阳极电流对纯铜裂尖表面形变和总体形变影响的对比

采用微机控制激光散斑干涉技术，对多晶纯铜平板预裂纹试样在空气及在３．５％ＮａＣｌ溶液中外加阳极电流条件下的裂纹张开位移进行了原位测量，并对比了这两种条件下，裂尖表面应变场的变化，研究了阳极溶解对裂尖材料总体形变和表面形变的影响。结果表明：加阳极电流后，裂尖表面应变量和应变范围都明显增大，而反映裂尖总体形变的张开位移变化很小。阳极溶解对金属内部材料的形变没有直接的影响，只能缓解金属表面的变形硬化，促进金属的表面变形．

SURFACE AND BULK DEFORMATION NEAR CRACK TIP FOR PURE COPPER UNDER APPLIED ANODIC CURRENT

The SPI technique was used to investigate the bulk deformation at crack tip in CF process by comparing the crack tip opening displacement(CTOD)of pure copper speci mens in air and in 3.5%NaCl solution with an applied anodic current of 20 mA / cm2.In order to study the difference of anodic current influences on the bulk deformation from and the surface deformation of crack tip,comparative analysis has been carried out by measuring the variations of the surface strain distribution under the same conditions.The experimental results showed that, after applying anodic current,both the plastic zone size and the strain value on the surface near crack tip increased significantly, however, the crack tip opening displacement which reflects the bulk deformation of crack tip only increased a little. It has been shown that the anodic current has no direct influence on internal material at crack tip, but can relieve the surface strain hardening and enhances the crack tip surface deformation significantly.