Effect of Sintering on the Properties of gamma -Brass (Cu sub(5)Zn sub(8)) Nanoparticles Produced by the Electric Arc Discharge Method and the Thermal Conductivity of gamma -Brass Oil-Based Nanofluid

Cu sub(5)Zn sub(8) nanoparticles with a mean particle size of 21 nm were produced using the electric arc discharge method at 1 atm pressure Ar and 300 A arc current. The effect of sintering on the properties of Cu sub(5)Zn sub(8) nanoparticle pellets prepared by pressing nanopowders under 750 MPa pressure was studied. Particles grew uniformly when sintered at 1013 K (740 degree C), as opposed to those samples that were unsintered, resulting in a reduction of pores and an increase in density of about 21 pct. The electrical resistivity and hardness of the samples were also highly reduced. The results showed that the cooling rate can affect the properties of the sintered samples. The oil-based nanofluids with 0.2 to 3 wt pct of Cu sub(5)Zn sub(8) nanoparticles were prepared, and it was found that the thermal conductivity of nanofluids increased with an increase in the weight percent of nanoparticles up to 1 pct and decreased afterward. The highest increase in thermal conductivity of 6 pct was measured compared to the base fluid.