Ucwaningo Lokumelana Nokugqwala Kwe-Hot dipped Galvalume Coating

I-Zn55Al1.6Si i-galvalume efakwe emanzini ashisayo isetshenziswe kabanzi emikhakheni eminingi efana nemboni yezimoto, ukwakhiwa kwemikhumbi, imboni yemishini njll, ngenxa nje yokusebenza kwayo okungcono kakhulu kokuqeda ukugqwala kune-Zinc enamathelayo, kodwa nangenxa yezindleko zayo eziphansi ( intengo ye-Al iphansi kunaleyo ye-Zn okwamanje). Imihlaba eyivelakancane efana ne-La ingavimbela ukukhula kwesikali futhi yandise ukunamathela kwesikali, ngakho-ke iye yaqashwa ukuvikela izinsimbi nezinye. metallic ama-alloys ngokumelene ne-oxidation nokugqwala. Kodwa-ke, kunezincwadi ezimbalwa kuphela ezishicilelwe ekusetshenzisweni kwe-La in hot dipped galvalume enamathela, futhi kuleli phepha imiphumela yokwengezwa kwe-La ekuphikiseni ukugqwala kwengubo ye-galvalume eshisayo yaphenywa.

Kusahlolwa

[1] Ukudipha okushisayo

I-Zn-Al-Si-La ingxube ye-alloy efakwe ngokushisayo equkethe u-0,0.02wt.%, 0.05wt.%, 0.1wt.% kanye no-0.2wt.% La isetshenziswe ku-Ф 1 mm intambo yensimbi ethambile. Inqubo yayimi kanje: ukuhlanza ukususa ukugqwala nokugcoba ngamagagasi aphakeme kakhulu (55 °C)→ukuhlanza ngamanzi→ ukuguquguquka(85°C)→ukoma (100~200 °C) ukudipha okushisayo(640~670 °C, 3 imizuzwana).

[2]Isivivinyo sokulahlekelwa isisindo

Ukuhlolwa kokuncipha kwesisindo kukalwe ngokuhlola isifutho se-acetic acid esisheshayo esine-acetic acid (CASS) nokuhlolwa kokucwiliswa kokugqwala okwenziwa egunjini lesifutho sikasawoti kanye nesisombululo se-NaCl esingu-3.5%. Ngemuva kokuhlolwa, imikhiqizo ebolayo yayisuswa ngezindlela zemishini, ihlanjululwe ngamanzi agelezayo, bese yomiswa ngomoya obandayo oqhumayo kanye nokuncipha kwesisindo kulinganiswa nge-electronic scale. Kuzo zombili izimo, ezintathu paralamasampuli enziwe ukuze athole imiphumela enembe kakhudlwana. Isikhathi sokuhlola sasingu-120 h sokuhlolwa kwe-CASS kanye namahora angu-840 sokuhlolwa kokucwiliswa.

[3]Ukuhlolwa kwe-Electrochemical

Ukuhlolwa kwe-electrochemical kwenziwa isiteshi somsebenzi samakhemikhali e-electrochemical i-IM6e esihlinzekwe yiJalimane, sithatha ipuleti leplatinamu njenge-electrode ephikisayo, i-calomel electrode egcwele njengereferensi ye-electrode, kanye ne-Zn-Al-Si-La enezintambo ezishisayo zensimbi ethambile njenge-electrode esebenzayo. I-corroding medium kwakuyisixazululo se-NaCl esingu-3.5%. Indawo engaphezulu evezwe kusixazululo sokuhlola yayiyi-1cm2. Izilinganiso ze-Electrochemical impedance spectroscopy (EIS) zenziwe ngebanga lefrikhwensi lasuka ku-10 kHz lafika ku-10 mHz, ububanzi besignali ye-sinusoidal voltage babungu-10 mV (rms).Amajika e-polarization abuthakathaka aqoshwa ebangeni likagesi ukusuka ku--70 mV kuya ku-70 mV, izinga lokuskena lalingu-1 mV/s. Kuzo zombili izimo, ukuhlola akuzange kuqale kwaze kwaba yilapho amandla okugqwala ehlala ezinzile (inguquko engaphansi kuka-5 mV emizuzwini emi-5).

[4]Izifundo ze-SEM ne-XRD

I-Surface morphologies yamasampula yahlolwa nge-SSX-550 scanning electron microscope (SEM) ngemva kokuhlolwa kokugqwala egumbini lesifutho sikasawoti kanye nesixazululo se-NaCl esingu-3.5%. Imikhiqizo yokugqwala eyakhiwe phezu kwamasampula esifutho sikasawoti kanye nesixazululo se-NaCl esingu-3.5% sahlolwa kusetshenziswa i-PW-3040160 X-ray diffraction (XRD).

Imiphumela nengxoxo

[1] Ukumelana nokugqwala
[1.1] Ukuncipha kwesisindo
I-Fig.1 ikhombisa imiphumela yokuhlolwa kokuncipha kwesisindo kukhabhinethi yesifutho sikasawoti kanye nesixazululo se-NaCl esingu-3.5%. Izinga lokugqwala lamasampula kuzo zombili izimo lehla okokuqala ngokwanda kokuqukethwe kwe-La kuze kufike ku-0.05wt.% bese lenyuka ngokwanda kokuqukethwe kwe-La. Ngakho-ke, ukumelana nokugqwala okungcono kakhulu kwatholakala ezingubo eziqukethe u-0.05wt.%La. Kutholwe ukuthi ngesikhathi sokuhlolwa kokucwiliswa, ukugqwala okubomvu kwatholwa kuqala kakhulu endaweni engu-0wt.%La enamathelayo kusixazululo se-NaCl esingu-3.5%, nokho, kuze kuphele ukuhlolwa kokucwiliswa, kwakungekho ukugqwala okubomvu endaweni engu-0.05wt.% .

2.1.2 Ukuhlolwa kwe-Electrochemical

I-Fig.2 ibonisa amajika e-polarization abuthakathaka we-Zn-Al-Si-La alloy coatings kusixazululo se-NaCl esingu-3.5%. Kungabonakala ukuthi ukuma kwamajika e-polarization abuthakathaka kubonise umehluko omncane, futhi inqubo yokugqwala yazo zonke izinhlobo ze-alloy coatings yayilawulwa ukusabela kwe-cathodic. Imiphumela efanelekile ye-Tafel esekelwe kuma-curve e-polarization abuthakathaka ku-Fig.2 inikezwa kuThebula 1. Ngokufanayo nokuhlolwa kokulahlekelwa kwesisindo, kuphinde kwatholakala ukuthi ukumelana nokugqwala kwe-galvalume coating kungathuthukiswa ngokungezwa okuncane kwe-La kanye nobuncane. izinga lokugqwala litholwe ngo-0.05wt.%La.

I-Fig.3 imele imidwebo ye-Nyquist erekhodelwe ukumbozwa ngamanani ahlukene we-La avezwe kusixazululo esingu-3.5% se-NaCl amahora angu-0.5. Kuzo zonke izimo, kwakukhona ama-arcs amabili ayesho izikhathi ezimbili ezihlala njalo. Le evela kumafrikhwensi aphezulu imele isici se-dielectric sengxube yengxubevange, kuyilapho leyo evamise ukuphansi ihambisana naleyo ye-substrate yensimbi ethambile ezimbotsheni (okungukuthi ukonakala kwe-Coating). Njengoba ukungezwa kwe-La kwanda, ububanzi be-arc imvamisa ephezulu buyakhula, lo mphumela wabonakala kakhulu uma kwenzeka i-Zn55Al1.6Si0.05La i-alloy coating. Ngokukhula okuqhubekayo kokuqukethwe kwe-La, nokho, ububanzi be-arc yefrikhwensi ephezulu yehla ngokuphambene. Phakathi naleso sikhathi, isikhungo sawo wonke ama-arcs sincike ku-quadrant yesine, okubonisa ukuthi umphumela wokuhlakazeka wenzeka endaweni ye-electrode.Ngaphansi kwalesi simo, imiphumela engcono ingatholakala ngokusebenzisa i-CPE (isici sesigaba esiqhubekayo) esikhundleni se-capacitance ehlanzekile eyaboniswa amanye amaqembu ocwaningo.