Ungayifaka kanjani i-tungsten carbide?

    Imikhiqizo ye-Tungsten Carbide isetshenziswa ezinhlelweni eziningi, okuhlanganisa amathuluzi okusika, ukubhola, ukubhoboza, nezinye izinhlelo zokusebenza eziningi. I-Cemented Carbide inikeza ukumelana nokugqoka okuphezulu futhi inweba impilo yala mathuluzi ahlukahlukene wokugqoka nokusika. Isizathu sokuthi ingxenye yayo eyinhloko i-tungsten, okuwumthombo ongavamile futhi ongavuseleleki, intengo ye-carbide enosimende iphakeme kakhulu. Ngaphezu kwalokho, i-carbide enosimende inobunzima obuphakeme kakhulu, futhi amandla ayo okugoba aphansi kakhulu kunawezinye izinsimbi, njengensimbi. Ngenxa yalezi zizathu ezimbili, i-carbide enosimende kufanele ixhunywe kwezinye izinsimbi ngezindlela ezihlukene, njengokuxhuma okunentambo, i-clamping, ne-welding. Lesi sihloko sikhuluma ngendlela yokugcoba i-tungsten carbide kwezinye izinsimbi.

1. Iyini i-tungsten carbide?

    I-Tungsten carbide (WC), ebizwa nangokuthi i-cemented carbide, iyinhlanganisela yezinto ekhiqizwa inqubo ebizwa ngokuthi i-powder metallurgy. Impushana ye-WC ixutshwa nensimbi yokuhlanganisa, ngokuvamile i-cobalt noma i-nickel, ihlanganiswe kumathuluzi asetshenziswa ngaphambili, bese ifakwa esithandweni. Igama elithi “usimende” lisho izinhlayiya ze-tungsten carbide ezithwetshulwa ku-metallic binder material futhi “zifakwe usimende” ndawonye, ​​okwenza isibopho se-metallurgical phakathi kwezinhlayiya ze-tungsten carbide kanye ne-binder (WC-Co), kwinqubo yokuhlanganisa. Imboni ye-carbide enosimende ivamise ukubiza le nto ngokuthi “i-carbide”, nakuba amagama e-tungsten carbide ne-cemented carbide asetshenziswa ngokushintshana.  I-Carbide ibonisa amandla acindezelayo aphezulu, imelana nokuchezuka, futhi igcina amanani ayo okuqina emazingeni okushisa aphezulu, okuyindawo engokoqobo ewusizo ikakhulukazi ezinhlelweni zokusika insimbi. 

2 . Amaphuzu amabili okuqinisekisa impumelelo ekubhukeni i-tungsten carbide

A. Ukulawula izingcindezi ezibangelwa ukunwetshwa okuhlukile

B. Amazinga okufinyezwa kwezinto zomzali kanye nokumanziswa kwe-carbide nge-alloy ye-braze

    Ngesikhathi sokushisisa nokupholisa, isisekelo sensimbi yomzali ngokuvamile sizokhula futhi sinciphe ngenani eliphakeme kune-carbide.  I-Tungsten carbide inezinga lokunweba elishisayo elicishe libe yi-1/3 kuya ku-1/2 lensimbi.  Lapho umhlangano we-brazed uphola, ukucindezeleka okusalayo kungase kwakheke ngaphakathi kwe-carbide.  Ukupholisa kancane kancane kwe-carbide kunconywa ukugwema ukucindezeleka nokuqhekeka okungenzeka. Ukucisha akunconywa ngoba kungabangela imifantu kuma-carbides ngenxa yokufinyela ngokushesha kwesisekelo sensimbi yomzali.

3. Indlela yokukhetha i-alloy braze

    I-Tungsten carbide inzima ukumanzisa. Amaalloyi ensimbi esiliva anezengezo ezincane ze-Nickel (Ni) ngokuvamile asetshenziselwa ukubraze ama-carbides abe yinsimbi. Yiqiniso, kokubili i-carbide nensimbi kufanele kuhlanzeke ukuze ingxube ye-braze encibilikisiwe ikwazi ukumanzisa izindawo zokukhwelana ngokuphelele. Ukugaya i-carbide surface ukudala indawo ehlanzekile yokubhoboza kuyadingeka. Ukugaya futhi kunenzuzo yokuthambisa i-topography ye-carbide, engasiza ngokumanzisa i-alloy ye-braze kanye nokunamathela. Izingxenye zensimbi, ngokufanayo, zizodinga ukuhlanzwa ukuze kukhishwe noma imaphi ama-grisi ayinsalela, uwoyela, ukungcola, noma okunye ukungcola okungaphezulu.  

    ·Amaalloyi ensimbi esiliva atholakala ngokwezentengiso anezengezo ezincane ze-nickel (Ni) kanye neManganese (Mn) azomanzisa kalula izindawo ze-carbide ezinosimende. Lawa ma-alloys e-braze ngokuvamile abonisa ukumanzisa okuhle kwama-tungsten carbides.  Kunconywa ukuthi ukhethe insimbi yokugcwalisa enezinga lokushisa eliphansi lokubrawuza ukuze unciphise izingcindezi ezisele ngaphakathi kwelunga.  

Okwe-appliama-cations afaka ukugaywa kwama-carbides amakhulu, i-sandwich braze alloy ivame ukusetshenziswa.  Uma ama-carbides amancane (1/2 inch2) engakwazi ukusetshenziswa, ingxubevange yesangweji inenzuzo ekuvimbeleni ukuqhekeka kanye ne-warpage ye-carbide. Lawa ma-trimetals ambozwe ngesigcwalisi se-braze esiboshelwe izinhlangothi zombili zomgogodla wethusi.  

    ·Nakuba izingxoxo eziningi bezimayelana ne-tungsten carbide (WC), besiyobe senza iphutha uma singakhulumi ngedayimane le-polycrystalline noma i-PCD. Izinga lokushisa elishisayo le-PCD ngokuvamile ligcinwa lingaphansi kuka-1382°F (750 °C) ukuze kugwenywe ukucekelwa phansi kwedayimane.  Ngokuvamile, abakhiqizi bamathiphu e-PCD emizimbeni yensimbi bazosebenzisa insimbi yokugcwalisa i-braze esezingeni eliphansi, ephezulu yesiliva, njenge-BAg-24 braze alloy.  Abanye abakhiqizi basebenzisa ingxubevange ye-braze ngaphandle kwe-nickel noma i-manganese, njenge-BAg-5 noma i-BAg-7 braze alloy, enamazinga okushisa aphansi ancibilikayo kanye nezindawo zokumanzisa kancane ze-carbide nensimbi.

    I-brazing flux isetshenziselwa ukuvimbela i-oxidation yezindawo ezizohlanganiswa ngesikhathi sokushisisa komhlangano.  I-Flux powder isetshenziswa nama-alloys esiliva ajwayelekile.  Impushana ye-flux emnyama ivame ukutuswa abakhiqizi be-braze kanye ne-flux njengoba inokwengezwa kwe-boron futhi isebenza kangcono emazingeni okushisa aphezulu.

    Kunama-alloys amaningi okubhula asetshenziselwa i-carbide. Okwakudala kuyi-BAG-3, 50% yesiliva ene-Cadmium.  Lona umkhiqizo omuhle kakhulu, kodwa unayo i-Cadmium. Okuvame ukusetshenziswa yi-BAG-7, 56% yesiliva eneTin, ngoba imanzisa kalula; kodwa-ke, i-alloy brazing ebuthakathaka kakhulu, futhi ukwehluleka okuhlangene kuvamile nale alloy. Ingxubevange engeyona i-Cadmium enamandla i-BAG-22, 49% yesiliva ene-manganese, kodwa iyi-gummy kancane ekugelezeni. I-BAG-24, 50% Yesiliva, ayinayo i-cadmium futhi ihambisana.  Igeleza kahle kodwa icishe ibe buthakathaka ngo-40% kune-BAG-3 ne-BAG-22.

    Sincamela kakhulu i-Black Flux, nakuba abaningi begqama ngempumelelo nge-White Flux. Kuzo zombili izimo, kucacile ukuthi izinga lokushisa eliphakeme lishintshashintsha. Ngaphezu kwalokho, sithola ukuthi i-Black Flux ehlanzekile inikeza ukugeleza okungcono namalunga aqinile kune-Black Flux evamile.  

    Indawo yokugcina lapho amaphutha evame khona isekuklanyweni okuhlangene. Abashiseli abaqeqeshiwe ngokuvamile bafuna ukuhlanganisa izingxenye bese besebenzisa ubuhlalu. Lapho zishaya, zifuna ukuhlanganisa izingxenye bese zifaka i-alloy brazing ekuhlanganyeleni.   

    Lapho ubhula i-carbide, kuvame ukusebenza kahle kakhulu ukunyakazisa izinhlangothi nangaphansi kwenotshi, bese ubeka izingcezu zocingo oluxutshiwe lwe-alloy ngaphansi kwe-carbide.  Konke okwenzayo ngaleso sikhathi ukushisa kuze kube yilapho i-carbide ihlezi endaweni.   

    Izinga kufanele kube ukuthi i-carbide iqhuma noma insimbi iklebhula ngaphambi kokuba ukujoyina kuhluleke.