CoCrFeNi bụ cubic (fcc) ihu gbadoro anya nke ọma (HEA) nwere ezigbo ductility mana oke ike. Ihe a na-elekwasị anya n'ọmụmụ ihe a bụ ịkwalite nguzozi nke ike na ductility nke HEA dị otú ahụ site n'ịgbakwunye SiC dị iche iche site na iji usoro mgbaze arc. Ekwuputala na ọnụnọ nke chromium na isi HEA na-akpata mwepu nke SiC n'oge agbaze. Ya mere, mmekọrịta nke carbon efu na chromium na-eduga na nguzobe nke chromium carbides, ebe silicon free na-anọgide na ngwọta na isi HEA na / ma ọ bụ na-emekọ ihe na ihe ndị mejupụtara HEA isi iji mepụta silicides. Ka ọdịnaya SiC na-abawanye, usoro microstructure na-agbanwe n'usoro ndị a: fcc → fcc + eutectic → fcc + chromium carbide flakes → fcc + chromium carbide flakes + silicide → fcc + chromium carbide flakes + silicide + graphite bọọlụ / flakes graphite. Ngwakọta ndị a na-esi na ya pụta na-egosiputa ọtụtụ ihe eji arụ ọrụ (ike na-esi na 277 MPa na ihe karịrị 60% elongation na 2522 MPa na 6% elongation) ma e jiri ya tụnyere alloys omenala na elu entropy alloys. Ụfọdụ n'ime ihe ndị mejupụtara entropy dị elu mepụtara na-egosi ezigbo nchikota nke ihe eji arụ ọrụ (ike 1200 MPa, elongation 37%) ma nọrọ na mbụ mpaghara a na-enwetaghị na eserese nrụgide-elongation mkpụrụ. Na mgbakwunye na elongation dị ịrịba ama, ike siri ike na ike nke ihe mejupụtara HEA dị n'otu oke dị ka nnukwu iko ọla. Ya mere, a na-ekwere na mmepe nke elu-entropy composites nwere ike inyere aka nweta ihe magburu onwe Nchikota n'ibu Njirimara maka elu structural ngwa.
Mmepe nke elu entropy alloys bụ echiche ọhụrụ na-ekwe nkwa na metallurgy1,2. High entropy alloys (HEA) egosila n'ọtụtụ ọnọdụ ezigbo nchikota nke anụ ahụ na akụrụngwa, gụnyere nkwụsi ike dị elu nke thermal3,4 superplastic elongation5,6 ike ọgwụgwụ ike ọgwụgwụ7,8 corrosion resistance9,10,11, magburu onwe iyi resistance12,13,14 ,15 na tribological Njirimara15 ,16,17 ọbụna na elu okpomọkụ18,19,20,21,22 na n'ibu Njirimara na ala. okpomọkụ 23,24,25. Ngwakọta dị mma nke ihe eji arụ ọrụ na HEA na-ekwukarị na mmetụta anọ bụ isi, ya bụ nnukwu nhazi entropy26, distortion lattice siri ike27, ngwa ngwa diffusion28 na mmetụta mmanya29. A na-ekewakarị HEA dị ka ụdị FCC, BCC na HCP. FCC HEA na-enwekarị ihe mgbanwe dị ka Co, Cr, Fe, Ni na Mn ma na-egosipụta ọmarịcha ductility (ọbụlagodi na okpomọkụ dị ala25) mana ike dị ala. BCC HEA na-enwekarị ihe njupụta dị elu dị ka W, Mo, Nb, Ta, Ti na V ma nwee ike dị elu mana obere ductility na obere ike dị obere30.
Mgbanwe microstructural nke HEA dabere na igwe, nhazi thermomechanical na mgbakwunye nke ihe ka enyochala iji nweta ngwakọta kacha mma nke ihe eji arụ ọrụ. CoCrFeMnNi FCC HEA na-edobe nrụrụ rọba siri ike site na oke nrụgide dị elu, nke na-eduga n'ịba ụba siri ike (520 HV) na ike (1950 MPa), mana mmepe nke microstructure nanocrystalline (~ 50 nm) na-eme ka alloy brittle31. . Achọpụtala na ntinye nke ejima ductility (TWIP) na mgbanwe na-ebute plasticity (TRIP) n'ime CoCrFeMnNi HEAs na-enye ike siri ike na-arụ ọrụ nke ọma na-ebute ductility tensile dị elu, n'agbanyeghị na ọ na-efu ụgwọ ike ike n'ezie. N'okpuru (1124 MPa) 32. Nhazi nke microstructure oyi akwa (nke nwere obere oyi akwa na-adịghị mma) na CoCrFeMnNi HEA site na iji peening gbara égbè mere ka ọ dịkwuo ike, ma ọganihu a bụ nanị ihe dịka 700 MPa33. N'ịchọ ihe na nchikota kacha mma nke ike na ductility, mmepe nke multiphase HEAs na eutectic HEAs na-eji mgbakwunye nke ihe ndị na-abụghị isoatomic enyochala34,35,36,37,38,39,40,41. N'ezie, a chọpụtala na nkesa kachasị mma nke usoro siri ike na nke dị nro na eutectic high-entropy alloys nwere ike iduga nchikota nke ike na ductility35,38,42,43.
Sistemu CoCrFeNi bụ ihe a na-amụ nke ọma n'otu oge FCC elu-entropy alloy. Usoro a na-egosipụta ngwa ngwa na-arụsi ọrụ ike 44 na ezigbo ductility45,46 na ma ala na elu okpomọkụ. Emeela mgbalị dị iche iche iji meziwanye ike ya dị ntakịrị (~ 300 MPa) 47,48 gụnyere nchịkọta ọka25, microstructure dị iche iche49, ọdịda50,51,52 na mgbanwe-induced plasticity (TRIP)53. Nnụcha ọka nke nkedo cubic HEA CoCrFeNi nke nwere ihu site na ịse oyi n'okpuru ọnọdụ siri ike na-abawanye ike site na ihe dịka 300 MPa47.48 ruo 1.2 GPa25, mana na-ebelata mfu nke ductility site na ihe karịrị 60% ruo 12.6%. Mgbakwunye nke Al na HEA nke CoCrFeNi rụpụtara nguzobe nke microstructure dị iche iche, nke mụbara ike mkpụrụ ya ruo 786 MPa yana elongation ya ruru ihe dịka 22%49. Agbakwunyere CoCrFeNi HEA na Ti na Al iji mepụta ọnyà, si otú ahụ na-ewusi mmiri ozuzo ike, na-abawanye ike mkpụrụ ya ruo 645 MPa na elongation ruo 39%51. Usoro TRIP (mgbanwe cubic → hexahedral martensitic mgbanwe) na ejima mụbara ike tensile nke CoCrFeNi HEA ruo 841 MPa na elongation na nkwụsị ruo 76%53.
Emeela mbọ iji tinye mgbakwunye seramiiki na matrix cubic ihu HEA iji mepụta ngwakọta entropy dị elu nke nwere ike igosipụta nchikota nke ike na ductility ka mma. A na-edozi ihe ndị nwere entropy dị elu site na agụụ arc melting44, n'ibu alloying45,46,47,48,52,53, spark plasma sintering46,51,52, vacuum hot pressing45, hot isostatic pressing47,48 na mmepe nke usoro mmepụta ihe. 50. Carbides, oxides na nitrides dị ka WC44, 45, 46, Al2O347, SiC48, TiC43, 49, TiN50 na Y2O351 ka ejirila seramiiki nkwado na mmepe nke ihe mejupụtara HEA. Ịhọrọ matrix HEA ziri ezi na seramiiki dị mkpa karịsịa mgbe ị na-emepụta na ịmepụta ihe mejupụtara HEA siri ike ma dịgidere. N'ime ọrụ a, a họọrọ CoCrFeNi dị ka ihe matrix. Agbakwunyere SiC dị iche iche na CoCrFeNi HEA na mmetụta ha na microstructure, nhazi usoro na akụrụngwa a mụrụ.
Ngwongwo dị elu nke dị elu Co, Cr, Fe, na Ni (99.95 wt%) na SiC ntụ ntụ (99% dị ọcha, nha -400 mesh) n'ụdị nke elementrị bụ ihe eji eme ihe maka ịmepụta HEA composites. Ihe mejupụtara isoatomic nke CoCrFeNi HEA bụ nke mbụ etinyere n'ụdị ọla kọpa na-eme ka mmiri dị jụụ, wee wepụ ụlọ ahụ na 3 · 10-5 mbar. A na-ewebata gas argon dị ọcha iji nweta oghere achọrọ maka agbaze arc na tungsten electrodes na-adịghị eri nri. A na-atụgharị ingots nke si na ya pụta ma gbazee ugboro ise iji hụ na ịdị n'otu dị mma. A kwadebere ihe ndị mejupụtara entropy dị elu nke ụdị dị iche iche site na ịgbakwunye ụfọdụ SiC na bọtịnụ equiatomic CoCrFeNi, bụ nke megharịrị site na ntụgharị ugboro ise na agbaze na nke ọ bụla. Ebibiri bọtịnụ a kpụrụ akpụ sitere na ihe mejupụtara ya site na iji EDM maka nyocha na njirimara ọzọ. A kwadebere ihe nlele maka ọmụmụ ihe microstructural dịka usoro metallographic ọkọlọtọ siri dị. Nke mbụ, a na-enyocha ihe nlele ahụ site na iji microscope ìhè (Leica Microscope DM6M) yana ngwanrọ Leica Image Analysis ( Ọkachamara LAS Phase ) maka nyocha ọnụọgụ ọnụọgụ. Onyonyo atọ ewepụtara na mpaghara dị iche iche nwere mkpokọta ihe dịka 27,000 µm2 ka ahọpụtara maka nyocha usoro. E mere n'ụzọ zuru ezu ọmụmụ microstructural ọmụmụ, gụnyere chemical mejupụtara analysis na elementrị nkesa analysis, na-a rụrụ na a scanning eletrọn microscope (JEOL JSM-6490LA) nke nwere ike dispersive spectroscopy (EDS) analysis usoro. Emere njirimara nke nhazi kristal nke ihe mejupụtara HEA site na iji usoro mgbasa ozi X-ray (Bruker D2 phase shifter) na-eji isi iyi CuKα nwere ogo 0.04 °. A mụrụ mmetụta nke mgbanwe microstructural na akụrụngwa akụrụngwa nke ihe mejupụtara HEA site na iji ule microhardness Vickers na ule mkpakọ. Maka ule siri ike, a na-etinye ibu nke 500 N maka 15 s na-eji opekata mpe 10 indentations kwa ụdị. A na-eme ule mkpakọ nke ihe mejupụtara HEA n'ime ụlọ okpomọkụ na ụdị akụkụ anọ (7 mm × 3 mm × 3 mm) na igwe nyocha nke Shimadzu 50KN (UTM) na ọnụọgụ mbụ nke 0.001/s.
Ngwakọta entropy dị elu, nke a na-akpọ S-1 ruo S-6, kwadebere site na ịgbakwunye 3%, 6%, 9%, 12%, 15%, na 17% SiC (niile n'ịdị arọ%) na matrix CoCrFeNi. . n'otu n'otu. Ihe nrụtụ aka nke enweghị SiC agbakwunyere ka a na-akpọ ya ka ihe nlele S-0. E gosipụtara micrographs anya nke ihe mejupụtara HEA mepere emepe na fig. 1, ebe, n'ihi mgbakwunye nke ihe mgbakwunye dị iche iche, otu microstructure nke CoCrFeNi HEA gbanwere ka ọ bụrụ microstructure nke nwere ọtụtụ usoro nwere ọdịdị dị iche iche, nha na nkesa. Ọnụ ego nke SiC na nhazi. Ekpebiri ego nke usoro ọ bụla site na nyocha onyonyo site na iji sọftụ ọkachamara LAS Phase. Ntinye na eserese 1 (n'elu aka nri) na-egosi mpaghara ihe atụ maka nyocha a, yana akụkụ mpaghara maka akụkụ nke ọ bụla.
Micrographs anya nke ihe mejupụtara entropy dị elu mepere emepe: (a) C-1, (b) C-2, (c) C-3, (d) C-4, (e) C-5 na (f) C- 6. Ntinye ahụ na-egosi ihe atụ nke nsonaazụ nyocha usoro onyonyo dabere na iche site na iji sọftụ ọkachamara LAS Phase.
Dị ka e gosiri na fig. 1a, eutectic microstructure guzobere n'etiti mpịakọta matrix nke C-1 mejupụtara, ebe ọnụọgụ nke matrix na eutectic na-eme atụmatụ dị ka 87.9 ± 0.47% na 12.1% ± 0.51%, n'otu n'otu. Na ngwakọta (C-2) nke e gosiri na Fig. 1b, ọ dịghị ihe ịrịba ama nke mmeghachi omume eutectic n'oge siri ike, a na-ahụkwa microstructure kpamkpam dị iche na nke C-1 composite. Microstructure nke C-2 composite dị nnọọ mma ma mejupụtara efere dị nro (carbides) nke ekesara n'otu n'otu na usoro matrix (fcc). A na-eme atụmatụ akụkụ olu nke matriks na carbide na 72 ± 1.69% na 28 ± 1.69%, n'otu n'otu. Na mgbakwunye na matrix na carbide, a chọtara usoro ọhụrụ (silicide) na C-3 composite, dị ka e gosiri na Fig. 1c, bụ ebe a na-eme atụmatụ na akụkụ nke silicide dị otú ahụ, carbide na matrix na ihe dịka 26.5% ±. 0.41%, 25.9 ± 0.53, na 47.6 ± 0.34, n'otu n'otu. A na-ahụkwa usoro ọhụrụ (graphite) na microstructure nke C-4 composite; Achọpụtara ngụkọta nke usoro anọ. Usoro graphite nwere udi globular dị iche yana ọdịiche gbara ọchịchịrị na onyonyo anya ma ọ dị naanị na obere nha (ọnụego nha nha bụ naanị ihe dịka 0.6 ± 0.30%). N'ime ihe mejupụtara C-5 na C-6, ọ bụ naanị usoro atọ ka achọpụtara, na akụkụ graphite dị iche na nke gbara ọchịchịrị na ngwakọta ndị a na-apụta n'ụdị flakes. E jiri ya tụnyere flakes graphite dị na Composite S-5, flakes graphite dị na Composite S-6 dị obosara, dị mkpụmkpụ, na karịa mgbe niile. A hụkwara mmụba kwekọrọ na ọdịnaya graphite site na 14.9 ± 0.85% na C-5 mejupụtara ruo ihe dịka 17.4 ± 0.55% na C-6 mejupụtara.
Iji nyochaa n'ụzọ zuru ezu microstructure na kemịkalụ kemịkalụ nke oge ọ bụla na HEA composite, a na-enyocha ihe nlele site na iji SEM, na EMF point analysis na nke kemịkalụ a na-emekwa. E gosipụtara nsonaazụ C-1 mejupụtara na fig. 2, ebe ọnụnọ eutectic ngwakọta na-ekewapụ mpaghara nke isi matrix a na-ahụ nke ọma. E gosipụtara map kemịkalụ nke C-1 mejupụtara na Fig. 2c, ebe enwere ike ịhụ na Co, Fe, Ni, na Si na-ekesa n'otu n'otu na usoro matrix. Agbanyeghị, a chọtara obere Cr na usoro matriks ma e jiri ya tụnyere ihe ndị ọzọ nke isi HEA, na-atụ aro na Cr gbasapụrụ na matrik ahụ. Ngwakọta nke oge eutectic na-acha ọcha na foto SEM bara ụba na chromium na carbon, na-egosi na ọ bụ chromium carbide. Enweghị ihe dị iche iche SiC dị iche iche na microstructure, jikọtara ya na obere ọdịnaya nke chromium na matriks na ọnụnọ eutectic ngwakọta nwere akụkụ chromium-ọgaranya, na-egosi nbibi zuru oke nke SiC n'oge agbaze. N'ihi nbibi nke SiC, silicon na-agbaze na akụkụ nke matrix, na carbon free na-emekọ ihe na chromium iji mepụta chromium carbides. Dị ka a pụrụ ịhụ, ọ bụ nanị carbon ka usoro EMF kpebisiri ike nke ọma, a na-egosipụtakwa nguzobe nke usoro ahụ site n'ịchọpụta ọnụ ọgụgụ kasị elu carbide e ji mara na usoro mgbasa ozi X-ray.
(a) Foto SEM nke sample S-1, (b) onyonyo abawanyela, (c) maapụ elementrị, (d) nsonaazụ EMF n'ebe ndị egosiri.
E gosipụtara nyocha nke ihe mejupụtara C-2 na fig. 3. Dị ka ọdịdị anya na anya microscopy, nyocha SEM kpughere usoro dị mma nke nwere nanị akụkụ abụọ, na ọnụnọ nke obere lamellar dị mkpa nke na-ekesa na-ekesa na nhazi ahụ. akụkụ nke matrix, na enweghị usoro eutectic. Ihe nkesa nkesa na nyocha EMF nke oge lamellar kpughere ọdịnaya dị elu nke Cr (edo edo) na C (green) na nke a, nke na-egosikwa decomposition nke SiC n'oge agbaze na mmekọrịta nke carbon a tọhapụrụ na mmetụta chromium. . Matrix VEA na-etolite usoro carbide lamellar. Nkesa nke ihe na nyocha isi nke usoro matrix gosiri na ọtụtụ n'ime cobalt, ígwè, nickel na silicon dị na akụkụ nke matrix.
(a) Foto SEM nke sample S-2, (b) onyonyo abawanyela, (c) maapụ elementrị, (d) nsonaazụ EMF n'ebe ndị egosiri.
Ọmụmụ SEM nke ihe mejupụtara C-3 gosipụtara ọnụnọ nke usoro ọhụrụ na mgbakwunye na usoro carbide na matrix. Map elemental (Fig 4c) na EMF point analysis (Fig 4d) na-egosi na usoro ọhụrụ ahụ bara ụba na nickel, cobalt, na silicon.
(a) Foto SEM nke sample S-3, (b) onyonyo abawanyela, (c) maapụ elementrị, (d) nsonaazụ EMF n'ebe ndị egosiri.
E gosipụtara nsonaazụ nke nyocha SEM na EMF nke ihe mejupụtara C-4 na fig. 5. Na mgbakwunye na usoro atọ a hụrụ na C-3 mejupụtara, a chọpụtakwara ọnụnọ nke nodules graphite. Mpempe ụda olu nke akụkụ silicon-ọgaranya dịkwa elu karịa nke ihe mejupụtara C-3.
(a) Foto SEM nke sample S-4, (b) onyonyo abawanyela, (c) maapụ elementrị, (d) nsonaazụ EMF n'ebe ndị egosiri.
E gosipụtara nsonaazụ nke SEM na EMF ụdịdị S-5 na S-6 na ọnụ ọgụgụ 1 na 2. 6 na 7, n'otu n'otu. Na mgbakwunye na ọnụ ọgụgụ dị nta nke oghere, a hụkwara ọnụnọ nke flakes graphite. Ma ọnụ ọgụgụ nke flakes graphite na akụkụ olu nke akụkụ silicon nwere n'ime C-6 composite dị ukwuu karịa na C-5 mejupụtara.
(a) onyonyo SEM nke sample C-5, (b) nlele abawanyela, (c) maapụ elementrị, (d) nsonaazụ EMF n'ebe ndị egosiri.
(a) Foto SEM nke sample S-6, (b) onyonyo abawanyela, (c) maapụ elementrị, (d) nsonaazụ EMF n'ebe ndị egosiri.
E mekwara njirimara nhazi kristal nke ihe mejupụtara HEA site na iji nha XRD. E gosipụtara nsonaazụ ya na eserese 8. N'ụdị diffraction nke isi WEA (S-0), ọ bụ naanị ọnụ ọgụgụ kachasị elu kwekọrọ na oge fcc ka a na-ahụ anya. Usoro mgbasa ozi X-ray nke mejupụtara C-1, C-2, na C-3 gosipụtara ọnụnọ nke ọnụ ọgụgụ ndị ọzọ dabara na chromium carbide (Cr7C3), na ike ha dị ala maka ihe atụ C-3 na C-4, nke gosipụtara. nke ahụ nwekwara data EMF maka nlele ndị a. A na-ahụ ọnụ ọgụgụ kasị elu kwekọrọ na Co/Ni silicides maka ihe atụ S-3 na S-4, ọzọ na-adabere na nsonaazụ maapụ EDS gosiri na ọnụ ọgụgụ 2 na 3. Dị ka e gosiri na foto 3 na eserese 4. 5 na S-6 ọnụ ọgụgụ kasị elu hụrụ. kwekọrọ na graphite.
Ma njiri mara microstructural na crystallographic nke ihe mejupụtara emepụtara gosipụtara ire ere nke SiC agbakwunyere. Nke a bụ n'ihi ọnụnọ chromium na matrix VEA. Chromium nwere mmekọrịta siri ike maka carbon 54.55 ma na-emeghachi omume na carbon efu iji mepụta carbide, dị ka egosipụtara site na mbelata chromium nke matriks ahụ. Si gafere n'ime oge fcc n'ihi nkewa nke SiC56. Ya mere, mmụba na mgbakwunye nke SiC na isi HEA mere ka ọnụ ọgụgụ nke oge carbide na ọnụ ọgụgụ nke SiC n'efu na microstructure. Achọpụtara na a na-edobe Si nke a na matriks na obere mkpokọta (na S-1 na S-2), ebe ọ na-eme ka ọ bụrụ ihe dị elu (composites S-3 ka S-6) na-eme ka ọ bụrụ ihe mgbakwunye cobalt /. nickel silicide. Ọkọlọtọ enthalpy nke e guzobere Co na Ni silicides, nke enwetara site na ntinye aka kpọmkwem na calorimetry okpomọkụ dị elu, bụ -37.9 ± 2.0, -49.3 ± 1.3, -34.9 ± 1.1 kJ mol -1 maka Co2Si, CoSi na CoSi2, n'otu n'otu, ebe ndị a. ụkpụrụ bụ - 50.6 ± 1.7 na - 45.1 ± 1.4 kJ mol-157 maka Ni2Si na Ni5Si2, n'otu n'otu. Ụkpụrụ ndị a dị ala karịa okpomọkụ nke nhazi SiC, na-egosi na nkewa nke SiC na-eduga na nhazi nke Co/Ni silicides dị mma nke ukwuu. N'ime ma S-5 na S-6 mejupụtara, silicon ndị ọzọ na-efu efu dị, bụ nke etinyere n'ihe karịrị nguzobe silicide. Achọtala silicon a na-akwụghị ụgwọ ka ọ na-enye aka na graphitization a hụrụ na nchara nchara58.
A na-enyocha akụrụngwa nke ihe mejupụtara seramiiki emepụtara dabere na HEA site na nyocha mkpakọ na ule ike. A na-egosi akụkụ mgbakasị nrụgide nke ihe ndị mejupụtara mejupụtara na fig. 9a, na na Fig. 9b na-egosi nkwụsịtụ n'etiti ike mmepụta kpọmkwem, ike na-enye ike, ike siri ike, na elongation nke ihe ndị mepụtara.
(a) Mkpịsị aka na-agbakọ na (b) ihe mgbasa na-egosi nrụgide mkpụrụ pụrụ iche, na-enye ike, ike na elongation. Rịba ama na ọ bụ naanị ụdị S-0 ruo S-4 ka egosiri, ebe ụdị S-5 na S-6 nwere ntụpọ nkedo dị mkpa.
Dị ka a hụrụ na fig. 9, ike mkpụrụ sitere na 136 MPa maka isi VES (C-0) ruo 2522 MPa maka ihe mejupụtara C-4. E jiri ya tụnyere WPP bụ isi, ihe mejupụtara S-2 gosipụtara ezigbo elongation na ọdịda nke ihe dịka 37%, ma gosipụtakwa oke ike ike mkpụrụ (1200 MPa). Ngwakọta dị mma nke ike na ductility nke ihe mejupụtara a bụ n'ihi mmụba nke mkpokọta microstructure, gụnyere nkesa otu nke ezigbo carbide lamellae na microstructure niile, bụ nke a na-atụ anya na ọ ga-egbochi mmegharị nkwụsị. Ike mkpụrụ nke C-3 na C-4 mejupụtara bụ 1925 MPa na 2522 MPa, n'otu n'otu. Enwere ike ịkọwa ike ndị a dị elu site na oke dị elu nke simenti carbide na akụkụ silicide. Otú ọ dị, ọnụnọ nke usoro ndị a mekwara ka elongation na nkwụsịtụ nke naanị 7%. Usoro mgbakasị ahụ nke isi ihe mejupụtara CoCrFeNi HEA (S-0) na S-1 bụ convex, na-egosi ịgbalite mmetụta ejima ma ọ bụ TRIP59,60. Tụnyere ihe atụ S-1, usoro mgbakasị ahụ nke ihe nlele S-2 nwere ọdịdị concave na ụdị ihe dị ka 10.20%, nke pụtara na mgbakasị ahụ nkịtị bụ isi nrụrụ nke ihe nlele na steeti a nwere nkwarụ60,61. . Otú ọ dị, ọnụ ọgụgụ siri ike dị na ihe atụ a na-anọgide na-adị elu karịa nnukwu nsogbu, na n'ọnọdụ dị elu, a na-ahụkwa mgbanwe na convexity (ọ bụ ezie na a pụghị ịpụ na nke a bụ n'ihi ọdịda nke ibu mkpakọ mmanụ). ). Ngwakọta C-3 na C-4 nwere naanị plasticity nwere oke n'ihi ọnụnọ nke oke nha nke carbide na silicides na microstructure. Emereghị ule mkpakọ nke ihe atụ nke ihe mejupụtara C-5 na C-6 n'ihi nnukwu ntụpọ nkedo n'ụdị ihe ndị a mejupụtara (lee fig. 10).
Stereomicrographs nke nrụrụ nkedo (nke akụ na-acha uhie uhie gosipụtara) n'omume nke ihe mejupụtara C-5 na C-6.
E gosipụtara nsonaazụ nke ịle ike nke ihe mejupụtara VEA na fig. 9b. The isi WEA nwere ike nke 130 ± 5 HV, na sample S-1, S-2, S-3 na S-4 nwere ike ụkpụrụ nke 250 ± 10 HV, 275 ± 10 HV, 570 ± 20 HV na 755± 20 HV. Mmụba nke ike siri ike bụ nkwekọrịta dị mma na mgbanwe nke ike mkpụrụ nke enwetara site na ule mkpakọ ma jikọta ya na mmụba nke ọnụ ọgụgụ siri ike na ngwakọta. Ike mkpụrụ nke gbakọrọ agbakọ dabere na ebumnuche ebumnuche nke nlele ọ bụla ka egosiri na fig. 9b. N'ozuzu, a na-ahụ ihe kachasị mma nke ike mkpụrụ (1200 MPa), ike (275 ± 10 HV), na elongation na ọdịda (~ 37%) maka C-2 mejupụtara.
Ntụle nke ike ike na ikwu elongation nke mepụtara mejupụtara na ihe dị iche iche klaasị na-egosi na fig. 11a. Ngwakọta ndị dabere na CoCrFeNi na ọmụmụ ihe a gosipụtara elongation dị elu na ọkwa nrụgide ọ bụla enyere62. A pụkwara ịhụ na ihe ndị mejupụtara HEA na-emepụta n'ime ọmụmụ ihe a dị na mpaghara a na-ejighị n'aka na mbụ nke ibé ike mkpụrụ na elongation. Tụkwasị na nke ahụ, ihe ndị a na-emepụta ihe na-emepe emepe nwere nnukwu njikọ nke ike (277 MPa, 1200 MPa, 1925 MPa na 2522 MPa) na elongation (> 60%, 37%, 7.3% na 6.19%). Ike mbịakọta bụkwa ihe dị mkpa na nhọrọ nke ihe maka ngwa injinia dị elu63,64. N'akụkụ a, ihe mejupụtara HEA nke ihe a na-emepụta ugbu a na-egosipụta nchikota dị mma nke ike mkpụrụ na elongation. Nke a bụ n'ihi na mgbakwunye nke SiC njupụta dị ala na-arụpụta ihe mejupụtara nwere ike mkpụrụ dị elu. Ike mkpụrụ a kapịrị ọnụ na elongation nke ihe mejupụtara HEA dị n'otu oke dị ka HEA FCC na refractory HEA, dị ka egosiri na Fig. 11b. Ike ike na ike mkpụrụ nke ihe mejupụtara ndị mepere emepe dị n'otu ebe maka nnukwu iko ọla 65 (Fig 11c). A na-eji nnukwu iko ọla (BMS) mara oke ike na ike na-amịpụta, mana elongation ha nwere oke 66,67. Otú ọ dị, ike siri ike na ike nke ụfọdụ ihe mejupụtara HEA mepụtara na ọmụmụ ihe a gosikwara elongation dị ịrịba ama. Ya mere, e kwubiri na ngwakọta nke VEA mebere nwere ngwakọta pụrụ iche na nke a na-achọsi ike maka ngwa nhazi dị iche iche. Enwere ike ịkọwa nchikota pụrụ iche nke ihe eji arụ ọrụ site n'ụdị mgbasasị nke carbide siri ike kpụrụ na ọnọdụ na FCC HEA matrix. Otú ọ dị, dị ka akụkụ nke ihe mgbaru ọsọ nke inweta nchikota ka mma nke ike, microstructural mgbanwe microstructural na-esi na mgbakwunye na nke seramiiki adọ ga-eji nlezianya mụọ na ịchịkwa iji zere nkedo ntụpọ, dị ka ndị dị na S-5 na S-6 composites. ductility. okike.
Atụnyere nsonaazụ nke ọmụmụ a na ihe nhazi dị iche iche na HEAs: (a) elongation vesos ike mkpụrụ62, (b) nrụgide mkpụrụ dị iche iche na ductility63 na (c) na-enye ike megide ike65.
Ihe mejupụtara microstructure na akụrụngwa nke usoro ihe mejupụtara HEA-ceramic nke dabere na sistemụ HEA CoCrFeNi yana mgbakwunye SiC ka a mụọla wee nweta nkwubi okwu ndị a:
Enwere ike ịmepụta ihe ngwakọta entropy dị elu nke ọma site na ịgbakwunye SiC na CoCrFeNi HEA site na iji usoro agbaze arc.
SiC na-agbaze n'oge arc agbaze, na-eduga n'ichebe na ọnọdụ nke carbide, silicide na graphite phases, ọnụnọ na ọnụ ọgụgụ dị nta nke na-adabere na ọnụọgụ nke SiC agbakwunyere na isi HEA.
Ihe mejupụtara HEA na-egosipụta ọtụtụ ihe arụrụ arụ dị mma, nwere akụrụngwa dabara na mpaghara a na-ebubughị ya na ike mkpụrụ na atụmatụ elongation. Ike mkpụrụ nke ihe mejupụtara HEA ejiri 6 wt% SiC karịrị okpukpu asatọ karịa nke isi HEA ebe ọ na-ejigide 37% ductility.
Isi ike na ike mkpụrụ nke ihe mejupụtara HEA dị n'ogo nke nnukwu iko ọla (BMG).
Ihe nchoputa a na-egosi na ihe ndi ozo di elu-entropy alloy na-anọchite anya uzo di nma iji nweta ezigbo nchikota nke metal-mechanical Properties maka ngwa nhazi di elu.
Oge nzipu: Jul-12-2023