Iqhaza lama-Rare Earth Elements ku-High-End 7xxx Series Ekhubazekile Alloys Aluminium

Ucwaningo olunzulu lwenziwe ekungezeni izakhi zomhlaba ezingavamile (REEs) ku-7xxx, 5xxx, kanye ne-2xxx uchungechunge lwe-aluminium alloys, okubonisa imiphumela ebonakalayo. Ikakhulukazi, ama-alloys angu-7xxx ochungechunge lwe-aluminium, aqukethe izakhi eziningi ze-alloying, ngokuvamile abhekana nokuhlukaniswa okunzima ngesikhathi sokuncibilika nokusakazwa, okuholela ekwakhekeni kwamanani abalulekile ezigaba ze-eutectic. Lokhu kunciphisa ukuqina nokumelana nokugqwala, kuphazamisa ukusebenza okuphelele kwe-alloy. Ukufakwa kwezinto ezingavamile zomhlaba kuma-alloys e-aluminium alloyed kakhulu kungacwengisa okusanhlamvu, kucindezele ukuhlukaniswa, futhi kuhlanze i-matrix, ngaleyo ndlela kuthuthukise i-microstructure kanye nezakhiwo zizonke.

Muva nje, uhlobo oluthile lwesicwengisisi sokusanhlamvu esiyiplastic esimangalisayo seluthole ukunakwa. Laba bacwengi basebenzisa izakhi zomhlaba ezingavamile ezifana no-La no-Ce ukuze bathuthukise ukuba buthaka kokusanhlamvu nemingcele yezinhlamvu ezingaphansi. Lokhu akucwengisisi kuphela okusanhlamvu kodwa futhi kukhuthaza ukuhlakazeka okufanayo kwemvula, kucindezela ukubuyiswa kwekristalu, futhi kuthuthukisa ngokuphawulekayo i-alloy ductility, ekugcineni kukhulise ukukhiqiza ezinqubweni ze-extrusion.

Ochungechungeni lwe-7xxx aluminiyamu alloys, izakhi zomhlaba ezingavamile ngokuvamile zengezwa ngezindlela ezintathu:

1.Izakhi zomhlaba ezingavamile zodwa;

2.Inhlanganisela ye-Zr nezinto ezingavamile zomhlaba;

3.Inhlanganisela ye-Zr, Cr, nezinto ezingavamile zomhlaba.

Inani eliphelele lezakhi zomhlaba ezingavamile ngokuvamile lilawulwa ngaphakathi kuka-0.1–0.5 wt%.

Izindlela Zezinto Ezingavamile Zomhlaba

Izakhi zomhlaba ezingavamile ezifana no-La, Ce, Sc, Er, Gd, no-Y zifaka isandla kuma-alloys e-aluminium ngokusebenzisa izindlela eziningi:

Ukucolisiswa okusanhlamvu: Izakhi zomhlaba ezingavamile zakha imvula esabalaliswe ngokufanayo esebenza njengezindawo ze-nucleation ehlukahlukene, eguqula izakhiwo ze-dendritic zibe izinhlamvu ezinhle ezilinganayo, okuthuthukisa amandla kanye ne-ductility.

Ukucindezelwa kokuhlukaniswa: Phakathi nokuncibilika nokuqinisa, izakhi zomhlaba ezingavamile zikhuthaza ukusatshalaliswa kwezakhi ezifanayo, zinciphisa ukwakheka kwe-eutectic, futhi andise ukuminyana kwe-matrix.

Ukuhlanzwa kwe-matrix: I-Y, i-La, ne-Ce ingasabela ngokungcola ekuncibilikeni (O, H, N, S) ukuze kwakhiwe izinhlanganisela ezizinzile, ukwehlisa okuqukethwe kwegesi nokufaka, okuthuthukisa ikhwalithi ye-alloy.

Ukuguqulwa kokuziphatha kokwenziwa kabusha kwekristalu: Izinto ezithile zomhlaba ezingavamile zingaphina imingcele yokusanhlamvu nezinhlamvana, zivimbele ukunyakaza kokugudluka kanye nokufuduka komngcele wokusanhlamvu. Lokhu kubambezela ukwenziwa kabusha kwekristalu futhi kulondoloza izakhiwo ezinhle ze-subgrain ngesikhathi sokucubungula okushisayo, kuthuthukisa kokubili amandla nokumelana nokugqwala.

Izinto Ezibalulekile Zomhlaba Ezingavamile kanye Nemiphumela yazo

I-Scandium (Sc)

I-Sc inerediyasi ye-athomu encane kunazo zonke phakathi kwezinto ezingavamile zomhlaba futhi iyinsimbi yoguquko. Isebenza kahle kakhulu ekuthuthukiseni izakhiwo ze-aluminium alloys ekhubazekile.

Kuma-alloys e-aluminium, i-Sc igxuma njenge-Al₃Sc ehambisanayo, ikhuphula izinga lokushisa lokwenziwa kabusha kwekristalu futhi icindezela ukukhohlela okusanhlamvu.

Uma ihlanganiswe ne-Zr, ifomu lezinhlayiya ezizinzile ezisezingeni eliphezulu ze-Al₃(Sc,Zr), ezikhuthaza izinhlamvu ezinhle ezilinganayo futhi zivimbele ukunyakaza kokugudluka kanye nokufuduka komngcele wokusanhlamvu. Lokhu kuthuthukisa amandla, ukumelana nokukhathala, nokusebenza kwe-stress-corrosion.

I-Sc ngokwedlulele ingase iholele ezinhlayiyeni ezimahhadla ze-Al₃(Sc,Zr), kwehlise ikhono lokwenza kabusha ikristalu, amandla, kanye ne-ductility.

I-Erbium (Er)

I-Er yenza ngendlela efanayo ne-Sc kodwa iyonga kakhulu.

Kuma-alloys ochungechunge lwe-7xxx, izengezo ezifanele ze-Er zicwengisa okusanhlamvu, zinqande ukunyakaza kokugudluka kanye nokufuduka komngcele wokusanhlamvu, cindezela ukuphinda kukhanye, futhi kuthuthukise amandla.

Uma ihlanganiswa ne-Zr, i-Al₃(Er,Zr) yenza izinhlayiya ezizinzile ngokwe-thermal kune-Al₃Er iyodwa, ehlinzeka ngokucindezelwa okungcono kwe-recrystallization.

I-Er eyeqile ingase ikhiqize izigaba ze-Al₈Cu₄Er, yehlise kokubili amandla ne-ductility.

I-Gadolinium (Gd)

Izengezo ezimaphakathi ze-Gd zicwenga okusanhlamvu, zikhuphule amandla kanye ne-ductility, futhi zithuthukisa ukunyibilika kwe-Zn, Mg, ne-Cu ku-matrix.

Umphumela wesigaba se-Al₃(Gd,Zr) ukhipha izikhonkwane kanye nemingcele ye-subgrain, ucindezela ukubuyiswa kabusha. Ifilimu esebenzayo iphinde yakheke ezindaweni zokusanhlamvu, okuqhubeka nokunciphisa ukukhula okusanhlamvu.

Ukweqisa kwe-Gd kungabangela ukuhwamuka kokusanhlamvu futhi konakalise izakhiwo zemishini.

I-Lanthanum (La), i-Cerium (Ce), ne-Yttrium (Y)

I-La icwenga okusanhlamvu, inciphisa okuqukethwe komoyampilo, futhi yakha ifilimu esebenzayo ezindaweni zokusanhlamvu ukuze ivimbele ukukhula.

I-La and Ce ikhuthaza indawo ye-GP kanye nemvula yesigaba, ithuthukisa amandla e-matrix nokumelana nokugqwala.

I-Y ihlanza i-matrix, ivimbela ukuhlakazwa kwezakhi ezinkulu zengxubevange ibe yisixazululo esiqinile, ithuthukisa i-nucleation, futhi inciphisa umehluko ongaba khona phakathi kwemingcele yokusanhlamvu nangaphakathi, ithuthukisa ukumelana nokugqwala.

Ukweqisa u-La, u-Ce, noma u-Y kungase kuholele ekuhlanganiseni okuqinile kwe-blocky, okunciphisa i-ductility namandla.

Izakhiwo zezinto ezinkulu zomhlaba ezingavamile kanye nezici zazo ku-aluminium