Effect of nanoparticle volume on grinding performance of titanium alloy in cryogenic air minimum quantity lubrication

A two-step method was used to prepare alumina nanofluids with six different concentrations to perform grinding processing experiments on the titanium alloy Ti-6Al-4V. The results show that the maximum temperature in the grinding zone gradually decreases from 193.6 ℃ when the alumina volume fraction is 0.5% to a minimum value of 183.5 ℃ when it is 1.5%. When the volume fraction is further increased to 3.0%, the maximum temperature is gradually raised to 196.3 ℃. The specific grinding energy decreases from 74.8 J/mm³ to a minimum value of 64.73 J/mm³ while the volume fraction increases from 0.5% to 2.5%. When the volume fraction continues to increase to 3.0%, the specific grinding energy can rise to 69.33 J/mm³. The viscosity increases with the increase of alumina nanoparticles and reaches 235.8 MPa·s when the volume fraction is 3.0%. The contact angle decreases first with the increase of volume fraction and reaches the lowest value of 45.85° when the volume fraction is 2.5%. The dispersion of nanoparticles in the base oil affects the friction reduction and heat transfer performance of the nanofluid and thus the grinding performance.