Tensile deformation and fracture properties of seveal metallic materials, welds, and their heat-affected-zones were determined non-destructively using the Stress-Strain Microprobe (SSM) system. The system is based on automated ball indentation (ABI) technique and involves strain-controlled multile indentations at the same location on the material surface by a small spherical indenter. The technique permits evaluation of tensile deformation parameters such as yield strength, ultimate tensile strength, strength coefficient, and strain-hardening exponent, and a fracture energy parameter called indentation energy to fracture. ABI tests were conducted on carbon steels, stainless steels, nickel alloys, aluminum alloys, Zircaloys, electronic soldering materials and several nuclear pressure vessel steels (in the unirradiated, neutron irradiated, and irradiated and thermally annealed conditions). For all these test materials and conditions, the ABI-derived results wer found to agree with the data from conventional standard test methods. In addition to the laboratory applications of SSM, it can be used as an in-situ testing instrument for non-destructive assessment of deformation and fracture properties of operating structural components.
展开▼
