Kuyini Ukuzinza Kwezinga Lokushisa?

Ukuzinza kwezinga lokushisa kusho amandla wento noma wesistimu okugcina izakhiwo ezingashintshi kanye nokusebenza kuzo zonke izimo zokushisa ezihlukene. Lesi sici sinquma ukuthi into imelana kanjani nokuwohloka, izinguquko zobukhulu, noma ukuguqulwa kokusebenza lapho kuvezwe ukushisa noma ukubanda. Ukuzinza kwezinga lokushisa kukalwa ngokuqapha ukuchezuka kwezakhiwo ngokuhamba kwesikhathi emazingeni okushisa athile, ngokuvamile achazwa njengokuhluka kwephesenti ukusuka kumanani ayisisekelo.

Ukuzinza kwezinga lokushisa kusebenza ngesimiso sokuthi izinto ziba nezinguquko emzimbeni namakhemikhali lapho amandla okushisa eshintsha izakhiwo zamangqamuzana. Kuleveli ye-athomu, ukukhuphuka kwezinga lokushisa kubangela ukuthi amabhondi amamolekyuli adlidlizele kakhulu, okungase kuholele ekuqhekekeni kwebhondi noma ekumisweni kabusha.

Ukuzinza kwanoma iyiphi into kuncike emandleni awo okwenza kusebenze-emandleni amancane adingekayo ekuguquleni kwesakhiwo. Izinto ezisetshenziswayo ezinamandla okusebenza aphezulu zimelana nokuwohloka kokushisa ngokuphumelelayo. Isibonelo, izitsha zobumba ngokuvamile zibonisa ukuzinza okuphezulu kwezinga lokushisa uma kuqhathaniswa namapholymeri ngenxa yebhondi yawo eqinile ye-ionic ne-covalent.

Izindlela ezimbili eziyinhloko zibusa ukuqina kwezinga lokushisa: imiphumela ehlehliswayo (njengokunwetshwa kwezinga lokushisa) kanye nemiphumela engenakuhlehliswa (njengokubola noma ukuguquka kwesigaba). Izinguquko ezihlehliswayo zivumela izinto ukuthi zibuyele esimweni sazo sasekuqaleni lapho izinga lokushisa liba ngokwejwayelekile, kuyilapho ukuguqulwa okungahlehliseki kuguqule unomphela izici zentokozo.

Ama-coefficients okushisa alinganisa ukuthi izakhiwo zishintsha kanjani ngezinga lokushisa. Into ene-coefficient yezinga lokushisa engu-0.001/℃ihlangabezana noshintsho lwesakhiwo esingu-0.1% ngokuhlukahluka kwezinga lokushisa elingu-10 degree. Ama-coefficient aphansi abonisa ukuzinza okungcono.

Temperature Stability

I-Differential Scanning Calorimetry (DSC)isebenza njengezinga legolide lokuhlola ukuzinza kwe-thermal. Le nqubo ikala ukugeleza kokushisa kungene noma kuphume kusampula njengoba izinga lokushisa lishintsha ngenani elilawulwayo, ngokuvamile elingu-10 degree/min. I-DSC ihlonza amazinga okushisa okushintsha okubalulekile okuhlanganisa ukuguquka kwengilazi (Tg), indawo encibilikayo, nokuqala kokubola. Indlela ihlinzeka ngamavelu wamandla okwenza kusebenze ngokunemba ngaphakathi ±2%.

Ukuhlaziywa kwe-Thermogravimetric (TGA)ilandelela izinguquko ezinkulu ngaphansi kokushisisa okulawulwayo. Ucwaningo lwango-2024 olushicilelwe ku-Nature Communications lubonise ukuthi i-TGA ingathola amazinga okushisa okuqala okuwohloka anembe ukuya phakathi kuka-0.5 degree. Le nqubo ibonakala iwusizo ikakhulukazi ezintweni ezibola ngaphandle kokuncibilika okubonakalayo, njengama-polymers nezinhlanganisela.

Ukuhlolwa kokuguga kwe-Isothermalveza izinto ezisetshenziswayo emazingeni okushisa aphakeme angashintshi isikhathi eside-ngokuvamile amahora angu-1,000 kuya kwangu-10,000. Onjiniyela baqapha ukugcinwa kwezakhiwo ngezikhathi ezithile, bebala amanani okuwohloka ngezibalo ze-Arrhenius. Le ndlela ibikezela{7}}ukuzinza kwesikhathi eside kusukela kudatha-yesikhathi esifushane esheshisiwe.

Izicaciso zokuzinza kwezinga lokushisa ngokuvamile zibika amanani phakathi kwezikhathi ezimbili:-isikhathi esifushane (ihora elingu-1) nesikhathi eside{2}}(amahora angu-24 noma ngaphezulu). Ngobuchwepheshe be-elekthronikhi obunembayo, abakhiqizi bangacacisa ukuzinza njenge-±0.001℃esikhathini esinwetshiwe, kuyilapho izinto zasembonini zingavumela ukuhlukahluka kwempahla okungu-±5% kulo lonke ibanga labo lokusebenza.

Ukuqapha{0}}isikhathi sangempela sezinga lokushisaisebenzisa izinzwa ezishumekiwe ukulandelela ukuzinza ngesikhathi sokusebenza. Amasistimu athuthukisiwe asebenzisa ama-thermistors noma izitholi zokushisa zokumelana (ama-RTD) anezikhathi zokuphendula ezingaphansi kwama-millisecond angu-100, okuvumela ukulawula okunembayo ezinhlelweni ezidinga ukuzinza kwe-millidegree.

Ukwakheka kwamakhemikhalingokuyisisekelo inquma ukuziphatha okushisayo. Izinhlanganisela ze-Inorganic ngokuvamile zidlula izinto eziphilayo{1}}i-aluminium oxide igcina ukuqina kuye ku-1,800℃, kuyilapho amapholymer amaningi e-organic ehla ngaphansi kuka-400 degree. Ukuba khona kwamabhondi angagcwele, izakhiwo ezinephunga elimnandi, noma ama-heteroatom kuthonya kakhulu izindlela zokubola.

Izakhiwo zamangqamuzanaidlala indima ebalulekile. Ama-polymers axhumene abonisa ukuzinza okuthuthukisiwe uma kuqhathaniswa namaketango amugqa ngenxa yokuthi izixhumanisi zikhawulela ukunyakaza kwamangqamuzana. Ucwaningo lwango-2023 ku-Advanced Materials luthole ukuthi ukwanda kokuminyana kwe-crosslink kusuka ku-10% kuya ku-30% kuthuthukisa ukuzinza kwe-thermal cishe ngama-degree angama-60 kuma-epoxy resins.

Isimo se-ambientkunomthelela omkhulu emazingeni okuwohloka. Izimo ze-oxidative zisheshisa ukuwohloka{1}}izinto ezizinze ku-300℃ku-nitrogen zingase zehluleke ku-200℃emoyeni. Ezinye izinhlelo zokusebenza zidinga umoya ongasebenzi kahle noma izimo zevacuum ukuze kugcinwe ukuzinza emazingeni okushisa aphakeme.

Okuqukethwe umswakamakuthinta kokubili ukuzinza ngokomzimba namakhemikhali. Ama-molecule wamanzi angadala ukusabela kwe-hydrolysis noma aguqule amazinga okushisa esigaba. Izinto ezisetshenziswa ekwenzeni imithi ngokuvamile zidinga isitoreji esingaphansi kwamadigri angu-25 ngomswakama ongaphansi kuka-60% ukuze kugcinwe ukuzinza.

Ukucindezeleka komshinikuhlanganiswe nezinga lokushisa kudala imiphumela yokuwohloka kwe-synergistic. Izinto ezingaphansi komthwalo oqinile zibonisa ukuzinza okuphansi kwe-thermal kunezibonelo ezingacindezelwe. Lesi simo siba sibucayi ekusetshenzisweni kwesakhiwo lapho izingxenye ngesikhathi esisodwa zithola ukulayisha okushisayo nokokusebenza.

Imvamisa yokuhamba ngebhayisikili eshisayokubaluleke kakhulu njengezinga lokushisa eliphelele. Ingxenye ekwazi ukumelana nedigri engu-100 engashintshi ingase yehluleke lapho igijinyiswa phakathi kwamadigri angu-25 no-100 ngokuphindaphindiwe ngenxa yokukhathala okushisayo. Inani lemijikelezo eya ekuhlulekeni lilandela -ubudlelwane bomthetho nobukhulu bokuhluka kwezinga lokushisa.

Temperature Stability

Izingxenye ze-elekthronikhi zikhiqiza ukushisa okukhulu ngesikhathi sokusebenza, okwenza ukuzinza kwezinga lokushisa kube okuhamba phambili ekuthembekeni. Ama-microprocessors esimanje akhiqiza ukushisa okungaphezu kuka-100 W/cm², okudinga izinto ezigcina ukusebenza kusuka -kusuka ku-40 kuya ku-125℃. Ama-semiconductors asekelwe ku-silicon abonisa ukuzinza kwemvelo okuhle kakhulu, ngokukhukhuleka okuncane kulo lonke leli banga.

I-Power electronics ibhekana nezimo ezinzima nakakhulu. Ama-IGBT nama-MOSFET ezimotweni zikagesi kufanele asebenze ngendlela ethembekile emazingeni okushisa okuhlangana afinyelela ku-175 degree. Izinto zokupakisha ezithuthukisiwe ezinama-coefficients okushisa angaphansi kuka-50 ppm/degree ziqinisekisa ukuthi izici zikagesi zihlala ngaphakathi kokucaciswa naphezu kokuhlukahluka kokushisa.

Ukungazinzi kwezinga lokushisa kuma-elekthronikhi kubonakala njengokukhukhuleka kwepharamitha, ukukhuphuka kokuvuza kwamanje, namaphutha esikhathi. Ukwenyuka kwezinga lokushisa okungu-10℃kungaphinda kabili ukuvuza kwamanje kwe-semiconductor, kuthinte ukusetshenziswa kwamandla futhi kubangele ukungasebenzi kahle kwesekethe. Amasistimu okuphatha okushisayo asebenzisa izinto zokushintsha isigaba manje agcina uzinzo ngaphakathi kwe-±2℃ngisho nangaphansi komthwalo oguqukayo womsebenzi.

Ibhethri le-lithium ion limelela obunye bobuchwepheshe-obuzwela kakhulu bokugcina amandla. Lawa mabhethri asebenza kahle kakhulu phakathi kuka-15℃no-35℃, nokusebenza kwehla isithunzi ngokushesha ngaphandle kwaleli windi. Ukuzinza kwezinga lokushisa kuthinta ngokuqondile umthamo webhethri, impilo yomjikelezo, nokuphepha.

Emazingeni okushisa aphansi angaphansi kuka-0 degree, ama-electrolyte ebhethri ye-lithium ion aba yi-viscous, ehlisa ngokuphawulekayo ukuqhutshwa kwe-ionic. Amandla angehla ngo-30% noma ngaphezulu kokuthi -20℃. Okubaluleke nakakhulu, ukushaja emazingeni okushisa aqandayo kubeka engcupheni idiphozi ye-lithium plating-metallic ku-anode enciphisa unomphela umthamo futhi ingabangela amasekhethi amafushane angaphakathi.

Amazinga okushisa aphezulu angaphezu kuka-45 degrees asheshisa izindlela zokuwohloka kwamabhethri e-lithium ion. Kukho konke ukukhuphuka okungu-10 okungaphezu kwebanga elifanele, impilo yomjikelezo ngokuvamile yehla ngo-50%. Kuma-degree angama-60 nangaphezulu, ukubola kwe-electrolyte kuyashesha, kukhiqize igesi ekhulisa umfutho weseli. I-Thermal Runaway{7}}i-exothermic reaction engalawuleki{8}}iba yingozi enkulu engaphezu kuka-80 degree.

Amasistimu okuphatha ibhethri athuthukisiwe aqapha amazinga okushisa eseli anemba ±1℃, ukupholisa okusebenzayo noma ukushisisa ukuze kugcinwe iwindi lokusebenza elamukelekayo. Isakhiwo sokuphatha okushisayo kwe-Tesla, isibonelo, sisebenzisa izihibe zokupholisa ze-glycol ukuze kugcinwe amaphakethe ebhethri ngaphakathi kwamadigri angu-5 wezinga lokushisa eliqondiwe ngesikhathi sokushaja nokukhipha.

Izingxenye zendiza zibekezelela ukuhlukahluka kwezinga lokushisa okwedlulele, ukusuka -ku-55℃at cruise altitude ukuya ku-200℃+ eduze kwezinjini. Ama-Titanium alloy nama-nickel{5}based superalloys asebenza{8}}ezindaweni zokushisa eziphezulu ngenxa yekhono lawo lokugcina izakhiwo zemishini ezingaphezu kuka-600℃. Lezi zinto zokusebenza zihlolwa kanzima ngamazinga e-AEC-Q100, okuqinisekisa ukuzinza ngo-1,{11}} womjikelezo wokushisa.

Izinto eziyinhlanganisela kuma-airframe kumele zigcine ukuzinza kwe-dimensional kuyo yonke imvilophu yendiza. Izinhlanganisela ze-carbon fiber epoxy zibonisa ama-coefficients okunweba okushisayo angu-0.5-2 ppm/degree ahambisana namafayibha-izikhathi ezingaphansi kuka-50 ngaphansi kwe-aluminium. Lokhu kuzinza kuvimbela ukuhlanekezela okushisayo okungase kuthinte i-aerodynamics noma ubuqotho besakhiwo.

Ama-reactors amakhemikhali ngokuvamile asebenza emazingeni okushisa aphakeme lapho ukuqina kokushisa kunquma ukuphepha kwenqubo. Ukusabela kwe-exothermic kudinga izinto ezimelana nokubola ngaphansi kwezimo ezivamile nezicasukile. Ukuhlolwa kokuzinza kwe-thermal kukhomba izinga lokushisa eliphezulu eliphephile lokusebenza futhi kunikeza idatha yokuklama isistimu yokusiza.

Uketshezi lokudlulisa ukushisa olujikeleza ngezinhlelo zezimboni kumele lumelane nokuqhekeka okushisayo. Uketshezi lwesimanje lokwenziwa luhlala luzinzile luze lufike ku-350℃+, uma luqhathaniswa no-250℃lwamafutha amaminerali avamile. Lobu bubanzi obunwetshiwe bunika amandla ukudluliswa kokushisa okuphumelelayo futhi kunciphisa imvamisa yokulungisa.

Ukuwohloka kokubalulekile okuvela ekuzinzeni okunganele kwezinga lokushisa kubonakala kuzo zonke izindlela zokuhluleka eziningi. Ukubola okushisayo kukhiqiza imikhiqizo eshintshashintshayo eshintsha ukwakheka kwamakhemikhali futhi idale izikhala ezintweni eziqinile. Lezi ziphambeko zesakhiwo ziyanda, ekugcineni zidale ukwehluleka kwemishini.

Kuma-polymers, i-chain scission kunciphisa isisindo samangqamuzana, kunciphisa amandla okudonsa kanye nokwanda kokuqina. Ucwaningo lwango-2024 lwalandelela ukuwohloka kwe-polyethylene ku-120 degree, kubheka ukulahlekelwa amandla okungu-40% ngemva kwamahora angu-500. I-oxidation ibhebhethekisa le nqubo, yenze amaqembu e-carbonyl aqhubekisela phambili ukuwohloka.

Ukungaqini kwe-Dimensional kubangela izinkinga ezibucayi ezinhlelweni zokusebenza ezinembayo. Izingxenye ze-Optical ezithola ukwanda okushisayo okungaphezu kokubekezelelwa kwedizayini zilahlekelwa ukugxila noma ukuqondanisa. I-coefficient engu-1 ppm/℃yokunwetshwa kwe-thermal ihumusha ku-10 μm ushintsho lwe-dimensional imitha ngayinye ngokushintshashintsha kwezinga lokushisa elingu-10 degree{5}}okwanele ukufaka engozini{6}}amasistimu amaningi anemba aphezulu.

Ukwehluleka kwe-elekthronikhi okuvela ekungazinzini kokushisa kufaka phakathi amaphutha esikhathi, izinkinga zesignali yobuqotho, nokulimala unomphela. Amajoyinti e-solder abhekana nokuhamba ngebhayisikili okushisayo okuphindaphindiwe aba nokuqhekeka kokukhathala, okwandisa ukumelana nogesi kuze kube yilapho evuleka{1}}ukwehluleka kwesekethe. Ucwaningo lubonisa impilo ehlangene ye-solder ilandela ubudlelwano be-Coffin-kaManson, nemijikelezo eya ekuhlulekeni ngokuphambanayo ngokulingana ne-thermal strain amplitude.

Izingozi zokuphepha ziyavela lapho imikhawulo yokuqina kokushisa kweqiwa. Ukusabela kwe-Runaway exothermic ezinqubweni zamakhemikhali kungabangela ukuqhuma. Ukugijima kwebhethri okushisayo kukhiqiza amazinga okushisa angaphezu kuka-800 degree, kanye nokukhiqizwa kwegesi evuthayo. Ukuphatha okushisayo okufanelekile okusekelwe kudatha enembile yokuzinza kuvimbela ukwehluleka okunjalo okuyinhlekelele.

Imithelela yezomnotho yokuzinza okunganele kwezinga lokushisa ihlanganisa ukuncishiswa kwesikhathi sokuphila kwemishini, ukukhuphuka kwezindleko zokunakekela, nokulahlekelwa kokukhiqiza. Izikhungo ezisebenza eduze kwemikhawulo yokushisa okubalulekile zihlangabezana nokuguga okusheshisiwe, okungase kudinge ukushintshwa kwengxenye iminyaka ngaphambi kwempilo yedizayini. Imboni kawoyela negesi ilinganisela ukuthi ukusimama okushisayo okuthuthukisiwe oketshezini lokumba kunganciphisa izindleko zesikhathi sokuphumula ngo-$500M+ ngonyaka.

Temperature Stability

Ama-electronics omthengi ngokuvamile asebenza ngokuphephile phakathi kuka-0℃no-45℃, nakuba amazinga okushisa esitoreji anganwebeka ukusuka -ku-20℃kuya ku-60℃. Izinto zikagesi zezimboni nezezimoto zidinga ububanzi obubanzi, ngokuvamile -40℃kuya ku-85℃ukuze zisebenze kanye -55℃kuya ku-125℃ukuze zigcinwe. Ama-elekthronikhi akhethekile asezingeni eliphezulu okushisa kwe-aerospace noma i-downhole izicelo angase asebenze ngokuthembekile ngaphezu kwamadigri angu-200 kusetshenziswa ama-semiconductors e-silicon carbide kanye nokupakishwa kwe-ceramic.

Amasu amaningana athuthukisa ukuzinza kokushisa. Ukwandisa ukuminyana kwe-crosslink kuma-polymers kukhawulela ukunyakaza kwamangqamuzana futhi kuphakamisa izinga lokushisa lokubola. Ukwengeza ama-fillers azinzile njengezinhlayiya ze-ceramic kuthuthukisa ukumelana nokushisa kwezinto eziyinhlanganisela. Ukuguqulwa kwamakhemikhali njengokufaka izindandatho ezinephunga elimnandi noma amaqembu afakwe fluorinated kukhulisa amandla ebhondi. Ezinsimbi, izakhi ze-alloying zakha izendlalelo ze-oxide ezizinzile ezivikela ngokumelene ne-oxidation emazingeni aphezulu okushisa. Ubuchwepheshe bokumboza busebenzisa izendlalelo ezivikelayo ezincanyana ezinweba ububanzi bokusebenza bezinto eziyisisekelo.

Yebo, ukuwohloka kokushisa ngokuvamile kubangela izinguquko ezingenakuhlehliswa. Ukweqa amazinga okushisa abalulekile kungabangela ukubola kwamakhemikhali, ukuguqulwa kwesigaba, noma izinguquko ze-microstructural ezishintsha unomphela izakhiwo zezinto ezibonakalayo. Kodwa-ke, izinto ezihlangabezana nemiphumela engokomzimba kuphela njengokunwetshwa kwezinga lokushisa ngokuvamile ziyalulama lapho izinga lokushisa liba ngokwejwayelekile. Umehluko usekutheni amabhondi amakhemikhali ayaphuka yini ngesikhathi sokushisisa. Lapho amangqamuzana esebolile, ukubuyela emazingeni okushisa aphansi akukwazi ukuhlehlisa umonakalo.

I-Aerospace nezinhlelo zokuvikela zidinga ukuqina okushisayo okukhethekile, ngezinto ezisebenza kuwo wonke amazinga okushisa angama-250 + degrees. Imboni kawoyela negesi idinga ukuzinza ezindaweni ezinomgodi ophansi ezidlula ama-degree angu-200 ngezingcindezi ezingaphezu kuka-25,000 psi. Ukukhiqiza amandla enuzi kusebenzisa izinto ezizinze ku-500℃+ isikhathi eside. Izinqubo ezithuthukisiwe zokukhiqiza ezifana nokufakwa komhwamuko wamakhemikhali zisebenza ku-1,000℃+, ezidinga ama-substrates kanye nezinto zokusebenza ezinokuzinza okwedlulele okushisayo. Izinhlelo zokusebenza zesikhala zibhekana nokweqisa okubanzi kakhulu, kusukela ku--270℃in shadow ukuya ku-+120℃ekukhanyeni kwelanga okuqondile.

Ukuzinza kwezinga lokushisa kukhawulela ngokuyisisekelo ukuthi izinto zingatshalwa kuphi futhi kanjani. Ukuqonda izici ezithinta ukuziphatha okushisayo{1}}kusuka ekuhlanganisweni kwamangqamuzana kuya kwezimo zemvelo{2}}kwenza onjiniyela bakwazi ukukhetha izinto ezifanele futhi baklame amasistimu okuphatha okushisayo asebenzayo. Njengoba izinhlelo zokusebenza ziphushela ekuminyaneni okuphezulu kwamandla nasezimweni eziqinile, ukuthuthuka kwezinga lokushisa{4}}izinto ezizinzile nezindlela zokulinganisa ziyaqhubeka nokwandisa lokho okunokwenzeka ngokobuchwepheshe.

Ukuphambana kokuqina kwe-thermal nezinye izinto ezibonakalayo kudala ukuhwebelana kwedizayini eyinkimbinkimbi. Impahla ingase inikeze ukuzinza okuhle kakhulu kwezinga lokushisa kodwa amandla okusebenza angenamandla, noma okuphambene nalokho. Impumelelo idinga ukulinganisa izimfuneko eziningi kuyilapho kuhlonishwa izithiyo ezibalulekile ezibekwa i-thermal physics.