Effect of Mn content on microstructure and properties of as-cast Cu-Ni-Cr alloy
Cu-Ni-Cr-xMn(x=0,1,3,5,7 and 9 mass％)alloys were prepared by atmospheric melting,and the effect of Mn content on microstructure and properties of as-cast Cu-Ni-Cr-xMn alloys was studied by means of optical microscope,scanning electron microscopy,X-ray diffractometer and electronic universal testing machine.The results show that the microstructure of the as-cast Cu-Ni-Cr-xMn alloys is composed of Cu-rich phase(γ1),Ni-rich phase(γ2)and Cr-rich phase,and the addition of Mn significantly changes the segregation form of the second phase in the microstructure of the Cu-Ni-Cr-xMn alloys.The addition of Mn significantly aggregates the Cr element in the Cu-Ni-Cr-xMn alloys microstructure in the Ni-rich zone,and the Cr content in the Ni-rich zone increases significantly.As the Mn content increases,the size of nodular Ni-rich phase(γ2)and Cr-rich phase in the matrix decreases,and their distribution becomes more uniform.The existence of a large number of fine Cr-rich second phase significantly improves the mechanical properties of the alloys.When the Mn content is 3％,the small-sized Cr-rich second phase begins to segregate at the grain boundaries and form a chain like structure,which has a negative effect on the mechanical properties of the alloy.When Mn content is 7％,the effect of Mn atom solid solution strengthening and second phase refinement is significant,and the mechanical properties of the alloy are the best,with a hardness of 195.06 HB and a tensile strength of 401 MPa,respectively.
NETL
NSTL
万方数据
维普
