Microstructure and mechanical properties of nickel strengthened by Y2O3 through rock-milling and spark plasma sintering

Microstructure and mechanical properties of nickel-Y2O3 composites with content of 1 wt %, 2 wt %, 3 wt %, 5 wt % Y2O3 were prepared by rock-milling and spark plasma sintering were investigated. The obtained experimental data clearly show that the nickel with different contents of Y203 powders was evenly distributed after rock-milling 4 h with 30 Hz. Particle size analysis indicates that the grain size was fine and the average grain size was below 0.40 mu m. The nickel-2 wt. %Y2O3 shows better relative density and Brinell hardness of 92.7% and 146 HBW, respectively. The compressive strength of nickel-Y2O3 was also investigated and the specimens of nickel-1 wt. % Y2O3 and nickel-2 wt. %Y2O3 had not exhibited obviously crack or imperfections in the surface. However, specimens of nickel-3 wt. % Y2O3 and nickel-5 wt. % Y2O3 had the ultimate stress with increasing the loads, and the values were 1100 MPa and 1200 MPa, respectively. (C) 2018 Elsevier B.V. All rights reserved.