Umahluko phakathi kwegalvanizing, cadmium plating, chrome plating, kunye nenickel plating

Gukusindisa

Iimpawu:

I-Zinc izinzile kumoya owomileyo kwaye ayiguquki lula. Kwimimandla yamanzi kunye nomswakama, isabela nge-oksijeni okanye i-carbon dioxide ukuze yenze i-oxide okanye i-alkaline zinc carbonate films, ezinokuthintela i-zinc ukuba iqhubeke i-oxidize kwaye inikeze ukhuseleko.

I-Zinc ichaphazeleka kakhulu kukuhlwa kwi-asidi, i-alkali, kunye ne-sulfide. Umaleko owenziwe igalvanized ngokubanzi ufuna ukunyangwa. Emva kokudlula kwi-chromic acid okanye isisombululo se-chromate, ifilimu ye-passivation eyenziweyo ayivezwa lula emoyeni ofumileyo, iphucula kakhulu amandla ayo okuchasa ukubola. Kwiindawo zentwasahlobo, iindawo ezinodonga oluncinci (ubukhulu bodonga <0.5m), kunye neentsimbi zetsimbi ezifuna amandla aphezulu omatshini, ukukhutshwa kwe-hydrogen kufuneka kuqhutywe, ngelixa ubhedu kunye nobhedu lwe-alloy lungenakufuna ukususwa kwe-hydrogen.

Ukwenza igalvanizing kuneendleko eziphantsi, ukusetyenzwa lula, kunye nesiphumo esihle. Ubunakho obuqhelekileyo be-zinc bune-negative, ngoko ke ukugquma kwe-zinc kukugquma kwe-anodic kwiintsimbi ezininzi.

I-galvanization isetyenziswa ngokubanzi kwiimeko ze-atmospheric kunye nezinye iindawo ezifanelekileyo. Kodwa ayifanelekanga ukusetyenziswa njengenxalenye yefriction.

Cchrome plating

Iimpawu: Kwiindawo ezidibana nomoya wolwandle okanye amanzi olwandle, nakumanzi ashushu angaphezu kwama-70.℃, i-cadmium plating izinzile ngokwentelekiso, inokumelana ne-corrosion eyomeleleyo, ukuthambisa okulungileyo, kwaye inyibilika kancinane kwi-dilute hydrochloric acid, kodwa inyibilika kakhulu kwi-nitric acid kwaye ayinyibiliki kwialkali. Ioksidi yayo nayo ayinyibiliki emanzini. I-Cadmium yokwambathisa ithambile kune-zinc, kunye ne-hydrogen embrittlement encinci kunye nokuncamathela okunamandla.

Ngaphaya koko, phantsi kweemeko ezithile ze-electrolytic, i-cadmium coating efunyenweyo ithandeka ngakumbi kunobuhle be-zinc. Kodwa igesi eveliswa yicadmium ngexesha lokunyibilika inetyhefu, kwaye iityuwa zecadmium ezinyibilikayo nazo zinetyhefu. Ngaphantsi kweemeko eziqhelekileyo, i-cadmium isebenza njengengubo ye-cathodic kwintsimbi kunye ne-anodic coating ku-oceanic kunye nobushushu obuphezulu.

Isetyenziswa ikakhulu ukukhusela iinxalenye kwi-atmospheric corrosion ebangelwa ngamanzi olwandle okanye izisombululo zetyuwa ezifanayo, kunye nomphunga wamanzi olwandle. Iindawo ezininzi kwimizi-mveliso yeenqwelomoya, zaselwandle, nezombane, iziphethu, kunye neenxalenye ezinemisonto zifakwe i-cadmium. Inokupholiswa, i-phosphated, kwaye isetyenziswe njengesiseko sepeyinti, kodwa ayinakusetyenziswa njengesixhobo.

Ukucwenga kweChromium

iimpawu:

I-Chromium izinzile kakhulu kwi-atmospheres efumileyo, i-alkaline, i-nitric acid, i-sulfide, i-carbonate solutions, kunye ne-organic acids, kwaye i-soluble ngokulula kwi-hydrochloric acid kunye ne-acid concentrated sulfuric acid. Ngaphantsi kwesenzo sangoku ngokuthe ngqo, ukuba i-chromium layer isebenza njenge-anode, i-soluble ngokulula kwisisombululo se-caustic soda.

Umaleko wechromium unokuqina okuqinileyo, ubunzima obuphezulu, i-800-1000V, ukumelana nokunxiba kakuhle, ukubonakaliswa kokukhanya okuqinileyo, kunye nokumelana nobushushu obuphezulu. Ayitshintshi umbala ongaphantsi kwama-480℃, iqala ukuba ne-oxidize ngaphezulu kwe-500℃, kwaye kunciphisa kakhulu ubunzima kwi-700℃. Ukungalungi kwayo kukuba ichromium iqinile, intsonkothe, kwaye ithande ukuqhawuka, ngakumbi xa iphantsi kwemithwalo yempembelelo etshintshanayo. Kwaye ine-porosity.

Isinyithi seChromium sithambekele ekugqithiseni emoyeni, okukhokelela ekwenziweni kwefilimu ye-passivation kwaye ngaloo ndlela kutshintshe amandla echromium. Ke ngoko, ichromium iba yicathodic coating kwintsimbi.

Akulungele ukusebenzisa i-chrome plating ngqo njenge-anti-corrosion layer phezu kwendawo yentsimbi. Ngokubanzi, i-electroplating ye-multi-layer (oko kukuthi i-copper plating→i-nickel plating→chromium plating) iyafuneka ukuze kuphunyezwe injongo yomhlwa

ukuthintela kunye nokuhombisa. Okwangoku isetyenziswa ngokubanzi ekuphuculeni ukuxhathisa ukunxitywa kwamalungu, ukulungisa imilinganiselo, ukubonakaliswa kokukhanya, kunye nezibane zokuhombisa.

I-Nickel plating

iimpawu:

I-Nickel inozinzo olululo lweekhemikhali kwi-atmosfera kunye nesisombululo se-alkaline, ayiguquki lula, kwaye i-oxidized kuphela kumaqondo obushushu angaphezu kwama-600.° C. Inyibilika kancinane kwi-asidi yesulfuric kunye ne-hydrochloric acid, kodwa inyibilika ngokulula kwi-dilute nitric acid. Igqithiswa ngokulula kwi-asidi ye-nitric egxininisiweyo kwaye ngenxa yoko inoxhathiso oluhle lokutya.

I-Nickel plating inobunzima obuphezulu, kulula ukuyipolisha, inokukhanya okuphezulu, kwaye inokunyusa i-aesthetics. Ukungalungi kwayo kukuba ine-porosity. Ukoyisa le ntsilelo, i-multi-layer metal coatings ingasetyenziswa, kunye ne-nickel njengomaleko ophakathi.

I-Nickel yingubo ye-cathodic yentsimbi kunye ne-anodic yokugqoka ubhedu.

Ngokuqhelekileyo isetyenziselwa ukukhusela iingubo zokuhombisa ukwenzela ukuthintela ukubola kunye nokwandisa isibheno sobuhle. Ukufakwa kwe-nickel kwiimveliso zobhedu kulungele ukuthintela ukubola, kodwa ngenxa yexabiso eliphezulu le-nickel, i-alloys ye-copper tin isetyenziswa rhoqo endaweni ye-nickel plating.