Repairing crack in Cu-Cr-Zr alloy towards forging mechanical properties via friction stir processing and aging treatment

作者：Zeyu Zhang, Long Wan, Qi Wen, Feng Zhang, Youlong Shi · 发表于：Materials & Design · 年份：2025 · DOI：10.1016/j.matdes.2025.114286 · 被引用次数：4 · 研究领域：Advanced Welding Techniques Analysis、Aluminum Alloys Composites Properties、Aluminum Alloy Microstructure Properties

As an essential part of continuous casting, Cu-Cr-Zr alloy molds are susceptible to cracking due to molten steel erosion, stress corrosion, and fatigue failure caused by high-temperature gradient, posing significant challenges to repair efforts. Here, Cu-Cr-Zr alloy plates with 2 mm in-depth and 1 mm in-width cracks were repaired via friction stir processing (FSP) and aging treatment. Dense and homogeneous microstructure and ultrafine grains with an average grain size of 0.55 μ m of the repaired zone (RZ) allowed for strong grain refinement against the coarse grains in base metal (BM). The nanoscale coherent precipitates induced by aging treatment exhibited precipitation strengthening, compensating for the loss of mechanical properties due to precipitate dissolution and coarsening during FSP. The microhardness, ultimate tensile strength, and the wear rate of the FSP + aged RZ were 146 HV, 456 MPa, and 5.81 mm 3 N −1 m −1 , respectively, closely reaching the mechanical properties of the BM. This work provides a promising, high-efficiency, and economical procedure for repairing cracks or other defects in Cu-Cr-Zr alloy.