Higher harmonic analysis of ultrasonic signal for ageing behaviour study of C-250 grade maraging steel

Nonlinear ultrasonic techniques for nondestructive assessment of micro damage in material: A review

“…Besides of fatigue damage, other failure mechanisms such as hardening, 30 thermal aging, [31][32][33] and corrosion have been studied for the nonlinear ultrasonics to be applied. Hurley 30 investigated the correlation of nonlinear ultrasonic characteristics with precipitate-hardening in ASTM A710 steel containing copper-rich precipitates.…”

“…In recent, more systematic approach has been made to study the precipitation kinetics of maraging steel using higher harmonic analysis. 33 Also reported in literature are creep assisted microstructure variations in CrMoV rotor steels. 3 CrMoV steel samples were heattreated and fracture appearance transition temperature (FATT) was determined as a function of aging time for calculating fracture toughness.…”

Creep degradation characterization of titanium alloy using nonlinear ultrasonic technique

“…Therefore, it is of increasing importance to establish an effective non-destructive characterization method of creep degradation at early stage for structural health monitoring (SHM). In recent years, it is noted that nonlinear ultrasonic technique, using the amplitude ratio of primary frequency to higher harmonic frequencies, has been found to be considerably sensitive to microstructure evolution of materials [5][6][7][8][9][10][11][12][13][14][15].…”

“…Walker et al [7] used nonlinear Rayleigh waves to characterize the plastic deformation in A36 steel specimens, and the results show an increase in the measured acoustic nonlinearity, which indicates that the acoustic nonlinearity for A36 steel is highly dependent on plastic deformation. Recently, Metya et al [8] applied higher order harmonic to study the ageing behavior of C-250 grade maraging steel, whose results showed that the nonlinear parameter β increases with the formation of finer precipitates at the initial stage of ageing and then decreases at longer ageing time due to the coarsening of precipitates. Baby et al [4] conducted experimental measurements of the higher order harmonics in titanium alloy in order to evaluate their creep damages.…”

“…These events will cause losses of coherency and material strength, and then give rise to a formation of micro-voids. All these microstructure evolution during creep loading process would produce a very clear nonlinear response in materials [4,[8][9][10]. Though recently some investigations have been made to study thermal ageing behavior in various heat-resistant alloys using nonlinear ultrasonic, there is a lack of information with respect to systematic work and analysis on precipitation kinetics study of creep damage in complex titanium alloy.…”