Nanocrystalline CoCrFeNiCuAl high-entropy solid solution synthesized by mechanical alloying

Characterization of nanocrystalline CoCrFeNiTiAl high-entropy solid solution processed by mechanical alloying

“…The powder shows thermal stability up to 500 • C. Phase transformation begins at 520 • C. So we can see diffraction peaks corresponding to two BCC solid solutions obviously in the 600 • C annealed alloy. An FCC phase precipitates as a minor phase when the alloy was annealed at 700 • C for 1 h. The 700 • C annealed alloy powder shows identical crystal structure as the as-cast CoCrFeNiTiAl high-entropy alloy prepared by arc melt casting [15]. The alloy is also composed of simple solid solution phases after been annealed at 800 • C, but the diffraction peak intensity increases significantly.…”

“…However, the arc melt casting method can only prepare samples with limited shapes and sizes, which will definitely limit its industrial applications in the future. Mechanical alloying (MA) is a widely used solid state processing route for synthesis of advanced materials, which can easily lead to the formation of nanocrystalline and will definitely increase the properties and application scope of high-entropy alloys [13][14][15][16]. The CoCrFeNiTiAl x high-entropy alloy system had been investigated in our previous work and the results showed that the equiatomic CoCrFeNiTiAl alloy possessed excellent integrated mechanical properties [17].…”

Amorphization of equimolar alloys with HCP elements during mechanical alloying

“…Among these researches, it has been noted that HEAs prepared by melting method tend to form simple BCC and/or FCC solid solution phases due to high entropy effect and might possess a range of promising properties. However, for the HEA systems prepared by MA, such as Al-Fe-Ti-Cr-Zn-Cu [ Cu-Ni-Al-Co-Cr-Fe-Ti-Mo [27,28], Co-Cr-Fe-Ni-Cu-Al [29], and Cu-Ni-Co-Zn-Al-Ti [30], the tendency is different. Although they contain a variety of BCC, FCC, and HCP elements and first form simple BCC and/or FCC crystalline solid solution phases due to high entropy effect, prolonged milling causes these solid solution phases to transform into amorphous phase similar to the feature of type I amorphization.…”

“…Recently, various topics on HEAs have been reported, including microstructure and mechanical properties [12][13][14], effects of adding more elements [15,16], thermal stability [17][18][19], wear and corrosion resistance [20,21], hard coating [22,23], barrier films [24,25] and mechanical alloying behavior [26][27][28][29][30]. These are helpful in understanding HEAs in both academic and application aspects.…”

Explore the possibility of forming fcc high entropy alloys in equal-atomic systems CoFeMnNiM and CoFeMnNiSmM

“…Until now, most studies focus on the limited systems which consist of five to seven common metallic elements, such as Al, Bi, Co, Cr, Cu, Fe, Ni and Ti [4][5][6][7] . Yao et al [8] prepared the Bi-Fe-Co-NiMn HEA by an electrochemical method and measured its magnetic properties.…”