Ultrasonic nanocrystalline surface modification of low strength aluminum alloy: trade-off between surface integrity and production rate aiming at desired fatigue life
“…Additionally, the introduction of high-density dislocations and compressive residual stresses by USM in the surface layer can result in surface work hardening. These should play a role in strengthening surface hardness as well [43]. Figure 6 Surface hardness of untreated and USM treated alloy.…”
Low-Be copper alloys exhibit high thermal and electrical conductivities but weak strength, hardness, wear and corrosion resistances, which limit their practical applications severely. To overcome these defects, we herein systematically investigate the effects of ultrasonic surface modification on the microstructures and properties of Cu-0.2Be-1.0Co alloy. It is found that the gradient microstructures characterized by pile-ups and dents, fine grains, dense dislocations and compressive residual stresses are generated in the 171 μm thickness surface layer of the Cu-0.2Be-1.0Co alloy by ultrasonic surface modification. As a result, the surface hardness obtains a 162% enhancement, the wear rate drops from 5.03 × 10 −4 to 3.46 × 10 −4 mm 3 •N −1 •m −1 , and the electrochemical corrosion current density decreases from 3.24 to 1.92 μA/cm 2 . These results indicate that the comprehensive properties of Cu-0.2Be-1.0Co alloy can be simultaneously improved by utilizing ultrasonic surface modification.
“…Additionally, the introduction of high-density dislocations and compressive residual stresses by USM in the surface layer can result in surface work hardening. These should play a role in strengthening surface hardness as well [43]. Figure 6 Surface hardness of untreated and USM treated alloy.…”
Low-Be copper alloys exhibit high thermal and electrical conductivities but weak strength, hardness, wear and corrosion resistances, which limit their practical applications severely. To overcome these defects, we herein systematically investigate the effects of ultrasonic surface modification on the microstructures and properties of Cu-0.2Be-1.0Co alloy. It is found that the gradient microstructures characterized by pile-ups and dents, fine grains, dense dislocations and compressive residual stresses are generated in the 171 μm thickness surface layer of the Cu-0.2Be-1.0Co alloy by ultrasonic surface modification. As a result, the surface hardness obtains a 162% enhancement, the wear rate drops from 5.03 × 10 −4 to 3.46 × 10 −4 mm 3 •N −1 •m −1 , and the electrochemical corrosion current density decreases from 3.24 to 1.92 μA/cm 2 . These results indicate that the comprehensive properties of Cu-0.2Be-1.0Co alloy can be simultaneously improved by utilizing ultrasonic surface modification.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
