Uma uzwa 'i-powder metallurgy stainless steel', iphimbo elisheshayo lihlala limayelana nobunkimbinkimbi bomumo oseduze nenetha nokonga okuphathekayo. Lokho kuyiqiniso, kodwa kuyingxenye yendaba kuphela. Ingxoxo yangempela, leyo eyenzeka phakathi konjiniyela abake bazama ukuyicacisa noma ukuyishintsha, izungeza igebe phakathi kwesithembiso semininingwane neqiniso le-workshop. Akuyona inhlamvu yomlingo; iyimpahla enesethi eqondile yemithetho. Ngibone amadizayini amaningi kakhulu ayiphatha njengokungena esikhundleni se-316L esebenziwe, kuphela ukuhlangana nezinkinga nge-porosity, ukusebenziseka okungahambisani, noma izimanga zokwelashwa kokushisa. Ukuheha kunamandla—kudala izingxenye eziyinkimbinkimbi njengezingxenye zamavalvu noma izindlu zezinzwa ezinodoti omncane—kodwa ukubulawa kudinga ukuhlonishwa kwenqubo, kusukela kusitokisi sempushana kuya kowokugcina.
Isithembiso Esiyinhloko kanye Nombuzo Oqhubekayo we-Porosity
Inzuzo eyisisekelo inkululeko yejometri. Sikhuluma ngezingxenye ezingaba yiphupho elibi uma umshini usuka esitokisini sebha noma i-investment cast. Cabanga nge-impeller encane yepompo eneziteshi zangaphakathi, noma indlu yensimbi yezokwelapha ene-undercuts. I-powder metallurgy kwenza lezi zisebenze ngokwezomnotho ngamavolumu aphakathi nendawo ukuya phezulu. Amabanga ensimbi engagqwali, ngokuvamile angu-304L, 316L, kanye ne-17-4 PH eyanda ukuduma, inikeza ukumelana nokugqwala okudingekayo kulezi zinhlelo zokusebenza.
Kodwa nansi isithiyo sokuqala: ukuminyana. Ukufinyelela ukuminyana okugcwele kuyabiza futhi akuwona umgomo ngaso sonke isikhathi. Izingxenye eziningi zesakhiwo zifakwa ezingeni elihlangabezana ne-mechanical spec. Lokhu kushiya i-porosity esele, exhumene. Akukona ngempela isici; kuyisici. Kodwa-ke, le porosity iyimpande yezinkinga eziningi ezingezansi. Kuthinta ukumelana nokugqwala okusebenzayo—izimbotshana zingabamba uketshezi futhi ziqalise ukugqwala, yingakho ezingxenyeni ezibalulekile zokubamba uketshezi, imisebenzi yesibili efana nokufakwa kwe-resin noma ukucindezela kwe-isostatic okushisayo (HIP) kungaxoxiswana. Ngikhumbula iqoqo lama-flange angu-316L weklayenti le-instrumentation yamakhemikhali; baphumelela ukuhlolwa kwesifutho sikasawoti njenge-sintered, kodwa behluleka ensimini ngemva kwezinyanga eziyisithupha ngenxa yokuthi i-porosity yangaphakathi ikhohlakele phakathi. Kudingeke ukuthi sibuyisele kabusha isinyathelo se-vacuum impregnation yawo wonke ama-oda azayo.
Lokhu porosity kunomthelela ngqo machinability. Ithuluzi lakho lokusika akukhona nje ukugunda insimbi; ihlangabezana nesakhiwo esiqinile ngezikhathi ezithile futhi esingenalutho. Lokhu kuholela engxoxweni encane, ukusheshisa ukuguga kwamathuluzi (ikakhulukazi kuma-drill nokompompi), kanye nendawo engaphezulu engabukeka inamachashaza uma ingaphathwanga kahle. Awukwazi ukusebenzisa okuphakelayo okufanayo kanye nesivinini njengezinto ezisetshenzisiwe. Kudinga ukusethwa okuqinile, amathuluzi abukhali, futhi kwesinye isikhathi ngisho neqhinga elihlukile lokusika uketshezi ukuvimbela ukuvala izimbotshana nge-swarf.
Ukwenza I-Sintered State: Ubambiswano Nezitolo Njenge-QSY
Yilapho ithiyori ihlangana khona nokusebenza, futhi kungani ukubambisana ne-Foundry kanye nesitolo semishini esiqonda lonke uchungechunge kubalulekile. Awukwazi nje ukuthumela i-sintered blank kunoma yisiphi isitolo se-CNC. Kumele bazi ukuthi baphetheni. Inkampani efana I-Qingdao Qiangsenyuan Technology Co., Ltd. (QSY) iveza indaba ethokozisayo. Ngaphezu kweminyaka engama-30 ekulingeni nasemishinini, babone ukuvela kwezinqubo ze-Near-net-shape. Ngenkathi umnyombo wabo ukugobolondo nokutshala imali, izimiso ziyahumusha. Baqonda ukuziphatha okubalulekile kwangemva kokubumba, ukucindezelwa komshini, nokubaluleka kokulawulwa kwenqubo yama-alloys. Okwe-a powder metallurgy insimbi engagqwali ingxenye, ubuchwepheshe babo bemishini ye-CNC buba ingxenye yesibili ebalulekile yezibalo.
Okubalulekile ukuxhumana. Uma sisebenze nezitolo ezingxenyeni ze-P/M, iphakheji yomdwebo kufanele icacise ububanzi bokuminyana obolile futhi uqaphele ukuthi iyinto ehlanganisiwe. Lokhu kuxwayisa umakhi wemishini. Izilinganiso ezibucayi zivame ukudinga iphasi yokuqeda ngemva kokucwilisa ukuze kulandiswe ngokuhlanekezela okuncane. Isitolo esinokuhlangenwe nakho kokusakazwa, njenge-QSY, sesivele sinolwazi kulokhu—ukuthola ama-datum, ukuqonda ukuthi ukusika kokuqala kungase kwembule imbobo, futhi kube nezinqubo zokubhekana nayo ngaphandle kokukhipha ingxenye. Okuhlangenwe nakho kwabo ngama-alloys akhethekile, njengezisekelo ze-nickel kanye ne-cobalt, kuphinde kuphakamise ukujwayelana nezinto ezilukhuni zomshini, okuyisisekelo esihle sokubhekana ne-sintered stainless.
Inselele eyodwa eqondile wukuxhuma. Ukuthepha ingxenye ye-sintered kucela inkinga uma imbobo ingalingani kahle futhi ukuthepha kungalungiswanga. Sivame ukucacisa ukugaywa kwentambo kokuxhumana okubalulekile, noma idizayini yokusetshenziswa kwezikulufu ezenza intambo ezihlanganisa okubalulekile kunokusikwa. Lolu uhlobo lwemininingwane egxivizwa emhlanganweni wangaphambi kokukhiqiza nozakwethu owenza imishini.
I-17-4 PH Conundrum: Imvula kanye Nokushintsha Kobukhulu
Uma amamaki ajwayelekile e-austenitic afana no-316L anezinselele zawo, 17-4 PH angenasici enziwe nge i-powder metallurgy iyisilwane saso. Isikhalazo sisobala: amandla aphezulu nobulukhuni ngemva kokwelashwa kokushisa. Kodwa inqubo yokwenza imvula ibe lukhuni ukuhamba ngezinyawo okunezintambo eziqinile.
Ukwelashwa okujwayelekile kwe-H900 (iminyaka engu-900°F) kuyasebenza, kodwa uguquko lwe-dimensional lubikezelwa kancane kunesitoko esisetshenzisiwe. Ingxenye isivele yancipha ngesikhathi i-sintering. Ukwelashwa kokuguga kwethula okunye, okuncane, kodwa okubalulekile ukushintsha kobukhulu. Ngokwengxenye enokubekezelelana okuqinile kuzo zonke izici eziningi, lokhu kungaba iphupho elibi. Sifunde lokhu kabuhlungu ekugijimeni kwe-prototype yengxenye ye-drone actuator. Ubukhulu be-as-sintered babuphelele. Ngemuva kokwelashwa kwesixazululo nokuguga, ububanzi be-bore buyehla ngaphezu komkhawulo wokubekezelela, kuyilapho ububanzi be-flange obungaphandle buthinteka kancane. I-anisotropy yayingenxa yesiqondiso sokuqala sokuhlangana kwempushana.
Isixazululo, nakuba sibiza kakhulu, ngokuvamile siwukuba umshini siye kubukhulu bokugcina esimweni sokuguga ngokweqile (Isimo A) noma isimo esinesixazululo, bese kuba budala. Kodwa lokhu kudinga ukwazi kahle ukuthi ingxenye ezokhula noma inciphe kangakanani phakathi nokuguga kulelo qoqo lezinto ezibonakalayo nesithando somlilo. Iba inqubo esekwe kwiresiphi, hhayi umsebenzi ojwayelekile. Leli zinga lokulawula kulapho ukusebenzisana phakathi komenzi wengxenye ye-P/M kanye nomakhi wemishini enembile kubaluleke kakhulu. Umakhi wemishini udinga idatha enembile yokwelashwa kokushisa evela ku-sinterer ukuze azi ukuthi yiziphi izinto okufanele zisetshenziswe kuhlelo lwayo lwe-CNC lomsebenzi womshini wangaphambi kweminyaka yobudala.
Lapho Kukhanya (Futhi Kufanele Ubheke Nini Kwenye Indawo)
Ngakho nini powder metallurgy insimbi engagqwali umpetha ongaphikiswa? Owezingxenye eziyinkimbinkimbi, ezincane ukuya kosayizi omaphakathi lapho ukusetshenziswa kwempahla evela esitokweni esigayiwe kuzoba ngaphansi kuka-40%, futhi lapho umthamo wokukhiqiza uvumela izindleko zamathuluzi zokufa. Izibonelo ezinhle kakhulu izingxenye zokukhiya, izingxenye zesistimu kaphethiloli wezimoto (njengamapuleti anyakazayo), neminye imihlathi yethuluzi lokuhlinza. Ukuvumelana kwempushana yesimanje nezithando zomlilo ezilawulwayo kunikeza ukuphindaphinda okuhle kakhulu kwe-batch-to-batch kulezi zinhlelo zokusebenza.
Kodwa-ke, ngokuvamile akuyona into engcono kakhulu yokukhetha izimo ezilula (i-spacer eyisisekelo noma iwasha), ezingxenyeni ezinkulu kakhulu lapho umthamo wokucindezela ukhawulelwe, noma izinhlelo zokusebenza ezidinga ukumelana nokugqwala okuphelele noma amandla okukhathala esakhiwo esincane esisebenza ngokugcwele, esifojiwe, nesixhunywe ngokugcwele. Kulezo zimo, umzila wokusakaza wendabuko osuka kuchwepheshe ofana ne-QSY, noma ukukhanda kusuka kubha, ungase uthembeke kakhulu futhi ungabizi. Ukwenza utshalomali, ngokwesibonelo, kungafeza inkimbinkimbi efanayo futhi ngokuvamile kuvame ukuqeda indawo engcono kanye nokuminyana kwamanye amajiyometri, nakuba ngesakhiwo sezindleko esihlukile.
I-matrix yesinqumo ayilokothi ibe mayelana nezindleko zezinto ezibonakalayo ngekhilogremu ngayinye. Imayelana nezindleko eziphelele ngengxenye ngayinye eqediwe, esebenzayo, ehlanganisa ukwenziwa kwemishini yesibili, noma yikuphi ukufakwa okudingekile noma ukucwenga, izilinganiso ze-scrap, nokusebenza kunkambu. Kuyinketho yobunjiniyela bezinhlelo.
Ikusasa Likuhlanganisela Nokubopha
Intuthuko ethokozisayo manje ayikho nje ekwakhiweni okusha kwempushana yensimbi engagqwali, kodwa ezinqubweni ezizibophayo. I-Metal Injection Molding (MIM), esebenzisa impushana ecolekile nesibophezelo sepulasitiki, iphusha imvilophu eyinkimbinkimbi kakhulu kune-P/M evamile yokucindezela kanye ne-sinter P/M, nakuba iza nezinselelo zayo zokubopha futhi ilungele izingxenye ezincane kakhulu.
Enye indawo yizinto ezixubile—impushana yensimbi engagqwali ehlanganiswe nezinto zokuthambisa ezifana nethusi noma into eqinisa ukuqina. Lokhu kungakha ama-bearings azigcobayo noma izingxenye ezinezakhiwo ezilinganiselwe emjikelezweni owodwa we-sintering. Kodwa futhi, lokhu kwethula okuguquguqukayo okusha kumishini. Usifaka kanjani umshini indawo eyinsimbi engu-90% nethusi engu-10%? Iphethini yokugqoka ithuluzi iyashintsha kuyo yonke ingxenye.
Ekugcineni, ukusebenza nge-powder metallurgy stainless steel kuwumsebenzi wokulawula ukuyekethisa kanye nolwazi olujulile lwenqubo. Kukuphoqa ukuthi ucabange ngokuphelele, kusukela kumklamo wokuqala wokufa kuya ekuhlolweni kokugcina kwe-QC. Akuyona into oyi-oda nje; kuyinqubo obamba iqhaza kuyo, usebenzisana eduze nomuntu oculayo kanye nochwepheshe bemishini ukuze uzulazule esikhaleni esiphakathi kokuqinile kwe-isotropic okuqinile kanye neqiniso elimangalisayo elikwaziyo, kodwa elixakile kancane, eline-sintered. Izinkampani eziphumelela ngayo yizo ezihlanganisa le mihlaba, njengokuthi umsebenzi odidiyelwe ohlanganisa ukusakaza kanye nemishini ye-CNC, efana ne-QSY, ilawula ama-nuances wokuziphatha kwe-alloy kusuka ekubunjweni kuya kumkhiqizo ophelile.
