Effect of rotating magnetic field on NiAl(Si) phase evolution and mechanical properties of special nickel brass

Abstract

The rotating magnetic field (RMF) has been proven as one of effective method and widely used for solidification controlling of metallics materials. In this present study, a rotating magnetic field was applied during the solidification of special nickel brass, and corresponding effect on solidification microstructure and mechanical properties were investigated and revealed. Results demonstrated that the application of RMF greatly affects the lattice parameters of the synthesized NiAl(Si) phase. It also can be determined that the applied RMF can effectively eliminate the aggregation of the NiAl(Si) phase at grain boundaries, which is favorable and beneficial for homogenous distribution of NiAl(Si) phase. Additionally, the applied RMF also refines the brass matrix and induces the morphology evolution of the NiAl(Si) phase changing from bulk to spherical morphology. Accordingly, the enhanced mechanical properties with 627 MPa in ultimate tensile strength (UTS), 518 MPa in yield strength (YS) and 3.6% in elongation (EL) can be obtained under the RMF with optimal current intensity of 30 A, corresponding to the improvement of about 6.1%, 5.0% and 33.3% over the respective properties of the special nickel brass without applied RMF. In addition, underlying mechanisms for the effect of RMF on the solidification process of special nickel brass and evolution of NiAl(Si) phase, as well as the resultant mechanical properties was discussed and clarified. It is anticipated that this present study would provide a feasible and effective approach to tailor the solidification microstructure and mechanical properties of the commercial brass for industrial application.