1. Isingeniso

Izintambo ze-Tungsten, ezinogqinsi olusuka emashumini ambalwa kuya emashumini ama-micro- metres, zakhiwe ngokwepulasitiki zaba ama-spirals futhi zisetshenziselwe uku- incan- descent nokukhipha imithombo yokukhanya. Ukwenziwa kwezintambo kusekelwe kubuchwepheshe bempushana, okungukuthi, impushana ye-tungsten etholakala ngenqubo yamakhemikhali ifakwa ngokulandelana kokucindezelwa, ukucwiliswa, kanye nokwakhiwa kwepulasitiki (i-rotary forging and drawing). Qaphela ukuthi inqubo yokuvala ucingo idinga ukuphumela ezintweni ezinhle zepulasitiki kanye nokunwebeka “okungaphakeme kakhulu”. Ngakolunye uhlangothi, ngenxa yezimo zokuxhashazwa kwama-spirals, futhi ngaphezu kwakho konke, ukumelana ne-high-creep edingekayo, izintambo ezenziwe kabusha azifanele ukukhiqizwa, ikakhulukazi uma zinesakhiwo esimahhadlahhadla.

Ukushintsha izici zemishini nepulasitiki zezinto ze-me-tallic, ikakhulukazi, ukunciphisa umsebenzi oqinile onzima ngaphandle kokwelashwa kokuthungatha kungenzeka usebenzisa ukuqeqeshwa kwe-me-chanical. Le nqubo ihlanganisa ukubeka insimbi ekuwohlokeni okuphindaphindiwe, okushintshanayo, nokuphansi kwepulasitiki. Imithelela ye-cyclic contraflexure ezicini eziwumshini zezinsimbi ibhalwe phansi, phakathi kokunye, ephepheni lika-Bochniak kanye ne-Mosor [1], lapha kusetshenziswa imicu yethusi enguthayela i-CuSn 6.5 %. Kwaboniswa ukuthi ukuqeqeshwa komshini kuholela ekuthambeni komsebenzi.
Ngeshwa, imingcele yemishini yezintambo ze-tungsten ezinqunywe ezivivinyweni ezilula ze-uniaxial tensile azanele ukubikezela ukuziphatha kwazo ohlelweni lokukhiqiza lwama-spirals. Lezi zintambo, naphezu kwezakhiwo ezifanayo zemishini, zivame ukubonakala ngendlela ehluke kakhulu ekungeneni kuyo. Ngakho-ke, lapho kuhlolwa izici zobuchwepheshe zocingo lwe-tungsten, imiphumela yokuhlolwa okulandelayo ibhekwa njengokwethenjelwa kakhudlwana: i-core wire winding, unidirectional torsion, ummese-edge compres-sion, bend-and-stretch, noma ibhande elihlehliswayo [2] . Muva nje, kuhlongozwe ukuhlolwa okusha kwezobuchwepheshe [3], lapho ucingo lubhekene nokuhlukunyezwa ngesikhathi esisodwa nge-tension (ukuhlolwa kwe-TT), futhi isimo sokucindezeleka-ngokombono wababhali-siseduze nalokho okwenzeka kwinqubo yokukhiqiza. kwe-fila-ments. Ngaphezu kwalokho, imiphumela yokuhlolwa kwe-TT okwenziwa ezintanjeni ze-tung-sten ezinobubanzi obuhlukene ibonise amandla ayo okulindela ukuziphatha kwabo kamuva phakathi nezinqubo zobuchwepheshe [4, 5].

Inhloso yomsebenzi owethulwe lapha ukuphendula umbuzo wokuthi, futhi uma, kungakanani izinga ukusetshenziswa kokwelashwa kokushintshashintsha kokuhamba ngebhayisikili (CDT) ocingweni lwe-tungsten ngokugoba okuqhubekayo kwamazwe ngamazwe ngendlela yokugunda [6], kungawulungisa yini umshini wayo nobuchwepheshe. izakhiwo ezibalulekile.

Ngokuvamile, ukuwohloka komjikelezo wezinsimbi (isb, ngokucindezela nokucindezelwa noma ukugoba kwamazwe amabili) kungase kuhambisane nezinqubo ezimbili ezihlukene zesakhiwo. Eyokuqala iyisici se-deformation ngama-amplitudes amancane kanye

kuhilela lokho okubizwa ngokuthi yizigigaba zokukhathala, okuholela ekutheni insimbi eqiniswe kakhulu iphenduke ibe yi-strain-thanjiswa ngaphambi kokubhujiswa kwayo [7].

Inqubo yesibili, ebusayo ngesikhathi sokuguqulwa ngama-amplitudes aphezulu, ikhiqiza i-heterogenization eqinile yamabhande e-shear akhiqiza ukugeleza kwepulasitiki. Ngenxa yalokho, kukhona ukuhlukana okukhulu kwesakhiwo sensimbi, ikakhulukazi, ukwakheka kwezinhlamvu ze-nano-size, ngaleyo ndlela, ukwanda okuphawulekayo kwezakhiwo zayo zemishini ngezindleko zokusebenza. Umphumela onjalo utholakala ngesib, ukubola okuphindaphindayo okuqhubekayo kanye nendlela yokuqondisa eyakhiwe ngu-Huang et al. [8], equkethe ukuphindaphindeka, ukushintshana, ukudlula (ukugingqika) kwemicu phakathi “kokuhlonyelwe” kanye namaroli abushelelezi, noma ngendlela eyinkimbinkimbi, okuyindlela yokugoba ngokuqhubekayo ngaphansi kwengcindezi [9], lapho umucu oweluliwe. iphambene ngenxa yokunyakaza okubuyisela emuva ngobude bayo besethi yamaroli ajikelezayo. Yiqiniso, ukuhlukaniswa okubanzi kwezinhlamvu kungabuye kutholakale ngesikhathi sokuguqulwa kwe-monotonic ngobunzima obukhulu, kusetshenziswa lokho okubizwa ngokuthi izindlela ze-Severe Plastic Deformation, ikakhulukazi, izindlela ze-Equal Channel Angular Extrusion [10] ezivame ukwanelisa izimo ezilula. ukugunda kwensimbi. Ngeshwa, asetshenziswa kakhulu esikalini saselabhorethri futhi ngokwezobuchwepheshe akunakwenzeka

ukuzisebenzisa ukuze uthole izici ezithile zemishini zamapheshana amade noma izintambo.

Eminye imizamo yenziwe futhi ukuze kuhlolwe umthelela wokugundwa okuguquguqukayo okusetshenziswe ngokuwohloka kwamayunithi amancane ekhonweni lokuvula izenzakalo zokukhathala. Imiphumela yocwaningo lokuhlola olwenziwe [11] emicu yethusi kanye ne-cobalt nge-contraflexure nge-shearing yaqinisekisa le thesis engenhla. Nakuba i-contraflexure enendlela yokugunda kulula ukuyisebenzisa ezingxenyeni zensimbi eziyisicaba, ukusetshenziswa okuqondile kwezintambo akuwenzi umqondo, ngoba, ngokwencazelo, akuqinisekisi ukuthola ukwakheka okufanayo, futhi ngaleyo ndlela izakhiwo ezifanayo i-circumference (enerediyasi eqondiswe ngokungafanele) yocingo. Ngalesi sizathu, leli phepha lisebenzisa indlela esanda kwakhiwa kanye neyokuqala ye-CDT edizayinelwe izintambo ezincane, ngokusekelwe ekugobeni okuqhubekayo okuhlangene nokugunda.

Umdwebo 1 Uhlelo lwenqubo yokuqeqeshwa kwemishini yezintambo:1 i-tungsten wire,2 ikhoyili ngocingo ukuze iqaqa,3 uhlelo lwesithupha olujikelezayo luyafa,4 ikhoyili ephendukayo,5 phula isisindo, futhi6 ibhuleki (isilinda sensimbi enebhande lethusi elizungezile)

2. Isivivinyo

I-CDT yocingo lwe-tungsten enobubanzi obungu-200 μm yenziwe kudivayisi yokuhlola eyakhelwe ngokukhethekile uhlelo lwalo oluboniswa kuFig. 1. Intambo engaboshiwe (1) evela kukhoyili

(2) enobubanzi obuyi-100 mm, yethulwa ohlelweni lwezinsimbi eziyisithupha (3), ezinezimbobo ezinobubanzi obufana nocingo, ezigxilwe endaweni evamile futhi zizungeza i-eksisi ngesivinini esingu-1,350 rev/ imiz. Ngemva kokudlula kudivayisi, intambo yaphinde yahanjiswa kukhoyili (4) enobubanzi obungu-100 mm izungeza ngesivinini esingu-115 rev/min. Amapharamitha asetshenzisiwe anquma isivinini somugqa wentambo ngokuhlobene namafa azungezayo ngu-26.8 mm/rev.

Idizayini efanele yesistimu ye-dies yayisho ukuthi yonke into yesibili yokufa yayizungeza ngendlela ehlukile (Fig. 2), futhi ucezu ngalunye locingo oludlula kumafa azungezayo lwalungaphansi kokugobeka okunezinhlangothi eziningi ngokugunda okungeniswa uku-ayina emaphethelweni angaphakathi kwendawo yokufa.

Umdwebo 2 Isakhiwo sohlelo lokufa okuzungezayo (okulebulwe ngenombolo3 ku-Fig. 1)

Umdwebo 3 Uhlelo lokufa: umbono ojwayelekile; b izingxenye eziyisisekelo:1 u-centric uyafa,2 i-eccentric iyafa,3 spacer izindandatho

Intambo engaxhunywanga yayingaphansi kwethonya lengcindezi yokuqala ngenxa yokusetshenziswa kwengcindezi, engagcini nje ngokuyivikela ekuboshweni, kodwa futhi inquma ukubamba iqhaza okuhlangene kokugoba nokugundwa kokugundwa. Lokhu kwakungenzeka ukufeza ukubonga ngebhuleki elifakwe kukhoyili ngendlela yomugqa wethusi wethini ocindezelwe isisindo (esiqokwe njengo-5 no-6 ku-Fig. 1). Umfanekiso wesi-3 ubonisa ukubukeka kokuqeqeshwa kwedivayisi lapho igoqiwe, kanye nengxenye yayo ngayinye. Ukuqeqeshwa kwezintambo kwenziwa ngezisindo ezimbili ezihlukene:

4.7 kanye no-8.5 N, kufika kwezine kudlula isethi yama-dies. Ingcindezi ye-axial ifinyelele ku-150 no-270 MPa ngokulandelanayo.

Ukuhlolwa kocingo okuqinile (kokubili esimweni sokuqala futhi esiqeqeshiwe) kwenziwa emshinini wokuhlola we-Zwick Roell. Ubude begeji yamasampula babungu-100 mm kanti izinga lokudonsa kanzima lalilikhulu

8×10⁻³ s⁻¹. Esimweni ngasinye, iphuzu elilodwa lokulinganisa (kulo ngalinye

kwezinhlobonhlobo) imele okungenani amasampuli amahlanu.

Ukuhlolwa kwe-TT kwenziwa emshinini okhethekile ohlelo lwawo olukhonjiswe ku-Fig. 4 ngaphambili owethulwe ngu-Bochniak et al. (2010). Isikhungo sentambo ye-tungsten (1) enobude obuyimitha elilodwa yafakwa endaweni yokubamba (2), bese kuthi iziphetho zayo, ngemva kokudlula emigqeni eqondisayo (3), nokunamathisela izisindo (4) ezingu-10 N ngayinye, bavinjwa ku-clamp (5). Ukunyakaza okuzungezayo kokubamba (2) kubangele ukusonteka kwezicucu ezimbili zocingo

(ziphindele phezu kwazo), ngeziphetho ezigxilile zesampula elihloliwe, lwenziwa ngokwanda kancane kancane kwezingcindezi eziqinile.

Umphumela wokuhlolwa kwaba inani lama-twist (N_T) okudingekayo ukuze kuqhume ucingo futhi ngokuvamile kwenzeka ngaphambili kwe-tangle eyakhiwe, njengoba kuboniswe ku-Fig. 5. Okungenani ukuhlolwa okuyishumi kokuhluka ngakunye kwenziwa. Ngemva kokuqeqeshwa, ucingo lwalunomumo omncane wamagagasi. Kufanele kugcizelelwe ukuthi ngokwamaphepha e-Bochniak and Pieła (2007) [4] kanye noFilipek (2010)

[5] ukuhlolwa kwe-TT kuyindlela elula, esheshayo, futhi eshibhile yokunquma izici zobuchwepheshe zezintambo ezihloselwe ukusongwa.

Umdwebo 4 Uhlelo lokuhlolwa kwe-TT:1 ucingo oluhloliwe,2 ukubamba okuzungeziswa yinjini kagesi, kuhlanganiswe nedivayisi yokurekhoda ye-twist,3 imiqulu yomhlahlandlela,4izisindo,5 imihlathi ebamba imikhawulo yocingo

3. Imiphumela

Umphumela wokungezwani kokuqala kanye nenani lokudlula kwinqubo ye-CDT ezimpahleni zezintambo ze-tungsten kuboniswa ku-Fig. I-6 kanye ne-7. I-scatter enkulu yemingcele etholwe yemishini yocingo ibonisa isilinganiso se-inhomogeneity yezinto ezitholwe ubuchwepheshe be-powder, ngakho-ke, ukuhlaziya okwenziwayo kugxile ekuthambekeni kwezinguquko zezakhiwo ezihloliwe hhayi kumanani azo aphelele.

Intambo ye-tungsten yezentengiso ibonakala ngamavelu amaphakathi e-yield stress (YS) alingana no-2,026 MPa, amandla okugcina eqinile (UTS) angu-2,294 MPa, ukunwetshwa okuphelele

A≈2.6% kanye ne-N_Tas much as 28. Kungakhathaliseki ukuthi

ubukhulu be-tension esetshenzisiwe, i-CDT iphumela kokuncane kuphela

ukwehla kwe-UTS (okungadluli ku-3 % ocingweni ngemva kokudlula okune), futhi kokubili i-YS kanyeA zihlale zisezingeni elifanayo (Amakhiwane 6a–c kanye no-7a–c).

Umfanekiso 5 Ukubuka kwentambo ye-tungsten ngemva kokuphuka ekuhlolweni kwe-TT

Umdwebo 6 Umthelela wokuqeqeshwa kwemishini (inani lamaphasi n) kumishini (a–c) kanye nezobuchwepheshe (d) (kuchazwe ngu-N_Tekuhlolweni kwe-TT) izakhiwo zocingo lwe-tungsten; isisindo esinamathiselwe se-4.7 N

I-CDT ihlale iholela ekwenyukeni okukhulu kwenani lama-wire twist N_T. Ikakhulukazi, emaphasini amabili okuqala, uN_Tifinyelela ngaphezu kwama-34 ekushubeni kwengcindezi okungu-4.7 N futhi icishe ibe ngu-33 ngokushuba okungu-8.5 N. Lokhu kumelela ukwanda okucishe kube ngama-20% maqondana nentambo yokuhweba. Ukusebenzisa inani eliphezulu lokuphasa kuholela ekwenyukeni okwengeziwe kwe-N_Tkuphela esimweni sokuqeqeshwa ngaphansi kwe-tension ye-4.7 N. Ucingo ngemva kokudlula okune lubonisa isilinganiso sobukhulu be-N_Tokungaphezu kwama-37, okuthi, uma kuqhathaniswa nocingo olusesimweni sokuqala, kufanekisela ukwanda okungaphezu kwama-30%. Ukuqeqeshwa okwengeziwe kocingo emazingeni aphezulu ngeke kusashintsha ubukhulu be-N ezuzwe ngaphambilini._Tamanani (Amakhiwane 6d no-7d).

4. Ukuhlaziya

Imiphumela etholiwe ikhombisa ukuthi indlela esetshenziselwa i-tungsten wire CDT empeleni ayishintshi imingcele yayo yemishini enqunywe ekuhlolweni okuqinile (kube nokuncipha kancane kwamandla okugcina okuqinile), kodwa yandise kakhulu

izakhiwo zobuchwepheshe zihlose ukukhiqizwa kwama-spirals; lokhu kuvezwa inani lama-twist ekuhlolweni kwe-TT. Lokhu kuqinisekisa imiphumela yocwaningo lwangaphambili luka-Bochniak no-Pieła (2007)

[4] mayelana nokuntuleka kokuhlangana kwemiphumela yokuhlolwa okuqinile nokuziphatha okuqashelwe kwezintambo ekukhiqizeni ama-spirals.

Ukusabela kwezintambo ze-tungsten ohlelweni lwe-CDT kuncike kakhulu ekucindezelekeni okusetshenzisiwe. Ngamandla we-tension ephansi, umuntu ubheka ukukhula okuphambene nenani lokusonteka nenani lokudlula, kuyilapho ukusetshenziswa kwamanani amakhulu okudonsa kuholela (sekuvele ngemva kokudlula okubili) ekufinyeleleni isimo sokugcwala kanye nokuzinza kobuchwepheshe obutholakale ngaphambilini. izakhiwo (Fig. 6d no-7d).

Ukusabela okuhlukahlukene okunjalo kwentambo ye-tungsten kugcizelela iqiniso lokuthi ubukhulu be-tension bunquma ushintsho lwenani kokubili isimo sokucindezeleka kanye nesimo sokukhubazeka kwento futhi ngenxa yalokho ukuziphatha kwayo okunwebekayo-kwepulasitiki. Ukusebenzisa ukushuba okuphezulu ngesikhathi senqubo yokugoba kwepulasitiki ocingweni oludlula phakathi kokungaqondani kahle okulandelanayo kuphumela endaweni encane yokugoba intambo; ngakho-ke, uhlobo lwepulasitiki oluya ku-axis yocingo olubhekele umshini wokugunda lukhulu futhi luholela ekugelezeni kwepulasitiki kwendawo kumabhande okugunda. Ngakolunye uhlangothi, ukungezwani okuphansi kubangela ukuthi inqubo ye-CDT yocingo yenzeke ngokubamba iqhaza okukhulu kwe-elastic strain (okungukuthi, ingxenye ye-plastic strain incane), okuvumela ukubusa kokuguqulwa kwe-homogeneous. Lezi zimo zihluke kakhulu kulezo ezenzeka ngesikhathi sokuhlolwa kwe-uniaxial tensile.

Kufanele futhi kuqashelwe ukuthi i-CDT ithuthukisa izici zobuchwepheshe kuphela ngezintambo ezinekhwalithi eyanele, okungukuthi, ezingenakho ukukhubazeka okubalulekile kwangaphakathi (izimbotshana, ama-voids, ama-discontinuities, ama-micro-cracks, ukuntuleka kokunamathela okwanele kokuqhubeka emingceleni yokusanhlamvu, njll. ) okubangelwa ukukhiqizwa kocingo nge-powder metallurgy. Uma kungenjalo, ukuhlakazeka okukhulayo kwenani elitholiwe lokusonta N_Tkanye nokwenyuka kwenani lamaphasi kubonisa ukujula kokwehlukaniswa kwesakhiwo socingo ezingxenyeni zalo ezihlukahlukene (ubude) ngaleyo ndlela kungase futhi kusebenze njengesici esiwusizo sokuhlola ikhwalithi yocingo lwezohwebo. Lezi zinkinga kuzoba yisihloko sophenyo oluzayo.

Umdwebo 7 Umthelela wokuqeqeshwa kwemishini (inani lamaphasi n) kumishini (a–c) kanye nezobuchwepheshe (d) (kuchazwe ngu-N_Tekuhlolweni kwe-TT) izakhiwo zocingo lwe-tungsten; isisindo esinamathiselwe se-8.5 N

5. Iziphetho

I-1, i-CDT yezintambo ze-tungsten ithuthukisa izakhiwo zabo zobuchwepheshe, njengoba kuchazwe ku-torsion nokuhlolwa kwe-tension ngu-N._Tngaphambi kokuphuka.

2, Ukwanda kwe-N_TInkomba cishe ngama-20 % ifinyelelwa ngocingo olungaphansi kochungechunge olubili lwe-CDT.

3, Ubukhulu be-wire tension ohlelweni lwe-CDT bunomthelela omkhulu ezimpahleni zayo zobuchwepheshe ezichazwe ngevelu ye-N._Tinkomba. Inani layo eliphakeme kakhulu lafinyelelwa ngocingo olungaphansi kokucindezeleka okuncane (i-tensile stress).

4, Ukusebenzisa kokubili ukungezwani okuphezulu kanye nemijikelezo eyengeziwe yokugoba kwamazwe ngamazwe ngokugunda akulungile ngoba kuphumela kuphela ekuzinziseni inani elifinyelelwe ngaphambili le-N._Tinkomba.

5, Ukuthuthukiswa okuphawulekayo kwezakhiwo zobuchwepheshe zocingo lwe-tungsten ye-CDT akuhambisani noshintsho lwemingcele yemishini enqunywe ekuhlolweni okuqinile, okuqinisekisa inkolelo ebambelele ekusetshenzisweni okuphansi kokuhlolwa okunjalo ukulindela ukuziphatha kobuchwepheshe kocingo.

Imiphumela yokuhlola etholiwe ibonisa ukufaneleka kwe-CDT yentambo ye-tungsten ekukhiqizeni okuvunguzayo. Ikakhulukazi, ngokusekelwe endleleni esetshenziswayo ukuze kuthuthukiswe ubude bezintambo ngokulandelanayo, ukugoba okujikelezayo, okunezinhlangothi eziningi okuhambisana nokudonsa kanzima, kubangela ukuxegiswa kokucindezeleka kwangaphakathi. Ngenxa yalesi sizathu, kunomkhawulo ekuthambekeni kokuphuka kocingo ngesikhathi kwakhiwa ama-spirals epulasitiki. Ngenxa yalokho, kwaqinisekiswa ukuthi ukunciphisa inani lemfucuza ngaphansi kwezimo zokukhiqiza kwandisa ukusebenza kahle kwenqubo yokukhiqiza ngokuqeda imishini yokukhiqiza ezenzakalelayo lapho, ngemva kokugqashula ucingo, isitobhi esiphuthumayo kufanele sivulwe “ngokwenziwa”. ngo-opharetha.