Grain Size Effect of Bulk Nanocrystalline Pr0.5Nd0.5(Fe0.75Co0.1Cu0.01 Nb0.04Si0.05B0.05)1.93 Alloy Synthesized Under Ultrahigh Pressure

Based on the light-rare-earth anisotropic compensation system, bulk nanocrystalline Pr0.5Nd0.5(Fe0.75Co0.1Cu0.01Nb0.04 Si0.05B0.05)1.93 magnetostrictive alloys were synthesized by annealing its melt-spinning ribbons under different ultrahigh pressures. It was demonstrated that high-pressure annealing could effectively synthesize the wanted magnetostrictive phase and control the grain growth of Pr0.5Nd0.5(Fe0.75Co0.1Cu0.01Nb0.04Si0.05B0.05)1.93 bulk nanocrystals. The average grain size decreased with annealing pressure increasing from 3 to 8 GPa, accompanied by a decrease in coercivity. The volume fraction of the cubic Laves phase, as well as grain size, synergistically affected the magnetoelastic response of the investigated bulk nanocrystalline magnetostrictive alloys. This work gives us an insight into the microstructure controlling of the bulk nanocrystalline magnetostrictive materials and provides a way to select suitable bulk nanocrystals to meet the different magnetostrictive applications.