In recent developments, the metal tube industry has witnessed significant advancements, particularly in the medical sector. Manufacturers are now focusing on refining the microstructure of metal tubes to enhance their mechanical properties, ensuring greater durability and safety for medical implants.

Medical metal tubes serve as the raw materials for various medical instruments, including cardiovascular stents, ureteral stents, and lumbar puncture needles. These implants must meet stringent performance requirements, such as non-toxicity, non-rejection by the body, strength, elasticity, corrosion resistance, and wear resistance. The mechanical properties of metal tubes have a direct impact on the safety and effectiveness of these implants.

Researchers have discovered that the passive film on the surface of metal tubes plays a crucial role in their mechanical properties. Coarse-grained materials often have a loose and open passive film, leading to poor mechanical properties. When these alloys are implanted into the human body, the blood acts as a flow electrolyte, which can accelerate the decomposition of the alloy matrix, reducing its effectiveness.

In contrast, fine-grained materials have a uniform and compact passive film, exhibiting excellent mechanical properties, low corrosion current, and a slower decomposition rate of the alloy matrix. This provides a certain level of corrosion resistance, making fine-grained metal tubes more suitable for medical applications.

To achieve this refinement in microstructure, severe plastic deformation (SPD) techniques, such as cyclic rotating bending (CRB), have been employed. These techniques significantly improve the mechanical properties of metal materials. Researchers have conducted experiments under different deformation conditions, including varying deformation temperatures, times, rotating speeds, and bending angles, to investigate the influence of these parameters on the microstructure of medical metal tubes.

The results of these experiments have shown that the deformation temperature and bending angle have significant effects on the average grain size and the reduction rate of the average grain size. With ongoing innovations and research, the metal tube industry is poised to provide even safer and more durable medical implants in the future.