In this research, the heat transfer model of surface grinding temperature field with nanoparticle jet flow of MQL as well as the proportionality coefficient model of energy input workpiece was established, respectively. The numerical simulation of surface grinding temperature field of three workpiece materials was conducted. The results present that, in the workpiece, the surface temperature was significantly higher than the subsurface temperature, presenting relatively large temperature gradient along the direction of workpiece thickness. The impact of the grinding depth on grinding temperature was significant. With the increase of the cut depth, peak values of the grinding temperature rocketed. Distribution rules of the temperature field of 2Cr13 in four cooling and lubrication approaches were the same. Based on the excellent heat transfer property of nanofluids, the output heat through the grinding medium acquired an increasingly high proportion, leading to the drop of the temperature in the grinding zone. For the same cooling and lubrication conditions, grinding temperature presented insignificant changes along the direction of grinding width. Yet, under different cooling conditions, the temperature variation was significant. MQL grinding conditions with additive nanoparticles demonstrated great impact on the weakening of temperature effect on the grinding zone.

Solid nanoparticles were added in minimum quantity lubrication (MQL) fluid medium to make nanofluids, that is, after the mixing and atomization of nanoparticle, lubricants and high pressure gas, to inject solid nanoparticle in the grinding zone with the form of jet flow. The mathematical model of two-phase flow pressure field of grinding zone with nanoparticle jet flow of MQL was established, and the simulation study was conducted. The results show that pressures in the grinding zone increased with the acceleration of grinding wheel, sharply decreased with the increased minimum clearance, and increased with the acceleration of jet flow. At three spraying angles of nozzles, when the nozzle angle was 15 ∘ , the pressure of grinding zone along the speed of grinding wheel was larger than the rest two angles. On the experimental platform built by KP-36 precision grinder and nanoparticle jet flow feed way, CY3018 pressure sensor was used to test the regularities of pressure field variations. The impact of the speed of grinding wheel, the gap between workpiece and grinding wheel, jet flow velocity, and spraying angles of nozzles on the pressure field of grinding zone was explored. The experimental result was generally consistent with the theoretical simulation, which verified the accuracy of the theoretical analysis.

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