Standard mechanical tests have long guided material testing, ensuring reproducibility and comparability. Tests like tensile, shear, and bulge, analyzed by a classical approach, require standard geometries and test procedures, being limited to simple scalar outputs for global mechanical properties. However, this approach fails to capture the localized, complex responses of advanced materials that exhibit anisotropy, heterogeneity, and nonlinear responses. A paradigm shift known as Material Testing 2.0 (MT2.0) integrates advanced techniques such as full-field measurements (FFMs) and inverse identification methods to enable the characterization of localized material behavior in modern engineering materials under deformation. Despite substantial progress in metrological assessment, full-field measurements, inverse identification techniques, and good practices guidance, these developments remain only partially harmonized within existing mechanical testing standards. In particular, no widely adopted end-to-end framework currently integrates experimental design, full-field measurements, inverse identification, uncertainty assessments, parameter validation, and reporting for MT2.0-based material characterization. This work presents a review of the main classical mechanical testing standards and their limitations while introducing the concept of MT2.0. While its techniques and benefits are examined in relation to classical approaches, this work identifies the gaps between existing component-level guidance and a harmonized framework for integrating MT2.0 methodologies into standardized mechanical testing, highlighting its need for scientific and industrial communities. Establishing international standards for MT2.0 is crucial for enhanced material model calibration to support numerical simulations and product development phases.
This study investigated the effects of filler metal composition and δ-ferrite characteristics on the cryogenic behavior and corrosion resistance of 316L austenitic stainless steel (STS) welds produced by gas tungsten arc welding (GTAW) using 309L and 312 filler metals (FMs). Different δ-ferrite fractions and morphologies were observed in the weld metals (WMs), with the δ-ferrite fraction being lower in the ER309L WM than in the ER312 WM. Despite its higher δ-ferrite fraction, the ER312 WM exhibited better corrosion resistance than the ER309L WM, which was primarily attributed to its higher Cr content. The ER312 weld also exhibited higher tensile strength than the ER309L weld at both 300 and 123 K, which was associated with differences in the WM microstructure, δ-ferrite characteristics, and FM composition. All welds exhibited enhanced tensile strength at 123 K, primarily due to strain-induced martensitic transformation, while deformation twinning may also have contributed to the cryogenic deformation behavior. These findings demonstrate that the cryogenic mechanical and corrosion behaviors of 316L stainless steel welds are influenced by the combined effects of filler metal composition and δ-ferrite characteristics.
Cu–Cr–Zr alloys must combine high strength with high electrical conductivity. Reaching both at once is slow: equal channel angular pressing (ECAP) consumes many passes, and aging adds a further hour at temperature. Here a pulsed electromagnetic load was superimposed on ECAP (EMPF-ECAP) for a Cu–0.239Cr–0.126Zr alloy, and the microstructure, hardness and conductivity were compared with conventional ECAP at the same pass numbers. Four EMPF-ECAP passes raised the as-deformed hardness to 170.89 HV, above the 147.51 HV of four conventional passes. Aging at 450 °C for 0.5 h then gave a peak of 207.16 HV and 79.12%IACS. The conventional route required six passes and 1 h to reach 200.09 HV and 80.71%IACS. Electron backscatter diffraction indicates why. At a comparable grain size (8.68 against 8.99 µm), the pulsed specimens retained a lower recrystallized fraction, 20.3% against 39.4%. More of their deformation substructure survived aging, and the high-angle boundary fraction was lower, 54.7% against 81.8%. Compared with conventional ECAP, EMPF-ECAP reduced the number of passes from six to four and the aging time from 1 h to 0.5 h, reaching the same hardness in half the aging time with about 1.6%IACS lower conductivity.
Austenitic stainless steels serve as load-bearing structural materials in the divertor and vacuum vessel components of fusion devices, where they are shielded from the plasma by beryllium or tungsten. Local loss of that armour layer during off-normal events exposes the underlying steel to direct plasma contact, a condition for which surface degradation data remain limited. In this work, 08Cr16Ni11Mo3Ti (analog of 316 Ti) austenitic stainless steel was irradiated with helium plasma at 2 keV ion energy and specimen temperatures of 250, 400, and 550 °C for exposures of 500 and 5000 s. Surface degradation depended strongly on the irradiation conditions; temperature appeared to be the dominant factor, although it co-varied with the ion flux: exposure at 250 °C produced no resolvable change in surface relief, whereas grain-boundary etching appeared at 400 °C and gave way at 550 °C to pronounced preferential sputtering that exposed grains, twin boundaries, and subgrain cellular structure. Mass-loss measurements indicate removal of approximately 3.4 µm after 5000 s at 550 °C, corresponding to a mean erosion rate of ~0.7 nm/s. Microhardness increased by 30–40 HV 0.05 after 500 s at all three temperatures and remained at a similar level after 5000 s at 400 and 550 °C, whereas an unexplained decrease below the unirradiated value was found at 250 °C. The results indicate that under sustained low-energy plasma exposure, the structural integrity of the section is retained while degradation is confined to a surface layer whose properties are tailored by the balance between implantation and erosion.
Creep-life prediction and assessment of creep-strain accumulation are important for the safe operation of gas-turbine hot-section components. This study investigates a nickel-based superalloy using finite element (FE) creep analysis and the Larson–Miller parameter (LMP) method to compare stress- and strain-based damage indices. Stress-controlled cylindrical models provided FE lives for comparison with reference creep-rupture times and fitting of a stress–LMP relationship. Corresponding displacement-controlled models with matched initial stresses were used to evaluate the two indices from stress histories and accumulated equivalent creep strain (CEEQ), respectively. A stress-controlled baseline at a matched CEEQ level quantified loading-path effects on the index ratio. The approach was then applied to the first-stage rotor blade of an F-class gas turbine. Of the FE life estimates, 87.5% were within a factor of two of the reference lives; all 32 cross-validated LMP predictions were within a factor of two of the FE lives. Compared with stress control, displacement control produced stress relaxation and markedly reduced CEEQ accumulation. The relative magnitudes of the two indices varied with loading path, temperature, and stress level. The critical blade location also exhibited stress relaxation and distinct evolution of the two indices.
