CoCrFeNi inonyatso dzidza face-centered cubic (fcc) high-entropy alloy (HEA) ine yakanakisa ductility asi ine simba shoma.Chinangwa chechidzidzo ichi ndechekuvandudza kuenzana kwesimba uye ductility yemaHEA akadaro nekuwedzera huwandu hwakasiyana hweSiC uchishandisa nzira yekunyungudika kwearc.Izvo zvakasimbiswa kuti kuvapo kwechromium munheyo HEA kunokonzera kuora kweSiC panguva yekunyunguduka.Nekudaro, kudyidzana kwemahara kabhoni nechromium kunotungamira kune in situ kuumbwa kwechromium carbides, nepo silicon yakasununguka inoramba iri mumhinduro munheyo HEA uye / kana kupindirana nezvinhu zvinoumba base HEA kugadzira silicides.Sezvo zvinyorwa zveSiC zvinowedzera, chikamu che microstructure chinoshanduka mune zvinotevera: fcc → fcc + eutectic → fcc + chromium carbide flakes → fcc + chromium carbide flakes + silicide → fcc + chromium carbide flakes + silicide + graphite balls / graphite flakes.Macomposites anozobuda anoratidza huwandu hwakasiyana-siyana hwema mechanical properties (goho resimba rinobva pa277 MPa pa60% kureba kusvika 2522 MPa pa6% elongation) zvichienzaniswa neakajairika alloys uye high entropy alloys.Mamwe epamusoro entropy composites akagadzirwa anoratidza yakanakisa musanganiswa wezvivakwa zvemuchina (goho simba 1200 MPa, kureba 37%) uye kutora matunhu aisambosvikika pagoho rekurebesa-kurebesa dhiyagiramu.Pamusoro pekurebesa kunoshamisa, kuoma uye kusimba kwegoho reHEA macomposites ari muchikamu chakafanana nemagirazi esimbi mazhinji.Naizvozvo, zvinotendwa kuti kuvandudzwa kweakakwira-entropy macomposites anogona kubatsira kuwana yakanakisa musanganiswa wemakanika zvivakwa zvepamberi zvimiro zvekushandisa.
Iko kuvandudzwa kwepamusoro entropy alloys ipfungwa nyowani inovimbisa mumetallurgy1,2.Yakakwira entropy alloys (HEA) yakaratidza mune akati wandei zviitiko kusanganisa kwakanakisa kwemuviri uye mekiniki zvivakwa, kusanganisira yakakwira kupisa kugadzikana3,4 superplastic elongation5,6 kuneta kuramba7,8 corrosion resistance9,10,11, kupfeka kwakanakisa kuramba12,13,14 ,15 and tribological properties15 ,16,17 even at high temperatures18,19,20,21,22 and mechanical properties at low temperatures23,24,25.Iko kusanganisa kwakanakisa kwemechini zvivakwa muHEA kunowanzo kuverengerwa kune mana makuru mhedzisiro, anoti yakakwirira configurational entropy26, yakasimba lattice distortion27, inononoka diffusion28 uye cocktail effect29.HEAs inowanzoiswa seFCC, BCC uye HCP marudzi.FCC HEA inowanzo ine zvinhu zvekuchinja zvakaita seCo, Cr, Fe, Ni uye Mn uye inoratidza yakanakisa ductility (kunyangwe pazasi tembiricha25) asi yakaderera simba.BCC HEA inowanzo umbwa nepamusoro density zvinhu zvakaita seW, Mo, Nb, Ta, Ti uye V uye ine simba rakawandisa asi yakaderera ductility uye yakaderera chaiyo simba30.
Iyo microstructural gadziriso yeHEA yakavakirwa pamachining, thermomechanical processing uye kuwedzerwa kwezvinhu kwakaongororwa kuti uwane yakanakisa musanganiswa wemakanika zvivakwa.CoCrFeMnNi FCC HEA inoiswa pasi pepurasitiki yakakomba deformation ne-high-pressure torsion, izvo zvinotungamira kuwedzera kwakanyanya kwekuoma (520 HV) uye simba (1950 MPa), asi kuvandudzwa kwenanocrystalline microstructure (~ 50 nm) inoita kuti alloy brittle31 .Zvakaonekwa kuti kubatanidzwa kwe twinning ductility (TWIP) uye shanduko yakakonzera purasitiki (TRIP) muCoCrFeMnNi HEAs inopa basa rakanaka kuomarara zvichikonzera kusimba kwepamusoro ductility, zvisinei nekurasikirwa kweiyo chaiyo tensile simba kukosha.Pazasi (1124 MPa) 32. Kuumbwa kweiyo layered microstructure (inosanganisira yakaonda yakaremara layer uye isina kuchinjika core) muCoCrFeMnNi HEA uchishandisa pfuti peening yakaguma nekuwedzera kwesimba, asi kuvandudzwa uku kwakangogumira kusvika 700 MPa33.Mukutsvaga zvinhu zvine mubatanidzwa wakanakisa wesimba uye ductility, kuvandudzwa kwemultiphase HEAs uye eutectic HEAs vachishandisa mawedzero easiri isoatomic zvinhu zvakare yakaongororwa34,35,36,37,38,39,40,41.Zvechokwadi, zvakaonekwa kuti kugovera kwakanyatsonaka kwezvikamu zvakaoma uye zvinyoro mu eutectic high-entropy alloys zvinogona kutungamirira kuhutano huri nani hwesimba uye ductility35,38,42,43.
Iyo CoCrFeNi sisitimu inodzidzwa zvakanyanya single-phase FCC yakakwira-entropy alloy.Iyi sisitimu inoratidza kukurumidza kushanda kuomarara zvivakwa44 uye yakanakisa ductility45,46 pane zvese zvakaderera uye zvakanyanya tembiricha.Kuedza kwakasiyana-siyana kwakaitwa kuvandudza simba rayo rakaderera (~ 300 MPa) 47,48 kusanganisira kugadzirisa zviyo25, heterogeneous microstructure49, precipitation50,51,52 uye shanduko-induced plasticity (TRIP)53.Kunatswa kwezviyo zvekukandwa kumeso-centered cubic HEA CoCrFeNi nekudhirowa kunotonhora pasi pemamiriro akaomarara kunowedzera simba kubva pa300 MPa47.48 kusvika 1.2 GPa25, asi kunoderedza kurasikirwa kweductility kubva kupfuura 60% kusvika 12.6%.Kuwedzerwa kweAl kune HEA yeCoCrFeNi kwakakonzera kuumbwa kweiyo heterogeneous microstructure, iyo yakawedzera simba regoho kusvika ku786 MPa uye kureba kwayo kusvika ku22% 49.CoCrFeNi HEA yakawedzerwa neTi neAl kuti igadzire mvura, nokudaro ichigadzira kusimba kwemvura, ichiwedzera goho rayo kusvika ku645 MPa uye kurebesa kusvika 39% 51.Iyo TRIP michina (face-centered cubic → hexahedral martensitic shanduko) uye twinning yakawedzera simba rekusimba reCoCrFeNi HEA kusvika 841 MPa uye kureba panguva yekuzorora kusvika 76% 53.
Kuedza kwakaitwawo kuwedzera ceramic kusimbisa kune HEA face centered cubic matrix kugadzira yakakwira entropy composites inogona kuratidza zvirinani musanganiswa wesimba uye ductility.Macomposites ane yakakwira entropy akagadziriswa ne vacuum arc melting44, mechanical alloying45,46,47,48,52,53, spark plasma sintering46,51,52, vacuum inopisa pressing45, inopisa isostatic pressing47,48 uye kuvandudzwa kwekuwedzera kwekugadzira maitiro43. 50.Carbides, oxides uye nitrides seWC44, 45, 46, Al2O347, SiC48, TiC43, 49, TiN50 uye Y2O351 yakashandiswa seceramic reinforcement mukugadzirwa kweHEA composites.Kusarudza iyo chaiyo HEA matrix uye ceramic inonyanya kukosha pakugadzira uye kugadzira yakasimba uye yakasimba HEA inoumbwa.Mubasa iri, CoCrFeNi yakasarudzwa sematrix zvinhu.Huwandu hwakasiyana-siyana hweSiC hwakawedzerwa kuCoCrFeNi HEA uye mhedzisiro yavo pane iyo microstructure, chikamu kuumbwa, uye michina zvivakwa zvakadzidzwa.
Yakakwirira-kuchena simbi Co, Cr, Fe, uye Ni (99.95 wt %) uye SiC hupfu (kuchena 99%, saizi -400 mesh) muchimiro chezvikamu zvekutanga zvakashandiswa seyakagadzirwa kugadzirwa kweHEA composites.Iyo isoatomic kuumbwa kweCoCrFeNi HEA yakatanga kuiswa muhemispherical mvura-yakanyoroveswa mhangura yemhangura, uye ipapo kamuri yacho yakabudiswa kune 3 · 10-5 mbar.Yakakwira kuchena argon gasi inounzwa kuti iwane vacuum inodiwa kuti arc inyunguduke ine isingabatike tungsten electrodes.Iyo inoguma ingots inopindurwa uye inogadziriswa kashanu kuti ive nechokwadi chehomogeneity yakanaka.Yakakwirira-entropy macomposites emhando dzakasiyana-siyana dzakagadzirirwa nekuwedzera imwe chiyero cheSiC kune yakaguma equiatomic CoCrFeNi mabhatani, ayo akaiswazve homogenized nekashanu-kaviri inversion uye remelting mune yega yega.Bhatani rakaumbwa kubva kune yakakonzerwa rakagadzirwa rakachekwa uchishandisa EDM kuti uwedzere kuongororwa uye maitiro.Samples ezvidzidzo zvemicrostructural akagadzirirwa zvinoenderana neyakajairwa metallographic nzira.Kutanga, sampuli dzakaongororwa pachishandiswa microscope yakareruka (Leica Microscope DM6M) ine software Leica Image Analysis (LAS Phase Nyanzvi) yehuwandu hwechikamu chekuongorora.Mifananidzo mitatu yakatorwa munzvimbo dzakasiyana nenzvimbo yakazara ye27,000 µm2 yakasarudzwa kuti iongororwe chikamu.Zvimwe zvakadzama zvidzidzo zvemicrostructural, zvinosanganisira ongororo yekuumbwa kwemakemikari uye ongororo yekugovera zvinhu, zvakaitwa pa scanning electron microscope (JEOL JSM-6490LA) ine simba dispersive spectroscopy (EDS) yekuongorora system.Chimiro chekristani chimiro cheHEA chinosanganiswa chakaitwa uchishandisa X-ray diffraction system (Bruker D2 phase shifter) uchishandisa CuKα sosi ine nhanho saizi ye0.04 °.Mhedzisiro yekuchinja kweiyo microstructural pamichina yeHEA macomposites yakadzidzwa uchishandisa Vickers microhardness bvunzo uye compression bvunzo.Pakuomarara bvunzo, mutoro we500 N unoiswa kwegumi neshanu uchishandisa angangoita gumi indentations pamuenzaniso.Kudzvanya bvunzo dzeHEA composites pakupisa kwekamuri kwakaitwa pazvienzaniso zvine rectangular (7 mm × 3 mm × 3 mm) paShimadzu 50KN universal test machine (UTM) panguva yekutanga strain rate ye0.001/s.
Yakakwira entropy composite, yakazonzi sampuli S-1 kusvika S-6, yakagadzirirwa nekuwedzera 3%, 6%, 9%, 12%, 15%, uye 17% SiC (zvese nehuremu%) kune CoCrFeNi matrix. .zvichiteerana.Sample yereferensi iyo isina SiC yakawedzerwa inozonzi semuenzaniso S-0.Optical micrographs yeakagadziridzwa HEA macomposites anoratidzwa muFig.1, apo, nekuda kwekuwedzerwa kwezviwedzerwa zvakasiyana-siyana, imwe-phase microstructure yeCoCrFeNi HEA yakashandurwa kuva microstructure ine zvikamu zvakawanda zvine morphology yakasiyana, hukuru, uye kugovera.Huwandu hweSiC mukuumbwa.Huwandu hwechikamu chega chega hwakatemwa kubva pakuongorora kwemifananidzo uchishandisa LAS Phase Nyanzvi software.Iyo inset kuMufananidzo 1 (kumusoro kurudyi) inoratidza muenzaniso wenzvimbo yekuongorora uku, pamwe nechikamu chenzvimbo chechikamu chimwe nechimwe.
Optical micrographs ezvakagadzirwa zvakakwirira-entropy composites: (a) C-1, (b) C-2, (c) C-3, (d) C-4, (e) C-5 uye (f) C- 6.Iyo inset inoratidza muenzaniso wekusiyanisa-yakavakirwa mufananidzo chikamu chekuongorora mhinduro uchishandisa iyo LAS Phase Nyanzvi software.
Sezvinoratidzwa mufig.1a, eutectic microstructure yakaumbwa pakati pematrix volumes yeC-1 composite, apo huwandu hwematrix uye eutectic phases inofungidzirwa se 87.9 ± 0.47% uye 12.1% ± 0.51%, maererano.Muchikamu (C-2) chinoratidzwa mumufananidzo 1b, hapana zviratidzo zveeutectic reaction panguva yekusimbisa, uye microstructure yakasiyana zvachose kubva kune yeC-1 composite inoonekwa.Iyo microstructure yeC-2 composite yakanaka uye ine mahwendefa matete (carbides) akagoverwa zvakafanana muchikamu che matrix (fcc).Izvo zvikamu zvevhoriyamu zvematrix uye carbide zvinofungidzirwa pa72 ± 1.69% uye 28 ± 1.69%, zvichiteerana.Mukuwedzera kune matrix uye carbide, chikamu chitsva (silicide) chakawanikwa muC-3 composite, sezvakaratidzwa muFig. 1c, apo zvikamu zvevhoriyamu zvesilicide yakadaro, carbide, uye matrix phases inofungidzirwa inenge 26.5% ± 0.41%, 25.9 ± 0.53, uye 47.6 ± 0.34, zvichiteerana.Chimwe chikamu chitsva (graphite) chakaonekwawo mune microstructure yeC-4 composite;zvikamu zvina zvakaonekwa.Chikamu chegraphite chine chimiro chakasiyana cheglobular chine rima rakasiyana mumifananidzo yemaziso uye inongowanikwa muzvikamu zvidiki (inofungidzirwa kuti chikamu chevhoriyamu chinongosvika 0.6 ± 0.30%).Mumakompositi C-5 uye C-6, zvikamu zvitatu chete zvakaonekwa, uye rima rinosiyanisa graphite chikamu mune aya macomposites rinoonekwa muchimiro cheflakes.Kuenzaniswa nema graphite flakes muComposite S-5, ma graphite flakes muComposite S-6 akafara, mapfupi, uye anowanzoitika.Kuwedzera kunowirirana kwezvinyorwa zve graphite kwakaonekwawo kubva ku14.9 ± 0.85% muC-5 composite kusvika kune 17.4 ± 0.55% muC-6 composite.
Kuenderera mberi nekuongorora yakadzama microstructure uye makemikari kuumbwa kwechikamu chimwe nechimwe muHEA composite, samples dzakaongororwa uchishandisa SEM, uye EMF point analysis uye kemikari mepu yakaitwa zvakare.Mhedzisiro yecomposite C-1 inoratidzwa mufig.2, uko kuvepo kwe eutectic musanganiswa unoparadzanisa matunhu eiyo main matrix chikamu kunoonekwa zvakajeka.Mepu yemakemikari ye-composite C-1 inoratidzwa muFig. 2c, iyo inogona kuonekwa kuti Co, Fe, Ni, uye Si zvakagoverwa zvakafanana muchikamu chematrix.Zvisinei, zvishoma zveCr zvakawanikwa muchikamu chematrix chichienzaniswa nezvimwe zvinhu zvehesi HEA, zvichiratidza kuti Cr yakapararira kunze kwematrix.Kuumbwa kweiyo chena eutectic chikamu muSEM mufananidzo wakapfuma muchromium uye kabhoni, zvichiratidza kuti iri chromium carbide.Kusavepo kweDiscrete SiC particles mu microstructure, yakasanganiswa neinocherechedzwa yakaderera yemukati yechromium mumatrix uye kuvapo kweeutectic misanganiswa ine chromium-rich phases, inoratidza kuparara kwakazara kweSiC panguva yekunyunguduka.Nekuda kwekuparara kweSiC, silicon inonyungudika muchikamu chematrix, uye kabhoni yemahara inopindirana nechromium kugadzira chromium carbides.Sezvinoonekwa, kabhoni chete ndiyo yakatemwa nenzira yeEMF, uye kuumbwa kwechikamu kwakasimbiswa nekuzivikanwa kwehunhu hwecarbide peaks muX-ray diffraction mapatani.
(a) SEM mufananidzo wemuenzaniso S-1, (b) mufananidzo wakakurisa, (c) mepu yezvinhu, (d) EMF mhedzisiro panzvimbo dzakaratidzwa.
Kuongororwa kwemubatanidzwa C-2 kunoratidzwa mufig.3. Zvakafanana nekuonekwa mu optical microscopy, SEM kuongorora kwakaratidza chimiro chakanaka chinoumbwa nezvikamu zviviri chete, nekuvapo kwechidimbu chelamellar chikamu chakagoverwa zvakaenzana mukati mechimiro.matrix chikamu, uye hapana eutectic chikamu.Iyo yekugovera element uye EMF poindi kuongororwa kweiyo lamellar chikamu yakaratidza yakakwira yemukati yeCr (yero) uye C (girinhi) muchikamu ichi, iyo inoratidza zvakare kuparara kweSiC panguva yekunyunguduka uye kupindirana kwekabhoni yakaburitswa ine chromium mhedzisiro. .Iyo VEA matrix inoumba lamellar carbide chikamu.Kugoverwa kwezvinhu uye kuongororwa kwepoindi kwechikamu chematrix kwakaratidza kuti mazhinji ecobalt, iron, nickel uye silicon aripo muchikamu chematrix.
(a) SEM mufananidzo wemuenzaniso S-2, (b) mufananidzo wakakurisa, (c) mepu yezvinhu, (d) EMF mhedzisiro panzvimbo dzakaratidzwa.
SEM zvidzidzo zveC-3 zvinosanganiswa zvakaratidza kuvepo kwezvikamu zvitsva mukuwedzera kune carbide uye matrix zvikamu.Mepu yekutanga (Fig. 4c) uye EMF point analysis (Fig. 4d) inoratidza kuti chikamu chitsva chakapfuma nickel, cobalt, uye silicon.
(a) SEM mufananidzo wemuenzaniso S-3, (b) mufananidzo wakakurisa, (c) mepu yezvinhu, (d) EMF mhedzisiro panzvimbo dzakaratidzwa.
Mhedzisiro yeSEM uye EMF kuongororwa kweC-4 composite inoratidzwa muFig.5. Mukuwedzera kune zvikamu zvitatu zvakaonekwa mumubatanidzwa C-3, kuvapo kwemagirafu nodules kwakawanikwa zvakare.Chikamu chevhoriyamu chesilicon-rich chikamu chakakwirawo kupfuura icho cheC-3 chinoumbwa.
(a) SEM mufananidzo wemuenzaniso S-4, (b) mufananidzo wakakurisa, (c) mepu yezvinhu, (d) EMF mhedzisiro panzvimbo dzakaratidzwa.
Mhedzisiro yeSEM uye EMF spectra yemakompositi S-5 uye S-6 inoratidzwa muMifananidzo 1 uye 2. 6 uye 7, zvichiteerana.Mukuwedzera kune nhamba shomanana yezvikamu, kuvapo kwe graphite flakes kwakaonekwawo.Zvose nhamba ye graphite flakes uye vhoriyamu chikamu chesilicon-ine chikamu muC-6 inoumbwa zvakakura kudarika muC-5 composite.
(a) SEM mufananidzo wemuenzaniso C-5, (b) maonero akawedzerwa, (c) mepu yekutanga, (d) EMF mhedzisiro panzvimbo dzakaratidzwa.
(a) SEM mufananidzo wemuenzaniso S-6, (b) mufananidzo wakakurisa, (c) element mepu, (d) EMF mhedzisiro panzvimbo dzakaratidzwa.
Crystal chimiro chechimiro cheHEA macomposites chakaitwa zvakare uchishandisa XRD zviyero.Chigumisiro chinoratidzwa muMufananidzo 8. Muchidimbu chekuparadzanisa kwenheyo WEA (S-0), chete mapeji anoenderana nefcc phase anooneka.X-ray diffraction mapatani emakompositi C-1, C-2, uye C-3 yakaratidza kuvepo kwemamwe machuru anoenderana nechromium carbide (Cr7C3), uye kusimba kwavo kwaive kwakadzikira kumasampuli C-3 neC-4, airatidza. izvo zvakare ne data EMF yemasampuli aya.Peaks inoenderana neCo / Ni silicides yakaonekwa kune sampuli S-3 uye S-4, zvakare inopindirana nemigumisiro yemepu yeEDS inoratidzwa muMifananidzo 2 uye 3. Sezvinoratidzwa mumufananidzo 3 uye Mufananidzo 4. 5 uye S-6 mapeji akaonekwa. zvinoenderana negraphite.
Zvese zviri zviviri microstructural uye crystallographic maitiro eakagadziridzwa macomposites anoratidza kuora kweiyo SiC yakawedzerwa.Izvi zvinokonzerwa nekuvapo kwechromium muVEA matrix.Chromium ine hukama hwakasimba kwazvo hwekabhoni 54.55 uye inopindirana nekabhoni yemahara kuita carbides, sezvinoratidzwa nekudzikira kwakacherechedzwa kwechromium yemukati mematrix.Si inopinda muchikamu chefcc nekuda kwekuparadzaniswa kweSiC56.Nokudaro, kuwedzera kwekuwedzera kweSiC kune chigadziko HEA kwakakonzera kuwedzera kwehuwandu hwechikamu checarbide uye chiyero cheSi chakasununguka mu microstructure.Zvakaonekwa kuti iyi yekuwedzera Si inoiswa mumatrix pazvikamu zvakaderera (muzvikamu S-1 uye S-2), nepo pamatunhu akakwirira (anosanganisa S-3 kusvika kuS-6) zvinoguma nekuwedzera cobalt deposition/.nickel silicide.Iyo yakajairwa enthalpy yekuumbwa kweCo uye Ni silicides, yakawanikwa neakananga synthesis yakakwirira-temperature calorimetry, ndeye -37.9 ± 2.0, -49.3 ± 1.3, -34.9 ± 1.1 kJ mol -1 yeCo2Si, CoSi uye CoSi2, zvichiteerana, nepo izvi kukosha nde - 50.6 ± 1.7 uye - 45.1 ± 1.4 kJ mol-157 yeNi2Si uye Ni5Si2, zvichiteerana.Aya maitiro akadzikira pane kupisa kwekuumbwa kweSiC, zvichiratidza kuti kupatsanurwa kweSiC kunotungamira mukuumbwa kweCo/Ni silicides kunofadza nesimba.Mune ese S-5 uye S-6 macomposites, yakawedzera yemahara silicon yaivepo, iyo yakanyudzwa kupfuura kuumbwa kwesilicide.Iyi silicon yemahara yakawanikwa ichibatsira kune iyo graphitization inoonekwa mune yakajairika steels58.
Iwo emakanika zvimiro zveakagadziridzwa ceramic-akasimbiswa macomposites akavakirwa paHEA anoongororwa nekumanikidza bvunzo uye kuomarara bvunzo.Kushungurudzika-kunetseka kwema curves ezvakagadzirwa zvakasanganiswa zvinoratidzwa muFig.9a, uye mumufananidzo 9b inoratidza scatterplot pakati pesimba regoho rakananga, simba rezvibereko, kuoma, uye kureba kwezvakagadzirwa zvakaumbwa.
(a) Compressive strain curves uye (b) scatterplots inoratidza kushushikana kwegoho chairo, simba regoho, kuoma uye kurebesa.Ziva kuti zvienzaniso chete S-0 kusvika S-4 zvinoratidzwa, sezvo zvienzaniso S-5 neS-6 zvine hurema hwakakura hwekukanda.
Sezvinoonekwa mufig.9, simba regoho rakawedzera kubva pa136 MPa yenheyo yeVES (C-0) kusvika ku2522 MPa yeC-4 composite.Zvichienzaniswa neiyo yekutanga WPP, iyo S-2 inoumbwa yakaratidza yakanakira kurebesa kutadza kweinenge 37%, uye zvakare yakaratidza yakakwira zvakanyanya goho simba makoshero (1200 MPa).Iyo yakanakisa kusanganiswa kwesimba uye ductility yeiyi composite inokonzerwa nekuvandudzika kweiyo microstructure yakazara, kusanganisira yunifomu yekugovera yakanaka carbide lamellae mukati meiyo microstructure, iyo inotarisirwa kuvharidzira kufamba kwekufamba.Simba regoho reC-3 neC-4 composites 1925 MPa uye 2522 MPa, zvichiteerana.Aya masimba egoho repamusoro anogona kutsanangurwa neiyo yakakwira vhoriyamu chikamu checemented carbide uye silicide phases.Nekudaro, kuvapo kwezvikamu izvi zvakare kwakakonzera kurebesa pakuputsika kwe7%.Kushushikana-kunetseka kwema curves e base composites CoCrFeNi HEA (S-0) uye S-1 ari convex, achiratidza activation of twinning effect kana TRIP59,60.Kuenzaniswa nesample S-1, iyo stress-strain curve yesample S-2 ine concave shape at strain inosvika 10.20%, zvinoreva kuti yakajairika dislocation slip ndiyo huru deformation mode yesample mune ino deformed state60,61 .Nekudaro, iyo yekuomeswa kweyero mumuenzaniso uyu inoramba yakakwira pane yakakura dhizaini, uye pamhando yepamusoro shanduko yekutenderera inooneka zvakare (kunyangwe zvisingagone kutorwa kuti izvi zvinokonzerwa nekutadza kwemafuta anomanikidza mitoro).)Macomposites C-3 neC-4 ane mapurasitiki mashoma nekuda kwekuvapo kwepamusoro vhoriyamu zvikamu zve carbides uye silicides mune microstructure.Kudzvinyirira bvunzo dzemasamples ecomposites C-5 uye C-6 hazvina kuitwa nekuda kwekuremara kwakakura kwekukanda pane aya masampuli ecomposites (ona Fig. 10).
Stereomicrographs yekukanda kukanganisa (inoratidzwa nemiseve yakatsvuka) mumasampuli emakompositi C-5 uye C-6.
Mhedzisiro yekuyera kuomarara kweVEA kompositi inoratidzwa muFig.9b.Iyo base WEA ine kuoma kwe130±5 HV, uye samples S-1, S-2, S-3 uye S-4 ine hurema hunokosha hwe250±10 HV, 275±10 HV, 570±20 HV uye 755±20 HV.Kuwedzera kwekuoma kwaiva mukubvumirana kwakanaka nekushandurwa kwesimba regoho rakawanikwa kubva kumanikidziro ekuedza uye yakabatanidzwa nekuwedzera kwehuwandu hwehuwandu hwehuwandu hwehuwandu.Iyo yakaverengerwa yakananga goho simba rinobva pane chinangwa chekuumbwa kwemuenzaniso wega wega unoratidzwawo mufig.9b.Muzhinji, iyo yakanakisa kusanganisa kwesimba regoho (1200 MPa), kuoma (275 ± 10 HV), uye kurebesa kurebesa kukundikana (~ 37%) inocherechedzwa kune inoumbwa C-2.
Kuenzanisa kwesimba regoho uye kurebesa kwechikafu chakagadzirwa nezvinhu zvemakirasi akasiyana zvinoratidzwa muFig. 11a.Macomposites akavakirwa paCoCrFeNi muchidzidzo ichi airatidza kureba kwepamusoro pane chero kupihwa stress level62.Zvinogona kuonekwa zvakare kuti zvimiro zveHEA zvinoumba maumbirwo akagadzirwa muchidzidzo ichi zviri munzvimbo yaimbove isina kugarwa yechikamu chesimba regoho maringe nekurebesa.Pamusoro pezvo, macomposites akagadzirwa ane huwandu hwakawanda hwekusanganisa simba (277 MPa, 1200 MPa, 1925 MPa uye 2522 MPa) uye elongation (> 60%, 37%, 7.3% uye 6.19%).Kusimba kwegoho chinhu chakakoshawo pakusarudzwa kwezvinhu zveinjiniya zvepamberi63,64.Panyaya iyi, HEA macomposites echigadzirwa chazvino anoratidza musanganiswa wakanakisa wesimba regoho uye kurebesa.Izvi zvinodaro nekuti kuwedzerwa kweiyo low density SiC kunokonzeresa macomposites ane yakakwira chaiyo goho simba.Iyo chaiyo yegoho simba uye elongation yeHEA composites iri mumutsara wakafanana neHEA FCC uye refractory HEA, sezvakaratidzwa muFig. 11b.Kuoma uye kusimba kwegoho kwezvakagadzirwa zvinoumba zviri mumutsara wakafanana nemagirazi makuru esimbi65 (Fig. 11c).Magirazi esimbi makuru (BMS) anoratidzirwa nekuomarara kwakanyanya uye kusimba kwegoho, asi kureba kwawo kunogumira66,67.Nekudaro, kuoma uye kusimba kwegoho kwemamwe eHEA macompositi akagadzirwa muchidzidzo ichi zvakaratidzawo kurebesa kukuru.Nekudaro, zvakagumisirwa kuti macomposites akagadzirwa neVEA ane yakasarudzika uye yakatsvakwa-musanganiswa wemakanika zvivakwa zvezvakasiyana zvimiro zvekushandisa.Iyi yakasarudzika musanganiswa wemakanika zvivakwa inogona kutsanangurwa nekuparadzirwa kweyunifomu kweakaoma carbides akaumbwa mu situ mune FCC HEA matrix.Zvisinei, sechikamu chechinangwa chekuwana kusanganiswa kwesimba riri nani, kuchinja kwe microstructural kunokonzerwa nekuwedzera kwezvikamu zveceramic kunofanira kunyatsodzidza uye kudzorwa kudzivirira kukanganisa kukanda, zvakadai seanowanikwa muS-5 uye S-6 composites, uye ductility.murume kana mukadzi.
Zvigumisiro zvechidzidzo ichi zvakaenzaniswa nezvinhu zvakasiyana-siyana zvekugadzirisa uye HEAs: (a) kureba kunopesana negoho simba62, (b) kushushikana kwegoho kunopesana ne ductility63 uye (c) kubereka simba rinopesana nekuoma65.
Iyo microstructure uye mechanical properties yenhevedzano yeHEA-ceramic composites yakavakirwa paHEA CoCrFeNi system pamwe nekuwedzera kweSiC yakadzidzwa uye mhedziso dzinotevera dzakatorwa:
Yakakwira entropy alloy composites inogona kubudirira kuvandudzwa nekuwedzera SiC kuCoCrFeNi HEA uchishandisa arc kunyungudika nzira.
SiC inoora panguva yekunyunguduka kwearc, zvichiita kuti pave nekugadzirwa mu situ ye carbide, silicide uye graphite phases, kuvapo uye vhoriyamu chikamu cheiyo zvinoenderana nehuwandu hweSiC yakawedzerwa kune base HEA.
HEA macomposites anoratidza akawanda akanakisa emuchina zvivakwa, ane zvivakwa zvinowira munzvimbo dzaimbova dzisina kugarwa pane goho resimba rinopesana nechikamu chekureba.Simba regoho reHEA rinoumbwa rakagadzirwa uchishandisa 6 wt% SiC yaive yakapetwa kasere iyo yebase HEA ichichengetedza 37% ductility.
Iko kuoma uye kusimba kwegoho kweHEA macomposites ari muhuwandu hwemagirazi esimbi akawanda (BMG).
Zvakawanikwa zvinoratidza kuti macomposites epamusoro-entropy alloy anomiririra nzira inovimbisa yekuwana musanganiswa wakanakisa wesimbi-mechanicha zvivakwa zvepamberi zvimiro zvekushandisa.
Nguva yekutumira: Jul-12-2023