Oil-free water-based cutting fluid

Abstract

An oil-free water-based cutting fluid is disclosed. The cutting fluid comprises water, hexagonal boron nitride (hBN) particles, a dispersant, and a corrosion inhibitor. The hexagonal boron nitride (hBN) particles are hydrophilic particles having wettability in water. The hexagonal boron nitride (hBN) particle exhibits hydrophilicity solely through a heat-treatment synthesis process. The hexagonal boron nitride (hBN) particle exhibits hydrophilicity through dry surface treatment.

1 . An oil-free water-based cutting fluid comprising:
 water;   a hexagonal boron nitride (hBN) particle;   a dispersant; and   a corrosion inhibitor,   wherein the hexagonal boron nitride (hBN) particle is a hydrophilic particle that is wettable with water.   
     
     
         2 . The oil-free water-based cutting fluid of  claim 1 , wherein the hexagonal boron nitride (hBN) particle exhibits hydrophilicity solely through a heat-treatment synthesis process. 
     
     
         3 . The oil-free water-based cutting fluid of  claim 1 , wherein the hexagonal boron nitride (hBN) particle exhibits hydrophilicity through dry surface treatment. 
     
     
         4 . The oil-free water-based cutting fluid of  claim 1 , wherein the hexagonal boron nitride (hBN) particle has a primary particle size D50 in the range of 30 nm to 3 μm and a primary particle size D90 of 5 μm or less. 
     
     
         5 . The oil-free water-based cutting fluid of  claim 1 , wherein the hexagonal boron nitride (hBN) particle is mixed in an amount of 0.1 parts by weight or less relative to 100 parts by weight of the water. 
     
     
         6 . The oil-free water-based cutting fluid of  claim 1 , wherein the dispersant comprises one or more selected from the group consisting of an anionic dispersant, a cationic dispersant, a zwitterionic dispersant, and a nonionic dispersant, used alone or in combination. 
     
     
         7 . The oil-free water-based cutting fluid of  claim 1 , further comprising one or more selected from the group consisting of a pH regulator, a defoaming agent, a preservative, an antifreezing agent, and a wetting agent. 
     
     
         8 . The oil-free water-based cutting fluid of  claim 1 , further comprising one or more selected from the group consisting of Al 2 O 3 , MoS 2 , SiO 2 , ZrO 2 , CuO, SiC, TiO 2 , WS 2 , diamond powder, CNT, graphene, and graphite,
 wherein the Al 2 O 3 , MoS 2 , SiO 2 , ZrO 2 , CuO, SiC, TiO 2 , WS 2 , and diamond powder have a primary particle size D50 of 3 μm or less.   
     
     
         9 . The oil-free water-based cutting fluid of  claim 1 , wherein the cutting fluid is used in an MQL spraying method.