Precipitation Process and Mechanical Properties of an Elastic Cu-Ni-Mn Alloy

A Cu-20Ni-20Mn alloy was prepared and the aging characteristic of this alloy was investigated in this paper. The experimental results showed that the strength of solution treated Cu-Ni-Mn alloy was enhanced by more than 500MPa when aged for more than 20h. Much more rapid increase of tensile strength was found in the cold rolling samples during the aging process, and the strength was much higher in the range from 1200-1600MPa. The side peaks found beside (200) X-ray diffraction peaks are believed to be corresponding to the Cu-rich and Mn/Ni-rich phase regions formed by up-hill diffusion. It is also known that this fluctuation of composition is usually described by sinusoidal wave, the wave length of which is estimated to be 10-15nm.