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In this work, the microstructural evolution and mechanical properties of aviation M50 steel under a novel quenching-electroshocking-tempering (Q-E-T) process were investigated. Microstructural observations indicate that the carbon concentration and volume fraction of retained austenite (RA) in Q-E-T specimens are higher than those in conventional quenching‐tempering (Q‐T) specimens due to the significant carbon partition induced by the introduced electroshocking treatment (EST). Meanwhile, the diameter of packets in the Q-E-T specimens is refined from 1.71 μm to 1.34 μm, which is attributed to the segmentation of blocky as-quenched RA by bainite transformation during EST. The mechanical analysis shows that an excellent combination of ultimate tensile strength and impact toughness is achieved for M50 steel subjected to the Q-E-T process. Compared with the conventional Q-T process, the impact absorbing energy of M50 steel is increased by 24.1% without any loss of tensile strength. Additionally, the thermal and mechanical stabilities of RA in the Q-E-T specimens are both improved. This work provides a novel strategy for improving the impact toughness of M50 by refining the microstructure and appropriately tailoring the stability of RA via an efficient Q-E-T process. [ABSTRACT FROM AUTHOR]

A novel electromagnetic shocking treatment (EST) has been put forward to optimize interface microstructure and further enhance the mechanical properties of titanium alloys. In details, tensile properties and impact toughness of TC11 titanium alloy have been investigated with room temperature tensile test and Charpy impact testing. Then, tensile fracture and impact fracture as well as microstructure including phase and interface are characterized and analyzed. The results show that after EST, the tensile strength increase slightly, the elongation decreases while the impact energy is enhanced obviously. Besides, with the maximum temperature rising on alloy sample surface being limited to just 210 °C, EST promotes the phase transformation from β to α instantly, also, wrinkling at interface is more commonly observed in EST sample, which indicates that nonlinear interface wetting and bridging are promoted by EST. It demonstrates that the increase of α mainly accounts for the slight improvement of tensile strength and the decrease of elongation. Also, considering that the phase transformation from β to α is unfavorable to the improvement of impact toughness, the degree of interface wetting and bridging which is dependent on the electromagnetic shocking energy plays a decisive role for the enhancement of impact energy of EST sample. This work provides a novel EST method to selectively embellish interface and further to improve the properties and performance of solid alloys related with interface microstructure. • EST enhances impact toughness of TC11 titanium alloy by embellishing interface. • EST induces nonlinear interface wetting and further promotes interface bridging. • EST promotes β.→α solid phase transformation instantly by interface wetting. [ABSTRACT FROM AUTHOR]