Abstract: Non-ferromagnetic metal materials are widely used in aerospace,shipbuilding,chemical industry and other fields due to their strong corrosion resistance and high strength. A magnetic detection technique was proposed to realize the non-destructive testing of crack defects in non-ferromagnetic metal materials. The self-developed magnetic testing equipment was used to carry out testing and research on aluminum alloy specimens and superalloy specimens,and the magnetic induction intensity signal was collected and analyzed. The results showed that the detection signal of the magnetic detection technology would show abnormal signal characteristics when detecting surface opening defects and closure defects of aluminum alloys and superalloys,and the change amount of abnormal signal was correlated with the size and buried depth of the defect at the same time,and the depth or burial depth of the defect could be quantitatively analyzed by linear fitting. The proposed magnetic detection technology could be used for the rapid detection of cracks in non-ferromagnetic metal materials,and had high reliability and effectiveness,which provided a new idea for the quantitative detection of non-ferromagnetic metal materials.

Key words: non-ferromagnetic metals, cracks, magnetic detection technology, magnetic induction strength