**8.3 Powder metallurgy**

Another important method is powder metallurgy, i.e., mechanical mixing of constituent powders followed by densification by heat treatment such as hot-pressing, cold isostatic pressing, or SPS treatment (**Figure 9**). The powder metallurgy method is beneficial in improving the homogeneity and distribution of powders.

**233**

**Author details**

Ashutosh Sharma1,2

Republic of Korea

Republic of Korea

*High-Entropy Alloys for Micro- and Nanojoining Applications*

Heat treatment is used to prepare the bulk specimen which also relieves the stress in

Varalakshmi and her co-workers produced nanocrystalline CuNiCoZnAlTi HEA with a BCC structure by powder metallurgy and showed a remarkable increment in the hardness and compressive strength of 8.79 GPa and 2.76 GPa, respectively, higher than the current hard-facing alloys [47]. Other researchers have also produced HEAs with sputtering, laser cladding, and electrodeposition in a few studies. However, until now, a wide exploration of these HEAs for microjoining is very limited.

This HEA filler research has the ability to develop a new microjoining material which can join dissimilar materials (ceramic-metal, ceramic-superalloy, ceramicsteel, etc.) and will contribute to the integration of various metallic and ceramic components toward achieving high joint strength, protecting devices, and saving energy. This invention will largely improve the performance of the conventional IMC containing brazing fillers. The development of IMC free fillers for joining is the long-standing demand for microjoining industries. This high quality and the innovative project can be further expanded and commercialized to Korean companies looking for cheap and IMC-free Al alloys for joining for mass production. The combination of HEA filler with those of industry will provide the scale and credibility needed to bring high-entropy alloy technology fully into the market. Newly developed alloys will be patented and commercialized to global companies to realize

*DOI: http://dx.doi.org/10.5772/intechopen.91166*

**9. Summary and guidelines**

a capital sum and raise the world economy.

1 Department of Energy Systems Research, Ajou University, Suwon,

\*Address all correspondence to: stannum.ashu@gmail.com

provided the original work is properly cited.

2 Department of Materials Science and Engineering, Ajou University, Suwon,

© 2020 The Author(s). Licensee IntechOpen. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/ by/3.0), which permits unrestricted use, distribution, and reproduction in any medium,

the powders to get the stable HEAs (**Figure 9**).

**Figure 9.** *Mechanical alloying and sintering diagram.*

Heat treatment is used to prepare the bulk specimen which also relieves the stress in the powders to get the stable HEAs (**Figure 9**).

Varalakshmi and her co-workers produced nanocrystalline CuNiCoZnAlTi HEA with a BCC structure by powder metallurgy and showed a remarkable increment in the hardness and compressive strength of 8.79 GPa and 2.76 GPa, respectively, higher than the current hard-facing alloys [47]. Other researchers have also produced HEAs with sputtering, laser cladding, and electrodeposition in a few studies. However, until now, a wide exploration of these HEAs for microjoining is very limited.
