Dab tsi yog cov yam ntxwv ntawm nickel titanium alloy?
Nitinol, tseem hu ua Nitinol, yog cov khoom siv tshwj xeeb uas nthuav tawm cov khoom zoo siab vim nws qhov kev hloov pauv theem. Nitinol yog ib qho binary alloy uas muaj nickel thiab titanium. Qhov sib xyaw ntawm cov hlau muaj yuav luag sib npaug ntawm cov npib tsib xee thiab titanium, uas muab nws cov cim cim xeeb thiab cov khoom siv superelastic. Nitinol's theem transformation mechanism tshwm sim los ntawm kev sib raug zoo ntawm nws martensite thiab austenite siv lead ua qauv. Muaj ob theem sib txawv ntawm cov qauv siv lead ua vim qhov kev hloov pauv ntawm qhov kub thiab txias, uas yog theem austenite thiab martensite theem. Thaum lub alloy yog rhuab saum toj no ib tug tshwj xeeb kub hu ua transformation kub, nws transforms los ntawm qis-kub martensite theem mus rau high-temperature austenite theem. Nitinol kuj tuaj yeem ua rau rov qab hloov pauv, uas ua rau cov duab rov qab zoo thaum txias hauv qab qhov kev hloov pauv.
Theem transformation sequence ntawm nickel-titanium alloy thaum txias yog niam txiv theem (austenite theem) - R theem - martensite theem. R theem yog rhombus-zoo li tus, thiab austenite nyob rau hauv ib lub xeev thaum kub siab (ntau tshaj qhov kub ntawm austenite pib) los yog thaum lub load raug tshem tawm (sab nraud quab yuam tshem tawm Deactivation). Nws yog cubic thiab nyuaj. Cov duab yog qhov ruaj khov. Lub sijhawm martensite yog lub xeev thaum qhov kub thiab txias (tsawg dua Mf: qhov kub ntawm qhov martensite xaus) los yog thaum nws yog loaded (activated los ntawm sab nraud quab yuam). Nws yog hexagonal, ductile, repeatable, tsis ruaj khov, thiab yooj yim rau Deformation.
1. Cov nyhuv nco zoo
Ib qho ntawm cov khoom tseem ceeb ntawm Nitinol yog nws lub cim xeeb zoo, uas yog hais txog nws lub peev xwm nco qab nws cov duab qub thiab rov qab mus rau nws cov duab qub tom qab khoov thiab deformation. Qhov no txhais tau hais tias thaum lub alloy deforms ntawm qhov kub thiab txias (feem ntau hauv qab lub martensitic transformation kub), nws muaj peev xwm rov qab tau nws cov qub zoo thaum rhuab saum lub martensitic transformation kub. Cov cuab yeej no ua rau nws muaj txiaj ntsig zoo rau ntau yam kev siv nrog rau kev cog ntoo, aerospace thiab kev lag luam tsheb.
2. Zoo heev super elasticity
Nitinol kuj muaj superelasticity zoo heev, uas yog hais txog lub peev xwm rov qab mus rau nws qhov qub qub thaum khoov lossis ncab yam tsis muaj deformation mus tas li. Ntawd yog, muaj peev xwm tiv taus qhov deformation tseem ceeb thiab rov zoo tag nrho tom qab kev ntxhov siab. Qhov no tso cai rau cov hlau kom pom cov elasticity zoo nyob rau hauv cov kab mob siab, ib qho cuab yeej uas ua rau nws tsim nyog siv rau hauv cov neeg hlau, tshuab thiab cov cuab yeej uas xav tau siab elasticity thiab stability. Feem ntau siv nyob rau hauv teb xws li caij nplooj ntoos hlav ntsiab thiab anti-shock li.
⑴ Txoj Cai:
Lub superelasticity ntawm nickel-titanium alloys yog tshwm sim los ntawm martensitic theem transformation tam sim no nyob rau hauv nws cov qauv siv lead ua. Thaum qhov kub thiab txias, nickel-titanium alloys nyob rau hauv martensitic theem, thiab thim rov qab elastic deformation tuaj yeem tshwm sim rau lub sijhawm no. Thaum lub alloy yog stretched los yog khoov, ib theem hloov tshwm sim los ntawm martensite rau austenite. Thaum lub sij hawm tus txheej txheem no, lub alloy khoov los yog stretches, tab sis thaum lub load sab nraud raug tshem tawm, cov hlau rov qab mus rau nws cov thawj martensitic theem, ua tiav cov nyhuv superelastic yam tsis tas yuav deformation.
⑵ Cov kab mob:
Lub superelasticity ntawm npib tsib xee-titanium alloy muaj ntau hom kab mob, feem ntau txog li 8% mus rau ntau tshaj 10%. Qhov no ua rau nws muaj txiaj ntsig zoo hauv cov ntawv thov uas xav tau cov deformations loj thiab xav tau cov khoom siv los tswj nws cov qauv qub, xws li kev tsim cov khoom caij nplooj ntoos hlav, cov khoom siv tiv thaiv kev vibration, thiab lwm yam.
Tsis muaj yas deformation: Superelasticity tso cai rau npib tsib xee-titanium alloys elastically deform nyob rau hauv loj hom yam tsis ua rau deformation mus tas li. Qhov no tsis zoo li cov khoom siv hlau ib txwm siv, uas ua rau cov yas deformation mus tas li thaum lawv cov kev txwv tsis pub dhau.
⑶ Load-unload voj:
NiTi alloys nthuav tawm lub voj tseem ceeb thaum lub sij hawm thauj khoom-unloading cycles. Thaum lub sij hawm thauj khoom, cov hlau tau pom muaj kev sib raug zoo ntawm kev ntxhov siab, thaum lub sij hawm unloading txheej txheem, cov kev ntxhov siab poob sai heev, tsim ib tug pom tseeb voj. Qhov no yog vim cov nyhuv superelastic tshwm sim los ntawm kev hloov theem.
⑷ Cov nyhuv kub:
Superelastic zog muaj kev cuam tshuam zoo heev los ntawm qhov kub thiab txias. Theem transformation kub ntawm ib tug alloy tuaj yeem tswj tau los ntawm kev kho cov alloy muaj pes tsawg leeg kom tau raws li qhov yuav tsum tau ua haujlwm kub ntau hauv ib daim ntawv thov tshwj xeeb.
3. Lub cev sib xws:
Lwm cov cuab yeej tshwj xeeb ntawm Nitinol yog nws cov biocompatibility, uas txhais tau hais tias nws yog sib xws nrog cov ntaub so ntswg ntawm lub cev, ua rau nws zoo tagnrho rau siv hauv kev kho mob cog xws li stents thiab orthodontic xov hlau. Nitinol cov khoom tsis muaj tshuaj lom ua rau nws yog cov khoom siv zoo tshaj plaws rau kev cog qoob loo ib ntus thiab mus tas li, nrog rau kev siv tau zoo hauv orthopedics, phais plawv thiab neurosurgery.
Nitinol yog ib yam khoom tshwj xeeb thiab tshiab tau lees paub rau nws cov khoom tshwj xeeb xws li kev nco, superelasticity thiab biocompatibility. Cov khoom no ua rau nws muaj ntau yam khoom siv uas tuaj yeem siv rau hauv ntau qhov kev lag luam. Lub superelasticity ntawm nickel-titanium alloys yog dav siv nyob rau hauv cov khoom siv kho mob, aerospace, automotive industries thiab lwm yam kev lag luam, xws li nyob rau hauv kev tsim cov plawv stents, orthotics, shock-proof devices, thiab lwm yam.
Nitinol cov txheej txheem hloov theem yuav raug kawm txuas ntxiv mus, nws cov peev txheej thov yuav raug nthuav dav ntxiv, thiab Nitinol cov ntawv thov yav tom ntej yog qhov dav.
