连续柱状晶纯铜的断裂分析.pdfVIP

··2007.10 M-14 100083 [ ] EBSD EBSD [100] [] [TITLE] The fracture analysis of the copper with continuous columnar crystals [ABSTRCT] The pure copper bar with continuous columnar crystals, which had excellent plastic workability and conductivity, was fabricated by continuous unidirectional solidification process with vacuum melting and argon protecting. In this paper, the fracture process of the pure copper bars with continuous columnar crystal was analyzed by in-situ tensile observation in SEM. It was found that the fracture surface was upright to tension orientation. Slips in deformation zone were uniform, with corrugation slip bands. The pattern of fracture zone looked like a multangular cup which was the typical characteristic of the structure with continuous columnar crystals. There were many equiaxed dimples in the region of fracture which indicated good abilities in plastic deformation. The result of EBSD indicates that in this material the major direction of crystallization is [100], and grain boundaries are low-angle grain-boundaries. SEM in-situ tensile test shows that some slip lines propagated across gain boundaries and did not change their directions between adjacent grains of less orientation difference, when deformation is becoming higher, there is more slip-systems grain and they make distinct stress concentration. [KEY WORDS] fracture analysis, dimples, continuous columnar crystals, slip system