Umahluko phakathi kwe-galvanizing, i-cadmium plating, i-chrome plating, kunye ne-nickel plating

Gukuhlaziya

Iimpawu:

I-Zinc izinzile xa umoya womile kwaye ayitshintshi umbala lula. Kwiindawo ezimanzi nezinomswakama, isabela kwi-oxygen okanye i-carbon dioxide ukuze yenze iifilimu ze-oxide okanye ze-alkaline zinc carbonate, ezinokuthintela i-zinc ukuba iqhubeke i-oxidation kwaye inike ukhuseleko.

I-Zinc ichaphazeleka kakhulu kukugqwala kwii-asidi, ii-alkali, kunye nee-sulfides. Umaleko we-galvanized ngokubanzi kufuneka uphathwe ngokugqwala. Emva kokugqwala kwisisombululo se-chromic acid okanye i-chromate, ifilimu yokugqwala eyenziweyo ayivezwa lula emoyeni ofumileyo, nto leyo ephucula kakhulu amandla ayo okulwa nokugqwala. Kwiindawo zasentwasahlobo, iindawo ezibhityileyo (ubukhulu bodonga <0.5m), kunye neendawo zentsimbi ezifuna amandla aphezulu oomatshini, kufuneka kususwe i-hydrogen, ngelixa iindawo ze-copper kunye ne-copper alloy zisenokungafuni ukususwa kwe-hydrogen.

Ukugalela i-galvanizing kunexabiso eliphantsi, kulula ukukucubungula, kwaye kunemiphumo emihle. Amandla aqhelekileyo e-zinc aphantsi kakhulu, ngoko ke ukugalela i-zinc kugalelo olungena-anodic kwiintsimbi ezininzi.

I-Galvanization isetyenziswa kakhulu kwiimeko zomoya nakwezinye iindawo ezilungileyo. Kodwa ayifanelekanga ukusetyenziswa njengesixhobo sokungqubana.

Ci-hroom plating

Iimpawu: Kwiindawo ezidibana nomoya wolwandle okanye amanzi olwandle, nakumanzi ashushu angaphezu kwama-70℃, i-cadmium plating izinzile, inokumelana nokugqwala okunamandla, i-lubrication elungileyo, kwaye inyibilika kancinci kwi-hydrochloric acid enyibilikisiweyo, kodwa inyibilika kakhulu kwi-nitric acid kwaye ayinyibiliki kwi-alkali. I-oxide yayo nayo ayinyibiliki emanzini. I-cadmium coating ithambile kune-zinc coating, ine-hydrogen embrittle encinci kwaye inamathelana ngamandla.

Ngaphezu koko, phantsi kweemeko ezithile ze-electrolytic, i-cadmium coating efunyenweyo ithandeka ngakumbi kuno-zinc coating. Kodwa igesi eveliswa yi-cadmium ngexesha lokunyibilika inobungozi, kwaye iityuwa ze-cadmium ezinyibilikayo nazo zinobungozi. Phantsi kweemeko eziqhelekileyo, i-cadmium isebenza njenge-cathodic coating kwintsimbi kwaye njenge-anodic coating kwiindawo zolwandle nakwimozulu yobushushu obuphezulu.

Isetyenziswa kakhulu ukukhusela iindawo ekungcoleni okubangelwa ngamanzi olwandle okanye izisombululo zetyuwa ezifanayo, kunye nomphunga wamanzi olwandle ogcweleyo. Iindawo ezininzi kwimizi-mveliso yeenqwelo-moya, eyolwandle, neye-elektroniki, imithombo, kunye neendawo ezinemisonto zigqunywe nge-cadmium. Ingapholishwa, ixutywe nge-phosphate, kwaye isetyenziswe njengesiseko sepeyinti, kodwa ayinakusetyenziswa njengesixhobo.

Isigqubuthelo seChromium

iimpawu:

I-Chromium izinzile kakhulu kwiindawo ezifumileyo, kwi-alkaline, kwi-nitric acid, kwi-sulfide, kwi-carbonate solutions, nakwii-organic acids, kwaye inyibilika lula kwi-hydrochloric acid nakwi-hot concentrated sulfuric acid. Phantsi kwesenzo se-direct current, ukuba umaleko we-chromium usebenza njenge-anode, inyibilika lula kwi-caustic soda solution.

Umaleko we-chromium unamathele kakhulu, uqinile kakhulu, i-800-1000V, umelana kakuhle nokuguguleka, ukukhanya okukhanyayo okunamandla, kunye nokumelana nobushushu obuphezulu. Awutshintshi umbala ongaphantsi kwe-480℃, iqala ukunyibilikisa ioksijini engaphezulu kwama-500℃, kwaye kunciphisa kakhulu ubulukhuni kwi-700℃Ingxaki yayo kukuba i-chromium iqinile, iyaphuka, kwaye iyakwazi ukuqhekeka, ingakumbi xa iphantsi kwemithwalo yempembelelo etshintshanayo. Kwaye inemibhobho.

Isinyithi seChromium sithambekele ekungangeni emoyeni, nto leyo ebangela ukwenziwa kwefilimu yokungangeni emoyeni, nto leyo etshintsha amandla echromium. Ke ngoko, ichromium iba yi-cathodic coating kwisinyithi.

Akulunganga ukufaka i-chrome plating ngqo njengomaleko ochasene nokugqwala phezu komphezulu weendawo zentsimbi. Ngokubanzi, i-electroplating enezingqimba ezininzi (umz. i-copper plating→ipleyiti ye-nickel→i-chromium plating) iyafuneka ukuze kufezekiswe injongo yokugqwala

ukuthintela kunye nokuhombisa. Okwangoku isetyenziswa kakhulu ekuphuculeni ukumelana nokuguguleka kweendawo, ukulungisa ubungakanani, ukubonakaliswa kokukhanya, kunye nokukhanya okuhombisayo.

Isigqubuthelo seNickel

iimpawu:

I-Nickel izinzile kakuhle kwiikhemikhali emoyeni kwaye inesisombululo se-alkaline, ayitshintshi umbala lula, kwaye inyibilikiswa kuphela kumaqondo obushushu angaphezu kwama-600.° C. Inyibilika kancinci kwi-sulfuric acid nakwi-hydrochloric acid, kodwa inyibilika lula kwi-nitric acid enyibilikisiweyo. Inyibilika lula kwi-nitric acid exineneyo kwaye ngenxa yoko inokumelana okuhle nokugqwala.

I-nickel plating inobunzima obuphezulu, kulula ukuyipolisha, ibonakalisa ukukhanya okuphezulu, kwaye inokunyusa ubuhle. Ingxaki yayo kukuba ine-porosity. Ukuze koyiswe le ngxaki, kungasetyenziswa ii-multi-layer metal coatings, kunye ne-nickel njengomaleko ophakathi.

I-Nickel yingubo ye-cathodic yesinyithi kunye nengubo ye-anodic yethusi.

Isetyenziswa kakhulu ukukhusela iingubo zokuhombisa ukuze kuthintelwe ukugqwala nokwandisa ubuhle. I-nickel plating kwiimveliso zobhedu ifanelekile ekuthinteleni ukugqwala, kodwa ngenxa yexabiso eliphezulu le-nickel, i-copper tin alloys zihlala zisetyenziswa endaweni ye-nickel plating.