High-strength Wear Of Cu-ni-sn Alloy Aging

The aging characteristics of high-strength and wear-resisting alloy Cu-15Ni-8Sn-0.25Mn-0.1Fe were studied by means of hardness measurement, tensile test at room temrjerature, optical microscopy, XRD, SEM and TEM. The influence of different heat treatment process on the mechanical properties and microstructure of the above alloy was analyzed. The results show that,The first, a kind of Cu-15Ni-8Sn-0.25Mn-0.1Fe alloy was prepared and the rods were formed by extrusion-on-line solution treatment-cold-drawing and proceeded by stepped aging. Then hardness of the alloy reaches HRC40, tensile strength and elongation reaches 1268Mpa and 3.6% respectively.The second, the studied alloy is a typical aging strengthening one. With the rising aging temperature or the prolongation of aging time, the hardness and strength of the alloy rises firstly then falls. Under the condition of this thesis, the strengthening mechanism of the above alloy mainly includes solution strengthening, deformation strengthening and aging strengthening.The third, during one-stage aging, under the condition of higher temperature and longer time, the rods tend to form longitudinal cracks. This is due to the coupling of inhomogeneous deformation and the brittle equilibrium phase on the boundary. However, stepped aging, which relaxes internal macro-stress under lower temperature then ages under higher temperature, can avoid longitudinal cracks effectively.