Ultrasonic-Driven surface engineering via acoustoplasticity: From dislocation dynamics to tailored fatigue and stress corrosion cracking resistance

This review discusses acoustoplastic treatment as a modern surface engineering technique using ultrasonic vibrations to enhance the material properties including elongation-to-failure, strength, corrosion resistance, and fatigue life. The reduction of an object's resistance to plastic deformation upon subjecting it to intense mechanical vibrations at ultrasonic frequency (most often 20–40 kHz) is known as acoustoplasticity. This review covers the mechanisms of ultrasonic softening (including grain boundary growth and dislocation behavior) as well as applications of the ultrasonic-aided methods including hybrid processes, additive manufacturing, and surface processing. Process-specific outcomes are quantified for a range of materials (aluminum, steel, titanium, etc.), and they highlight future avenues for energy-efficient and scalable surface treatments. Existing constraints are also elucidated, and directions for future research and implementation of this technology are discussed.