| The microstructure and mechanical properties of as-cast Ni-Pt binary alloys were studied by optical microscopy, X-ray diffraction(XRD) quantitative and qualitative analysis, micro-hardness testing. The results showed that Ni -Pt binary alloy is composed of NiPt single phase solid solution, the solid solution is substitutional solutes. Solid solution strengthening effect is caused by lattice distortion which induced by Pt atoms dissolve into Ni lattices. Each of interplanar spacing d is a linear increasing trend with the content of Pt. And also, the micro-hardness of the alloy increases when Pt content raises, which meets the following mathematical expressions: Hv=2.10×Pt%+85.04. Columnar crystal of as-cast organization changes into isometric and dendrites with the increase of the content of platinum and the grain size is refined. When the mass fraction of Pt reaches 60%, the as-cast organization is characterized by plentiful dendrites, and there are the casting cracks. |
