摘要
The residual stress is formed in YBa_(2)Cu_(3)O_(7-δ) (YBCO) bulk superconductors,which undergoes a complex fabrication process and experienced a huge temperature change about 1000℃.The residual stress may result in micro-cracks in YBCO bulks and cause degradation of its superconducting and mechanical properties.It will be greatly helpful to reform the structural designs if the distribution of residual stress in YBCO bulk can be investigated.The traditional method of measuring residual stress does not apply to oxide ceramics as they are brittle materials.In this paper,a YBCO bulk was sliced into pieces of several millimeters in height,which could thus be treated as a plane-stress problem.The residual stress and principal stress angle for YBCO bulk have been obtained by an artificial hole-drilling method with very low speed.
基金
supported by the fund of Natural Science Foundation of China(Nos.11872196,11902130).
