed in accordance with vegetable oil-based MQL. Two different vegetable oils are utilized in a 1:1 ratio to explore viscous effects in the NEMQL suspension and their respective cooling capabilities from conventional forms of machine cooling. Furthermore, the results indicate 2.5%vol Al2O3+ MQL showed the best interface roughness improvements by over 170% from the standard control dry machining of carbon fiber-reinforced polymer (CFRP) and titanium (Ti) hybrid composite stacks. Moreover, the results indicated 1%SWCNT + MQL showed the best interface roughness improvement by over 100% for CFRP and aluminum (Al) hybrid composite stacks from the standard control: dry machining. Chemical and physical properties of the NEMQL, such as thermal conductivity, viscosity, and convective heat transfer capabilities, explain to some extent the results depending on the hybrid composite stack application. The results of this experiment provide insight that NEMQL is a promising cooling lubrication method for conventional manufacturing processes in a wide array of industrial applications. The results of this study are expected to open new possibilities for eco-friendly and cost-effective methods for a high-speed cold saw cutting in advanced engineering materials.