Substructure and Microhardness Correlation of Polycrystalline Copper Plastically Deformed in Tension, Compression and Solid Particle Erosion Modes

摘要

Solid particle erosion data and the mechanics of the impact process have been reported for many materials. However, relatively little effort has been devoted to the evaluation of the erosion induced microstructural changes that occurred in the subsurface region. In particular, the erosion induced plastic deformation results in a strain hardening gradient that rapidly decreases with distance from the eroded surface. For the case of pure polycrystalline copper eroded at room temperature with alumina particles at four different conditions, the erosion damage gradient was determined indirectly by means of microhardness measurements and also through direct observations of the dislocation microstructure by transmission electron microscopy (TEM). Two particle velocities, 20 and 60 m/s, were considered at both 20 and 90 degree attack angles. The microhardness and TEM information obtained from the erosion specimens were then compared with similar data obtained from uniaxial tension and compression specimens tested to different true strain levels between the yield strength and the ultimate tensile strength. Both the tensile and the compressive shear flow stress levels (tau) were found to be related to the mean dislocation cell diameter (d) by the equation tau = 11.5Gbd exp -1 where G is the shear modulus and b the Burgers vector. 8 figs. (ERA citation 10:025797)