Imiterere yibikoresho (SMAs) bifite ibisubizo biranga deformisiyo kubitera imbaraga. Ubushyuhe bwa Thermomechanical buturuka ku bushyuhe bwo hejuru, kwimurwa, guhinduka gukomeye-gukomeye, nibindi (ubushyuhe bwo hejuru-icyiciro cyo hejuru cyitwa austenite, naho ubushyuhe buke bwo hasi bwitwa martensite). Inzibacyuho isubirwamo inshuro nyinshi biganisha ku kwiyongera gahoro gahoro, bityo uduce tutahinduwe bizagabanya imikorere ya SMA (bita umunaniro wimikorere) kandi bitange microcrack, amaherezo bizatera kunanirwa kumubiri mugihe umubare ari munini bihagije. Ikigaragara ni uko gusobanukirwa imyitwarire yumunaniro wubuzima bwibi bivanze, gukemura ikibazo cyibikoresho bihenze, no kugabanya iterambere ryibintu hamwe nuburyo bwo gukora ibicuruzwa byose bizabyara umuvuduko mwinshi mubukungu.
Umunaniro wa Thermo-mechanique ntabwo wigeze ukora ubushakashatsi kuri byinshi, cyane cyane kubura ubushakashatsi kubyerekeranye no gukwirakwiza umunaniro munsi ya mikorobe. Mugushyira mubikorwa hakiri kare SMA muri biomedicine, intego yibanze mubushakashatsi bwumunaniro nubuzima rusange bwintangarugero "zitagira inenge" munsi yimizigo yubukanishi. Mubisabwa hamwe na geometrie ntoya ya SMA, imikurire yumunaniro ntigira ingaruka nke mubuzima, ubushakashatsi rero bwibanda mukurinda gutangira aho kugenzura imikurire yacyo; mugutwara, kugabanya kunyeganyega no gukoresha ingufu zikoreshwa, birakenewe kubona imbaraga vuba. Ibice bya SMA mubisanzwe binini bihagije kugirango bikomeze gukwirakwizwa gukomeye mbere yo gutsindwa. Kubwibyo, kugirango wuzuze ibikenewe byokwizerwa hamwe numutekano, birakenewe gusobanukirwa neza no kugereranya imyitwarire yo gukura kunaniza binyuze muburyo bwo kwihanganira ibyangiritse. Gukoresha uburyo bwo kwihanganira ibyangiritse bishingiye kumyumvire yubukanishi bwavunitse muri SMA ntabwo byoroshye. Ugereranije nicyuma gakondo cyubatswe, kubaho kwinzibacyuho ihindagurika hamwe no guhuza imashini itera ibibazo bishya kugirango dusobanure neza umunaniro nuburemere bukabije bwa SMA.
Abashakashatsi bo muri kaminuza ya Texas A&M muri Reta zunzubumwe zunzubumwe zamerika bakoze ubushakashatsi bwikura ryumukanishi no gutwara umunaniro muri Ni50.3Ti29.7Hf20 superalloy kunshuro yambere, maze basaba ko amategeko agenga ingufu za Paris ashingiye kumurongo ashobora gukoreshwa muguhuza umunaniro. gukuramo umuvuduko wo gukura munsi yikintu kimwe. Dufatiye kuri ibi ko umubano ufatika hamwe niterambere ryikura rishobora gushyirwaho hagati yuburyo butandukanye bwo gupakira hamwe na geometrike, bishobora gukoreshwa nkibisobanuro bihuriweho byerekana imiterere yo gukura kwa SMAs. Impapuro zijyanye nazo zasohotse muri Acta Materialia ifite umutwe ugira uti "Ibisobanuro bihuriweho byerekana umunaniro ukabije wibikoresho bya mikorobe".
Ihuza ry'impapuro:
https://doi.org/10.1016/j.actamat.2021.117155
Ubushakashatsi bwerekanye ko iyo Ni50.3Ti29.7Hf20 alloy ikorewe ikizamini cya uniaxial tensile kuri 180 ℃, austenite ihindagurika cyane muburyo bwo guhangayika muke mugihe cyo gupakira, kandi modulus ya Young ni 90GPa. Iyo imihangayiko igeze kuri 300MPa Mu ntangiriro yo guhindura icyiciro cyiza, austenite ihinduka martensite iterwa no guhangayika; iyo gupakurura, martensite iterwa no guhangayika cyane cyane ihinduka rya elastique, hamwe na Modulus ya Young igera kuri 60 GPa, hanyuma igasubira muri austenite. Binyuze mu kwishyira hamwe, umuvuduko ukabije wubwiyongere bwibikoresho byubatswe byashyizwe mumategeko agenga ingufu za Paris.
Igishushanyo.1 BSE ishusho ya Ni50.3Ti29.7Hf20 imiterere yubushyuhe bwo hejuru yibuka hamwe no gukwirakwiza ingano ya oxyde
Igishushanyo 2 TEM ishusho ya Ni50.3Ti29.7Hf20 imiterere yubushyuhe bwo hejuru yibikoresho nyuma yo kuvura ubushyuhe kuri 550 ℃ × 3h
Igishushanyo cya 3 Isano iri hagati ya J na da / dN yumunaniro ukabije wa NiTiHf DCT kuri 180 ℃
Mu bushakashatsi bwakozwe muri iyi ngingo, byaragaragaye ko iyi formulaire ishobora guhuza umunaniro ukabije wubwiyongere bwikura ryikigereranyo uhereye kubushakashatsi bwose kandi ushobora gukoresha ibipimo bimwe. Amategeko agenga imbaraga m ni hafi 2.2. Isesengura ryavunitse ryumunaniro ryerekana ko gukwirakwiza imashini no gukwirakwiza ibinyabiziga ari ibice byavunitse, kandi kuba oxyde ya hafnium ikunze kuba byongereye imbaraga zo gukwirakwiza. Ibisubizo byabonetse byerekana ko amategeko agenga imbaraga imwe yingirakamaro ashobora kugera kubintu bisabwa muburyo butandukanye bwo gupakira ibintu no kugereranya geometrike, bityo bigatanga ibisobanuro bihuriweho n'umunaniro wa mikoro ya mikorobe yibikoresho byo kwibuka, bityo ukagereranya imbaraga zo gutwara.
Igishushanyo cya 4 SEM ishusho yo kuvunika kwa NiTiHf DCT nyuma ya 180 experiment igeragezwa ryumunaniro ukabije.
Igicapo 5 Kumeneka SEM ishusho ya NiTiHf DCT nyuma yo gutwara igeragezwa ryikura ryumunaniro uhoraho kubogama kwa 250 N
Muncamake, iyi mpapuro ikora ubukanishi bwuzuye kandi butwara umunaniro ukura kuri nikel-ikungahaye kuri NiTiHf yubushyuhe bwo hejuru bwububiko bwa mbere. Hashingiwe ku guhuza ibice, imbaraga zo mu bwoko bwa Paris zerekana imbaraga zo gukura zisabwa guhuza umuvuduko ukabije w’umunaniro wa buri igeragezwa munsi yikintu kimwe.
Igihe cyo kohereza: Sep-07-2021