**4. Conclusion**

A new ECAP processing method called rotary-die equal channel angular pressing (RD-ECAP) was developed at Japan's National Institute of Advanced Industrial Science and Technology (AIST, formerly the National Industrial Research Institute of Nagoya (NIRIN)), to form fine-grained bulk materials such as aluminum alloys, aluminum composites, magnesium alloy, and titanium. RD-ECAP has the following features:


Researches on aluminium processing by ECAP deformation of more than 20 passes are still very few in the world. Therefore, other excellent effects or features are expected to be discovered in the future.
