Realising high-quality welding of the peak aged Cu–Cr–Zr alloy has always been a big challenge. Under a low rotation rate of 400 rev min⁻¹, equiaxed ultrafine grains together with nanoscale precipitates with comparable size to that of the peak aged state were obtained in the nugget zone of the friction stir welded joint. Further, the initial strengthened precipitates were also preserved near the nugget zone, neither dissolved nor coarsened. Therefore, softening zone disappeared and a high-quality weld with equal strength to the base material was first achieved. Furthermore, the electrical conductivity of the joint was hardly weakened. This study provides an effective method to improve the strength and electrical conductivity of the precipitation-hardened Cu alloy joints.

实现峰值时效Cu-Cr-Zr合金的高质量焊接一直是一个很大的挑战。在 400  rev min ^-1的低转速下，在搅拌摩擦焊接接头的熔核区获得等轴超细晶粒以及与峰值时效状态相当的纳米级析出物。此外，初始强化析出物也保留在熔核区附近，既不溶解也不粗化。因此，软化区消失，首先实现了与母材强度相等的高质量焊缝。此外，接头的导电性几乎没有减弱。该研究为提高沉淀硬化铜合金接头的强度和导电性提供了一种有效的方法。