Tran Minh Duc¹, Tran The Long^1,, Pham Quang Dong¹, Tran Bao Ngoc¹

Recently, hard milling has attained much attention of researchers and manufacturers and increasingly applied in manufacturing engineering. In real-world manufacturing, there are a number of applications where hard milling is seen as the alternative to some of grinding operations, or these two processes complement each other. Due to enormous amount of heat generated from hard machining, the application of flood coolant could not be done or brings out little effectiveness. Therefore, the surface quality and productivity are much reduced because the early wear occurs on the carbide tools. MQL technique ultilizing Emulsion, vegetable oils, and so forth has been studied and applied to hard milling, and it reveals the promising results. To improve MQL effectiveness and hard milling performance, this paper aims to present the Nanofluid applied to MQL. The results obtained from experiments show that the maximum cutting speeds of carbide inserts are 110 -120 m/min when using Nanofluid Al₂O₃ 0.5% for hard milling of 60Si₂Mn steel (50-52HRC). Moreover, these cutting speeds increase about 157% - 170% compared to the manufacturer’s recommended guidelines with the ensureance of tool life (110.72 minutes) and surface roughness (R_a= 0.1 – 0.30 µm; R_z= 0.5 – 2.0 µm) equivalent to finish grinding. Improving the cooling and lubricating characteristics of the MQL based fluid and hard cutting performance has observed due to the presence of Al₂O₃ nanoparticles. Accordingly, hard milling technology using normal carbide inserts with low cost will be broadened, and the use of MQL with Nanofluids in real manufacturing will fulfill the technological and economic requirements.

Hard milling, Minimum quantity lubrication (MQL), Nanofluid, Al2O3 nanoparticles, cutting speed