A research team led by Professor Yoji Miyajima from the Division of Mechanical Engineering, Kanazawa University, and Professor Pinaki Prasad Bhattacharjee from the Indian Institute of Technology Hyderabad (IIT Hyderabad) proposed a recyclable alloy design method that actively utilizes metallic components contained in electronic material waste (e-waste), and successfully developed a new phase-separated high-entropy alloy (PS-HEA) as a demonstration of this approach.

High-entropy alloy (HEA)^(*1) are next-generation materials that achieve high strength and durability by mixing multiple metals in nearly equal proportions. However, conventional HEAs often contain expensive elements, posing cost-related challenges for practical applications. In this study, the researchers designed a new alloy by utilizing copper (Cu) found in scrap generated during the recycling of electronic devices. The developed alloy consists of two face-centered cubic (FCC) phases rich in Cu (FCC1 and FCC2), and was shown to simultaneously achieve an ultrafine microstructure of less than 1 μm and a high yield strength of approximately 850 MPa through mechanical processing and heat treatment.

This research presents a new direction for designing low-cost, high-performance structural materials that contribute to a sustainable, resource-circulating society. It is expected to make a significant impact on environmentally conscious manufacturing in the future.

The results of this study were published online in the  Journal of Alloys and Compounds on October 1, 2025, and officially appeared in the journal on October 15, 2025.

^{Figure: (a) Co-Cr-Fe-Mn-Ni alloy (conventional material), (b) (Co-Cr-Fe-Mn -Ni)-Cu alloys (this study).}

【Glossary】

*1:High-entropy alloys (HEA)
A new concept alloy in which several constituent elements are mixed together in approximately the same proportion (5 to 35%). By using as major elements that have been added only in trace amounts in conventional alloys, HEA alloys exhibit unique properties not found in existing materials, such as high strength and toughness, excellent heat resistance and corrosion resistance.

Press Release 【Japanese Only】

Journal：Journal of Alloys and Compounds

Researcher’s Information：Yoji Miyajima