Fabrication of very-high-strength pure copper with fine grain structure through multi-axial diagonal forging

•Very-high-strength pure Cu is successfully fabricated by the MADF process.•The 1-cycle MADFed pure Cu has a TYS of 397 MPa and UTS of 436 MPa.•The average grain size in the center region reduces to 0.8 μm after 4 MADF cycles.•Microstructural homogeneity increases linearly with increasing MADF cycle number.