Recently, high-entropy alloys (HEAs

Recently, high-entropy alloys (HEAs) have attracted increasing attentions because of their unique
compositions, microstructures, and adjustable properties [1–31]. They are loosely defined as solid
solution alloys that contain more than five principal elements in equal or near equal atomic percent
(at.%) [32]. Normally, the atomic fraction of each component is greater than 5 at.%. The multi-component
equi-molar alloys should be located at the center of a multi-component phase diagram, and their
configuration entropy of mixing reaches its maximum (RLnN; R is the gas constant and N the number
of component in the system) for a solution phase. These alloys are defined as HEAs by Yeh et al. [2],
and named by Cantor et al. [1,33] as multi-component alloys. Both refer to the same concept. There are
also some other names, such as multi-principal-elements alloys, equi-molar alloys, equi-atomic ratio
alloys, substitutional alloys, and multi-component alloys.
Cantor et al. [1,33] pointed out that a conventional alloy development strategy leads to an enormous
amount of knowledge about alloys based on one or two components, but little or no knowledge
about alloys containing several main components in near-equal proportions. Theoretical and experimental
works on the occurrence, structure, and properties of crystalline phases have been restricted
to alloys based on one or two main components. Thus, the information and understanding are highly
developed on alloys close to the corners and edges of a multi-component phase diagram, with much
less knowledge about alloys located at the center of the phase diagram, as shown schematically for
ternary and quaternary alloy systems in Fig. 1.1. This imbalance is significant for ternary alloys but
becomes rapidly much more pronounced as the number of components increases. For most quaternary
and other higher-order systems, information about alloys at the center of the phase diagram is
virtually nonexistent except those HEA systems that have been reported very recently.
In the 1990s, researchers began to explore for metallic alloys with super-high glass-forming ability
(GFA). Greer [29] proposed a confusion principle, which states that the more elements involved, the
lower the chance that the alloy can select viable crystal structures, and thus the greater the chance
of glass formation. Ma et al. [3] found that the best glass former is not exactly at the eutectic composition,
and has a shift towards the high-entropy zone in the phase diagram. Recently, Takeuchi et al.
[34] reported a high-entropy bulk metallic glass (BMG), which can have a critical size over 10 mm.
Zhao et al. [35] and Gao et al. [36] reported a high-entropy BMG, which can be plastically deformed
at room temperature. However, for some HEAs, their GFA is rather low, and they can only form

ผลลัพธ์ (เซโซโท) 1:

Haufinyane tjena, phahameng tlhokeho ea melao lits'epe tse kopantsoeng (HEAs) ba khahloa eketseha fuoa tlhokomelo ka lebaka la ho ikhethang
o hlophisitsoeng, microstructures, 'me fetolehang dithoto [1-31]. Ba loosely hlalosoa e le tiileng
tharollo lits'epe tse kopantsoeng tse nang le tse fetang tse hlano ka sehloohong element e lekanang kapa haufi le lekana athomo liphesente tse
(ka.%) [la 32]. Ka tloaelo, le athomo karoloana ea mong le e mong motsoako o moholo ho 5 kwa.%. The selotlolo motsoako
equi-molare lits'epe tse kopantsoeng lokela ho fumaneha ba le khubung ea dikhampani tsa motsoako mohato Setšoantšo se Qanollang, 'me bona
phetolo tlhokeho ea melao a hore ba tsoaka fihla eona boholo (RLnN; R ke khase kamehla le N palo
ea motsoako a tsamaiso) bakeng sa le tharollo motheo. Tsena lits'epe tse kopantsoeng ba hlalosoa e le HEAs ka Yeh et al a. [2] mo,
le e mong ea bitsoang ka Cantor et al a. [1,33] e le selotlolo motsoako lits'epe tse kopantsoeng. Ka bobeli a bua ka e tšoanang kgopolo. Ho na le
boetse ba bang ba mabitso a mang a, tse kang selotlolo ka sehloohong-element lits'epe tse kopantsoeng, equi-molare lits'epe tse kopantsoeng, equi-athomo kabo
lits'epe tse kopantsoeng, substitutional lits'epe tse kopantsoeng, 'me selotlolo motsoako lits'epe tse kopantsoeng.
Cantor et al a. [1,33] ile a bontša hore le tloaelehileng motsoako ya ntshetsopele ya isang e ngata haholo
palo ya tsebo ka lits'epe tse kopantsoeng e thehiloeng ngoe kapa tse peli dikarolo, empa hakaalo kapa ho hang tsebo
ka lits'epe tse kopantsoeng tse nang le tse 'maloa dikarolo tseno a kgauswi le-lekana boholo. Mogopolong le liteko
mesebetsi ka lebelloang, sebopeho, 'me makgetha a ho bonaletsang mekhahlelo e ba' nile ba thibeloa
ho lits'epe tse kopantsoeng e thehiloeng ngoe kapa tse peli dikarolo tseno. Kahoo, tlhahisoleseding le kutloisiso ba haholo
ntshetswa pele ka lits'epe tse kopantsoeng haufi le likhutlong le li metse ka thōko ea dikhampani tsa motsoako mohato Setšoantšo se Qanollang, nang le ho hongata
ka tlaase tsebo ka lits'epe tse kopantsoeng fumaneha ba le khubung ea pakeng e Setšoantšo se Qanollang, joalokaha ho bontšoa go dira ditshwantsho bakeng sa
ternary le quaternary motsoako tsamaiso a Feie. 1.1. Sena se imbalance ke ea bohlokoa bakeng sa ternary lits'epe tse kopantsoeng empa
e ba ka potlako lintho tse ngata bidiwa jaaka palo ea dikarolo eketseha. Bakeng sa ho fetisisa quaternary
le tse ling bokgoni bo hodimo ba tsamaiso, tlhahisoleseding e mabapi le lits'epe tse kopantsoeng ba le khubung ea pakeng e Setšoantšo se Qanollang ke
hoo e batlang e sa pheleng ntle ba HEA ditsamaiso tse ba 'nile ba e ile ea tlaleha haholo sa tsoa.
​​Ka bo-1990, bafuputsi ba o ile a qala ho hlahloba bakeng sa metallic lits'epe tse kopantsoeng le super phahameng khalase -forming matla a
(GFA). Greer [la 29] lohothwang le pherekano molao-motheo, e reng hore feta element amehang, le
tlaase monyetla wa hore le motsoako ka khetha ee solofetsang kristale mehaho e, 'me kahoo e khōlō le monyetla oa
ka khalase le thehoa. Ma et al a. [3] ile a fumana hore molemo ka ho fetisisa khalase pele e neng e ha hantle a le eutectic sebopeho,
le o na le battlefield ho ya ho motho phahameng tlhokeho ea melao libaka a pakeng e ya daekeramo. Haufinyane tjena, Takeuchi et al a.
[la 34] e ile ea tlaleha e mong ea phahameng tlhokeho ea melao bongata metallic khalase (BMG), e ka ba le mahlonoko tseo ho leng boholo fetang 10 limilimithara.
Zhao et al a. [35] le Gao et al a. [La 36] e ile ea tlaleha e mong ea phahameng tlhokeho ea melao BMG, tse ka globally deformed
leng motjhesong wa kamore. Leha ho le joalo, etsoe ba bang HEAs, bona GFA ke ho e-na tlase, 'me ba ka feela theha