Статья

Improving the weldability and mechanical property of ultrasonic spot welding of Cu sheets through a surface gradient structure

Zenglei NiSchool of Materials Science and Engineering, North China University of Water Resources and Electric Power, Zhengzhou 450045, ChinaJ.S. MaSchool of Materials Science and Engineering, North China University of Water Resources and Electric Power, Zhengzhou 450045, ChinaА. А. НазаровInstitute for Metals Superplasticity Problems, Russian Academy of Sciences, 39 Khalturin st., Ufa 450001, RussiaZhipeng YuanSchool of Materials Science and Engineering, North China University of Water Resources and Electric Power, Zhengzhou 450045, ChinaX.X. WangSchool of Materials Science and Engineering, North China University of Water Resources and Electric Power, Zhengzhou 450045, ChinaSansan AoSchool of Materials Science & Engineering, Tianjin University, Tianjin 300072, ChinaHongjun JiThe State Key Laboratory of Advanced Welding and Joining, School of Materials Science and Engineering, Harbin Institute of Technology at Shenzhen, Shenzhen 518055, ChinaPeng GuoState Key Laboratory of Advanced Brazing Filler Metals and Technology, China Academy of Machinery Zhengzhou Research Institute of Mechanical Engineering Co., Ltd., Zhengzhou, ChinaJian QinState Key Laboratory of Advanced Brazing Filler Metals and Technology, China Academy of Machinery Zhengzhou Research Institute of Mechanical Engineering Co., Ltd., Zhengzhou, China

2025en

ABI

Аннотация

The weldability of metal sheets decreases with the increase of thickness during ultrasonic spot welding. To enhance the weldability and mechanical strength of ultrasonic spot welding of original Cu (O–Cu) sheets, a surface gradient structure (SG-Cu) was designed. The optimized SG-Cu sheets exhibited a 6 μm-thick nanocrystalline layer with an average grain size of 780 nm near the surface, accompanied by a substantial reduction in friction coefficient. Microstructural characterization showed that the improved metallurgical bonding originated from discontinuous dynamic recrystallization at the welded interface, which produced randomly oriented fine equiaxed grains with active grain boundary migration. The welding interface temperature, lap shear stress and fracture work of the SG-Cu/SG-Cu joint were enhanced significantly in comparison with the O–Cu/O–Cu joint. Notably, the surface gradient structure fundamentally altered the fracture mechanisms - replacing the characteristic cleavage planes and tear ridges of O–Cu/O–Cu joints with the densely distributed micro-dimples in SG-Cu/SG-Cu joints.

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Идентификаторы

DOI: 10.1016/j.jmrt.2025.03.301

Цитирования и источники

Цитирований: 3Использованных источников: 0

Показатели — AkademScholar