High strength and high conductivity (HSHC) Cu alloys are widely used in many fields, such as high-speed electric railway contact wires and integrated circuit lead frames. Pure Cu is well known to have excellent electrical conductivity but rather low strength. The main concern of HSHC Cu alloys is how to strengthen the alloy efficiently. However, when the Cu alloys are strengthened by a certain method, their electrical conductivity will inevitably decrease to a certain extent. This review introduces the strengthening methods of HSHC Cu alloys. Then the research progress of some typical HSHC Cu alloys such as Cu-Cr-Zr, Cu-Ni-Si, Cu-Ag, Cu-Mg is reviewed according to different alloy systems. Finally, the development trend of HSHC Cu alloys is forecasted. It is pointed out that precipitation and micro-alloying are effective ways to improve the performance of HSHC Cu alloys. At the same time, the production of HSHC Cu alloys also needs to comply with the large-scale, low-cost development trend of industrialization in the future.

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Cu–Co–Si alloys are being intensively studied as alternative candidates for Cu–Ni–Si alloys for integrated circuit lead frames. However, the effects of different precipitate types on the comprehensive properties of Cu–Co–Si alloys are not clear. Herein, several Cu–Co–Si alloys with various precipitates (CoSi, Co2Si, and Co) are designed based on phase diagrams calculation. The designed alloys are melted, cold‐rolled, and aged to test the corresponding hardness and electrical conductivity (EC). X‐ray diffraction and transmission electron microscopy are utilized to analyze the precipitates generated in those alloys. In the alloys with Co/Si ≤ 1, the excess Si atoms are not easy to precipitate from the copper lattice after CoSi precipitation, which seriously damages the EC. Co‐precipitation in alloys with Co/Si > 2 is beneficial to improve EC without sacrificing hardness. According to thermodynamic calculation, precipitates in Cu‐1.62Co‐0.35Si (wt%) alloy with total elements between 1.5 and 2.0 wt% are all Co2Si and have the highest mass fraction in the equilibrium state. The different precipitates are highly dependent on the Co/Si atomic ratio and essential to Cu–Co–Si alloys’ mechanical and electrical performances.