Sodium Cyanide Electroplating Zinc Process: A Comprehensive Analysis

ziviso

Electroplating inzira inoshandiswa zvakanyanya mumaindasitiri akasiyana siyana kusimudzira zvimiro zvesimbi. Pakati penzira dzakasiyana dze electroplating, Sodium Cyanide electroplating zinc inobata chinzvimbo chakakosha nekuda kwehunhu hwayo hwakasiyana uye zvakanakira. Ichi chinyorwa chine chinangwa chekupa ongororo yakadzama ye Sodium cyanide electroplating zinc nzira, inovhara misimboti yayo, matanho ekugadzirisa, kuumbwa kwekugezera, uye kufunga nezvekushanda.

Nheyo dzeSodium Cyanide Electroplating Zinc

Mu sodium cyanide electroplating zinc process, iyo yakakosha musimboti yakavakirwa pa electrolysis. Iyo yekugezera ye electroplating ine zinc ions uye zvimwe zvikamu. Kana magetsi akaiswa, zinc ions mubhavhu inoderedzwa pa cathode (chinhu chinofanira kuiswa), uye maatomu ezinc anoiswa pamusoro pe cathode, achiita zinc coating. Kuvapo kwe Sodium cyanide mukugeza unoita basa rakakosha. Inoshanda sechinhu chinogadzirisa, ichigadzira zvigadziriso zvakagadzikana zvine zinc ions. Uku kuomarara kunobatsira kudzora deposition rate ye zinc uye inovandudza kunaka kweiyo yakaiswa zinc layer. Semuenzaniso, mhinduro inogona kungomiririrwa se: Zn(CN)₄²⁻ + 2e⁻ → Zn + 4CN⁻ pane cathode. Iwo akaomeswa zinc ions muchimiro cheZn(CN)₄²⁻ akanyanya kugadzikana mubhavhu, izvo zvinotungamira kune imwe yunifomu uye yakanaka-grained zinc deposition kana ichienzaniswa neasina kuomeswa masisitimu.

Matanho Matanho

1. Pretreatment ye Substrate

Pamberi pe electroplating, substrate (chinhu chesimbi chichaputirwa) chinoda kunyatsogadziriswa. Iyi nhanho yakakosha kuve nechokwadi chekunamatira kwakanaka kweiyo zinc coating.

• Kuderedza: Iyo substrate inotanga kuderedzwa kubvisa chero mafuta, girizi, kana organic zvinosvibisa pamusoro payo. Izvi zvinogona kuwanikwa kuburikidza nenzira dzakadai sealkaline degreasing, apo substrate inonyudzwa mumushonga wealkaline une surfactants. Iyo alkaline solution inopindirana negrisi, ichiisa emulsifying uye ichibvumira kuti ishambidzwe. Semuenzaniso, yakajairwa alkaline degreasing solution inogona kunge iine sodium hydroxide, sodium carbonate, uye surfactants se sodium dodecyl sulfate.

• Kunhonga: Mushure mekubvisa mafuta, pickling inoitwa kubvisa ngura, okisidhi, uye kumwe kusvibiswa kusingaite kubva pane substrate pamusoro. An acid solution, yakadai sehydrochloric acid kana sulfuric acid, inowanzoshandiswa pakunhonga. Asidhi inopindirana nemaokisi ari pamusoro, ichinyunguditsa. Semuenzaniso, kana iri ngura (iron oxide) pane substrate yesimbi, maitiro nehydrochloric acid ndeiyi: Fe₂O₃ + 6HCl → 2FeCl₃ + 3H₂O. Mushure mekutora, substrate inoshambidzwa zvakakwana nemvura kuti ibvise chero asidi yakasara.

2. Kugadzirira kweElectroplating Bath

Kugadzirira kwekugeza kwe electroplating inhanho yakakosha mune sodium cyanide electroplating zinc process.

• Ingredients: Zvikamu zvikuru zvekugezesa zvinosanganisira zinc oxide (ZnO) sechitubu che zinc ions, sodium cyanide (NaCN) seyakaomesesa agent, uye sodium hydroxide (NaOH) seinoitisa munyu. Mukuwedzera, zvimwe zvinowedzera zvinogona kubatanidzwa kuvandudza kunaka kwekuputira, zvakadai sekupenya. Kune yakajairika yakaderera - cyanide electroplating bath, kuumbwa kungave: ZnO 8 - 12 g/L, NaCN 10 - 20 g/L, NaOH 80 - 120 g/L.

• Kusanganisa Maitiro: Kutanga, chikamu chemvura (chinenge chikamu chimwe - chetatu chehuwandu hwekugezesa huwandu) chinowedzerwa kune tangi yekuputira. Zvadaro, huwandu hunodiwa hwe sodium cyanide uye sodium hydroxide inowedzerwa uye inomutswa kusvikira yapera zvachose. Zvadaro, zinc oxide inowedzerwa zvishoma nezvishoma kune mhinduro ichienderera mberi ichikurudzira. Zinc oxide inopindirana nesodium hydroxide uye sodium cyanide kuti igadzire zvinodikanwa. Mushure mekuwedzera kwe zinc oxide, bhati inoderedzwa kusvika kuhuwandu hunodiwa nemvura. Pakupedzisira, izvo zvinowedzera zvinowedzerwa maererano nemirairo yemugadziri.

3. Electroplating Process

• Kugadzira iyo Electroplating Cell: Sero ye electroplating inosanganisira yekugezera yekugezera, iyo cathode (iyo substrate ichaputirwa), uye anode. Iyo anode inowanzogadzirwa nesimbi ye zinc. Kana magetsi achipfuura nemubhati, zinc ions inonyungudutswa kubva kune anode kupinda mubhavhu uye panguva imwe chete inoiswa pane cathode. Ikozvino density, iyo chiyero chezvino pane imwe unit nzvimbo ye cathode, inonyatsodzorwa. Kune sodium cyanide electroplating zinc, yakajairika density iripo kubva pa1 - 5 A/dm². Kudzikira kwazvino kungakonzeresa kudzikira kwemwero asi kunogona kutungamira kune imwe yunifomu uye yakakwenenzverwa-yakaomeswa coating. Nekune rimwe divi, yakakwira density yazvino inogona kuwedzera deposition rate asi inogona kukonzera matambudziko senge kusaenzana plating uye kupisa kwekuputira munzvimbo dzakakwirira - dzazvino.

• Tembiricha uye Agitation: Tembiricha yekugezera ye electroplating inokanganisawo maitiro ekuisa. Kazhinji, tembiricha yekugezera inochengetedzwa mumhando ye20 - 40 °C. Tembiricha yepamusoro inogona kuwedzera chiyero chekuisa asi inogona zvakare kuderedza cathode polarization, zvichitungamira kune yakaomesesa - yakaomeswa coating. Kuvhiringidza kwekugezera kwakakosha kuti uve nechokwadi chekugovera yunifomu yeoni kutenderedza cathode. Izvi zvinogona kuwanikwa kuburikidza nemagetsi kubvongodza, sekushandisa chibatiso, kana nekutubuka kwemhepo. Kushungurudzika kunobatsira kuzadza iyo zinc ions padhuze necathode pamusoro, kudzivirira kuumbwa kweiyo concentration gradients iyo inogona kutungamira mukusaenzana plating.

4. Post - kurapwa

• Rinsing: Mushure me electroplating, chinhu chakapfava chinosukwa zvakanaka nemvura kuti chibvise chero yasara plating mhinduro pamusoro payo. Matanho akawanda ekusukurudza anogona kuitwa, nekugeza kwekutanga kuri mumvura inotonhora kubvisa huwandu hwemushonga, uchiteverwa nekuwedzera rinses mumvura yakachena kuti uve nechokwadi chekubvisa zvachose chese chinosvibisa.

• Chromating: Chromating inowanzoitwa kuti iwedzere kusimudzira kushorwa kweiyo zinc - plated layer. Chinhu chakaputirwa chinonyudzwa mumushonga wechromating, une chromic acid kana munyu wayo. Iyo chromating process inoumba yakatetepa, inodzivirira chromate shanduko layer pamusoro peiyo zinc coating. Iyi layer inopa imwe dziviriro kubva mukuora nekuita sechivhariso uyezve nekuzviporesa kusvika pamwero wakati kana pamusoro pacho pakakwenywa. Kune marudzi akasiyana echromating, akadai seyero chromating, bhuruu - chena chromating, uye dema chromating, imwe neimwe ichipa akasiyana mazinga ekuora uye kutaridzika kwekunaka.

• Drying: Pakupedzisira, chinhu chakapfava uye chine chromated chinoomeswa. Kune zvikamu zviduku, zvinogona kuomeswa mu centrifugal dryer nemhepo inopisa, asi zvikamu zvakakura zvingave mhepo - yakaomeswa pakupisa kwekamuri. Kuomesa kwakakosha kudzivirira kuumbwa kwemavara emvura uye kuve nechokwadi chekugadzikana kwenguva refu kwekuputira.

Bath Maumbirwo Nepesvedzero Yayo

1. Zinc Oxide (ZnO)

Zinc oxide ndiyo inobva zinc ions mubhati re electroplating. Kuwanda kwe zinc oxide mubhavhu kunokanganisa chiyero chekuisa zinc. Kuwanda kwe zinc oxide kunowanzo tungamira kune yakakwira deposition rate. Nekudaro, kana iyo zinc ion concentration yakakwira zvakanyanya, inogona kukonzera matambudziko senge simba rekukanda rakashata (kugona kwemugadziriso weplating kuisa jasi reyunifomu pazvinhu zvakaoma-zvakaumbwa) uye coarser - coarsed coating. Mumabhavhu e-cyanide akaderera, iyo zinc oxide concentration yakafanira inowanikwa muchikamu chambotaurwa (8 - 12 g/L), iyo inopa chiyero pakati pedeposition rate uye kunaka kwekuputira.

2. Sodium Cyanide (NaCN)

Sodium cyanide inoshanda sechinhu chinonetsa mubhavhu. Inoumba macomplexes ane zinc ions, senge Zn(CN)₄²⁻. Iko kusanganiswa kwe sodium cyanide kunokanganisa kugadzikana kweaya macomplexes uye, nekudaro, deposition maitiro e zinc. Mumabhati e-cyanide akakwirira, huwandu hwakanyanya hwesodium cyanide inoshandiswa, iyo inopa simba rekukanda rakanakisa uye yakanyatso kurongeka. Nekudaro, mabhati e-cyanide akakwira anokonzeresa njodzi dzenharaunda nekuchengetedza njodzi nekuda kwehupfu hwecyanide. Kusiyana neizvi, mabhati akaderera - cyanide, ayo anonyanya kushandiswa mazuva ano, anoshandisa yakaderera yesodium cyanide (semuenzaniso, 10 - 20 g / L). Aya mabhati achiri kupa simba rekukanda rakanaka uye kunaka kwekuputira uku achidzikisa nharaunda nekuchengetedza kunetseka kune imwe nhanho. Chiyero che sodium cyanide kune zinc oxide (NaCN / ZnO ratio) inoitawo basa rakakosha. Chiyero chakakodzera chinovimbisa kuumbwa kweakagadzikana macomplexes uye akanyanya plating mamiriro. Semuenzaniso, mune mamwe maapplication, chiyero cheNaCN/ZnO chepakati pe1.5 - 2.5 chinodiwa.

3. Sodium Hydrooxide (NaOH)

Sodium hydroxide inoshanda semunyu unofambisa mubhavhu, ichiwedzera kugadzirwa kwemagetsi kwemhinduro. Izvi zvinobvumira kufambisa kunobudirira kwezvino panguva ye electroplating. Inobatsirawo kuchengetedza pH yekugezera. Iyo pH ye sodium cyanide electroplating zinc bath inowanzo mu alkaline range, yakapoteredza pH 12 - 14. pH yakagadzikana inokosha pakugadzikana kwema complexes uye nzira yose yekuisa. Kana iyo pH yakadzikira zvakanyanya, iwo macomplexes anogona kuora, zvichitungamira kune yakashata plating mhedzisiro. Kune rumwe rutivi, kana pH yakanyanyisa, inogona kukonzera matambudziko akadai sekunyanya kuora kweanode uye kuumbwa kwe zinc hydroxide precipitates mukugeza.

4. Wedzerai

• Brighteners: Mavhenekera anowedzerwa kubhati kuti avandudze kupenya uye kupenya kwechiputi chezinc. Vanoshanda nekugadzirisa morphology yepamusoro yezinc layer yakaiswa paatomu. Organic makomisheni akadai saccharin, coumarin, uye mamwe quaternary ammonium munyu anowanzoshandiswa seanopenya. Semuenzaniso, saccharin inogona kushambadza pamusoro peiyo cathode panguva ye electroplating, ichidzivirira kukura kwezinc crystals mune dzimwe nzira uye kukurudzira kuumbwa kwenzvimbo yakatsetseka uye yakajeka.

• Levelers: Malevelers anobatsira kukwenenzvera chero zvisizvo pane substrate pamusoro panguva ye electroplating. Ivo vanosarudzika dhipoziti kune yakakwirira - yazvino - density nzvimbo dze substrate, kuderedza ukobvu mutsauko pakati pepamusoro - uye yakaderera - yazvino - density matunhu uye zvichikonzera kuwedzera yunifomu coating. Mamwe mapolymers uye ma surfactants anogona kushanda sealevha mubhavhu re electroplating.

• Antioxidants uye Stabilizers: Izvi zvinowedzera zvinoshandiswa kudzivirira oxidation yezvikamu mubhati, kunyanya ion cyanide. Cyanide inogona kuve oxidized muhupo hwemhepo uye kumwe kusvibiswa, izvo zvinogona kutungamirira kuderera kwekubudirira kweiyo yakaoma agent uye kuchinja mumakemikari ekugezera. MaAntioxidants akadai sesodium sulfite anogona kuwedzerwa mubhavhu kuti asvitse okisijeni uye kudzivirira oxidation yecyanide. Stabilizers inowedzerwawo kuchengetedza kugadzikana kwekugezesa nekufamba kwenguva, kuve nechokwadi chekuenderana plating mhedzisiro.

Kushanda Kufunga

1. Kuchengetedza

Sezvo sodium cyanide ine muchetura zvakanyanya, kuchengetedzwa kwakasimba kunofanirwa kutorwa panguva yekubata uye kushanda kweiyo electroplating process. Vese vashandi vane chekuita nechiitiko ichi vanofanirwa kupfeka midziyo yekudzivirira yakafanira, kusanganisira magurovhosi, magirovhosi, uye zvekufemerera. Nzvimbo ye electroplating inofanira kunge yakanyatsopinda mhepo kudzivirira kuunganidzwa kwehutsi hunokachidza. Kana pane kurasika chero kupi zvako kana tsaona dzinosanganisira sodium cyanide, nzira dzekupindura dzechimbichimbi dzinofanirwa kuteverwa. Izvi zvinogona kusanganisira kusaita cyanide nemakemikari akakodzera (senge hypochlorite solutions) uye kuzivisa zviremera zvekuchengetedza zvakakodzera.

2. Bath Maintenance

• Nguva Dzose Kuongorora: Kuumbwa kweiyo electroplating bath kunofanirwa kugara ichiongororwa kuti ive nechokwadi chekuti kusungirirwa kwe zinc oxide, sodium cyanide, sodium hydroxide, uye zvinowedzera zviri mukati meiyo optimal range. Nzira dzekuongorora dzakadai setitration dzinogona kushandiswa kuona huwandu hwezvikamu izvi. Semuenzaniso, huwandu hwezinc ion hunogona kutsanangurwa nekuita titrating sampuli yebhati ine yakajairwa EDTA (ethylenediaminetetraacetic acid) mhinduro.

• Contamination Control: Kusvibiswa kwebhati kunogona kuitika kubva kwakasiyana-siyana, sekusvibiswa mune zvigadzirwa, 带入 yezvinhu zvekune dzimwe nyika kubva kune substrate panguva yekuputira, uye kuvaka - kumusoro kwekuita ne-zvigadzirwa. Kuti udzore kusvibiswa, filtration yakakodzera yebhati inofanira kuitwa. Iyo filtration system ine yakakodzera sefa midhiya inogona kubvisa zvimedu zvakasimba uye zvimwe zvinosvibisa organic. Mukuwedzera, kucheneswa nguva nenguva kwekugeza kunogona kudiwa. Semuenzaniso, kana tsvina yesimbi inorema (yakadai semhangura kana mutobvu) ikaungana mubhavhu, inogona kubviswa nekuwedzera makemikari anoumba precipitates netsvina iyi, achiteverwa nekusefa.

• Kuzadzazve kweZvikamu: Sezvo nzira ye electroplating ichienderera mberi, zvikamu mubhati zvinopedzwa. Zinc inoiswa pane cathode, uye mamwe emagetsi ekuwedzera uye ekuwedzera anogona kuora kana kupedzwa mukuita kwedivi. Naizvozvo, kugaro kuzadzazve zinc oxide, sodium cyanide, sodium hydroxide, uye zvinowedzera zvinodiwa kuchengetedza kuumbwa kwekugezera. Chiyero chekuzadzazve chinogona kutariswa zvichienderana nenguva yekuputira, huwandu hwezvikamu zviri kuputirwa, uye mhedzisiro yekuongorora yekugezesa.

3. Kugadzirisa matambudziko

• Murombo Coating Adhesion: Kana iyo zinc coating ine urombo hwekunamatira kune substrate, zvikonzero zvinogoneka zvinosanganisira kusakwana pretreatment ye substrate, isina kurongeka yekugezesa kuumbwa (yakadai senge isina kururama pH kana yakaderera complexing agent concentration), kana mazinga akanyanya ekusvibiswa mubhati. Kuti ugadzirise dambudziko iri, nzira yekugadzirira inofanira kuongororwa uye kugadziriswa. Kuumbwa kwebhati kunofanira kuongororwa uye kugadziriswa kana zvichidiwa, uye matanho anofanira kutorwa kuderedza kusvibiswa.

• Uneven Plating: Kusaenzana plating kunogona kukonzerwa nezvinhu zvakadai sezvisina kufanira kugovera ikozvino musero re electroplating, kwete-uniform agitation yebhati, kana kusiyana kwe geometry ye substrate. Kuti ugadzirise dambudziko iri, iyo electroplating cell setup inogona kugadziridzwa kuti ive nechokwadi chekugovera yunifomu ikozvino. Iyo nzira yekushungurudza inogona kugadziridzwa, uye zvigadziriso zvinogona kugadzirwa kuti zvibate substrate nenzira inosimudzira yunifomu kuputira. Kune akaomesesa-akaumbwa ma substrates, akakosha plating matekiniki kana kushandiswa kweanobatsira anode anogona kudiwa.

• Yakasvibira kana Yakasviba Coating: Iyo yakasviba kana yakasviba zinc coating inogona kunge yakakonzerwa nekusakwana kupenya kwekuvhenekesa mubhavhu, huwandu hwakanyanya hwetsvina, kana zvisizvo plating paramita (senge yakawandisa density ikozvino kana tembiricha yekugeza). Iyo inopenya inopenya inofanira kuongororwa uye kugadziriswa kana zvichidikanwa. Iyo yekugezera inofanirwa kucheneswa kuti ibvise kusvibiswa, uye maparamita eplating anofanirwa kugadziridzwa.

mhedziso

Iyo sodium cyanide electroplating zinc process inzira inoshandiswa zvakanyanya uye yakakosha yekupa kusaita ngura uye kupera kwekushongedza kune zvinhu zvesimbi. Kunzwisisa misimboti yayo, nhanho dzekugadzirisa, kuumbwa kwekugezera, uye kufunga kwekushanda kwakakosha kuti uwane yakakwira - yemhando yeplating mhinduro. Kunyange zvazvo iine mamwe matambudziko ezvakatipoteredza uye ekuchengetedza ane chokuita nekushandiswa kwesodium cyanide, ine matanho akakodzera ekuchengetedza uye kugadzirwa kwezvimwe zvinogadzirisa zvakatipoteredza (zvakadai seyakaderera - cyanide kana cyanide - maitiro emahara), inoramba ichiita basa rinokosha mumaindasitiri akasiyana-siyana, kusanganisira motokari, aerospace, uye zvemagetsi. Nekunyatso kudzora ese maficha ekuita, vagadziri vanogona kugadzira zinc - yakapfatwa zvigadzirwa zvine yakanakisa mhando uye kuita.