Ukugaya ujantshi kuyinqubo yokususa izinto ngokuzungeza amasondo okugaya. I-mileage yokugaya yinde impela, ukusebenzisa uketshezi lokusika ngeke nje kwenyuse izindleko zokuyilungisa, kodwa futhi kubangele ukungcola okusabalele. Ngaphandle kokupholisa nokugcoba, ukushisa okukhiqizwa ohlelweni lokugaya akukwazi ukukhululwa ngesikhathi, ngakho-ke ukushiswa kwesitimela kuvame ukubonwa ngemva kwezinqubo zokugaya ujantshi ngenxa yezimo ezomile, isivinini esikhulu sokujikeleza kwamasondo okugaya (~ 3600 rpm) nomthwalo wokugaya (~ 2000 N) [1-4], njengoba kunikezwe ku-Fig.1. Ukuqhubeka nokuthuthukisa ukusebenza kahle kokugaya nokuthola ubuqotho obuhle bomhlaba, ukuklama nokukhiqiza izimbotshana emasondweni okugaya kuyindlela eyongayo nephumelelayo [5].
Fig.1.Ukushiswa okubangelwa ukugaya kanye nezingqimba ezimhlophe zokunamathisela ku-railhead.
Izazi zaseShayina zilungiselele amasondo okugaya anezimbotshana futhi zibonise ukusebenza kwazo kokugaya emshinini oziklanyelwe wona [5]. Kungaqashelwa ukuthi lapho ama-pores ekhiqizwa emasondweni okugaya, amandla aphezulu okucindezela ancipha ngo-35% ukusuka ku-83.74 MPa kuya ku-54.53 MPa. Imiphumela yokuhlolwa kokugaya iveze ukuthi ngokwanda kwe-porosity yamasondo okugaya, umthamo wokugaya ube ngcono kancane, izinga lokushisa lokugaya lehla futhi umthwalo wamasondo wehla. Imiphumela ikhomba ukuthi isondo lokugaya eline-porosity ephezulu linekhono elingcono lokuzigqoka, okuzuzisa ukuvimbela ukulayishwa kwamasondo.
Umdwebo 2.I-Surface morphology yamasondo okugaya ngaphambi nangemuva kokuhlolwa ane-porosity ehlukene: 8.12%(a) & (e), 15.81%(b) & (f), 18.60%(c) & (g) kanye no-21.18%(d) &(h).
Ungqimba oluqinile oluqinile nolufiphalayo lwe-etching olumhlophe lwabonwa kuwo wonke umzila wesitimela ophansi ngenxa yokushisa kokugaya, futhi i-WEL ewugqinsi yanikezwa ukuqina okuphansi kwamasondo okugaya, njengoba kunikezwe ku-Fig.3 naku-Fig.4. I-Bellow the WEL ungqimba lwe-pearlite olukhubazekile olwakhiwe ukuwohloka ngaphansi kwengcindezi ye-shear yamagrits abrasive. Ukuqina kwe-WEL kungu-5.77 GPa, cishe izikhathi ezi-2 ~ 3 ezinzima kune-matrix ye-pearlite. Izazi eziningi ziye zaphetha ngokuthi i-WEL inobudlelwane obuseduze nokuphuka kwesitimela [6-8]. Okubangelwa ukuqina okuxubile nokushear kwamasondo ngesikhathi sokusebenza kojantshi, imifantu ingase ivele phezulu. I-crack ekhiqiziwe izosakazeka ngokushesha kungqimba lwe-WEL ngenxa yemvelo yayo ephukayo, inwebe ku-WEL kanye nesixhumi esibonakalayo se-perlite noma ize isakazeke phansi ku-matrix ye-pearlite yakhe amaphutha abukhali kaloliwe[9]. Ngakho-ke, ukuqina nokuphuka kwamasondo kungadala ukwehluleka ngaphambi kwesikhathi kukajantshi waphansi futhi kungalawulwa ngokuphumelelayo ukuqina kwamasondo okugaya.
Umdwebo 3.Ukuqina kwe-WEL kanye nesendlalelo esikhubazekile.
Umdwebo 4.I-OM yezingxenye eziphambanayo zenkundla yesitimela ngokuqina okuhlukile kwamasondo okugaya: 8.12%(a), 15.81%(b), 18.60%(c) kanye no-21.18%(d).
Umshini wokugaya wesondo lokugaya elinezakhiwo zembobo ungaboniswa kumfanekiso 5. Ngenxa ye-engeli ephezulu ye-rake ne-grit density ephezulu esebenzayo, ama-chips okugaya aqale ancibilike ngaphansi kwezinga lokushisa eliphezulu kangaka abese enamathela endaweni yesondo ewohloka ikhono lokugaya futhi andise ukushisa kokugaya. Esivumelwaneni, isondo lokugaya elinezimbotshana linegunya elingcono lokuzigqoka futhi linomthelela ekulimaleni okuncane endaweni yesitimela[8]. Ngakolunye uhlangothi, izakhiwo ze-pore zandisa isikhala phakathi kwama-grits abrasive anikeza isikhala esanele sokugcina ama-chips nokukhulula ukushisa. Ama-chips angagoqeka ku-pore futhi asuswe ukusebenzisana okulandelayo kwama-abrasives, futhi angadlulisela ingxenye yokushisa ukusuka endaweni yokuxhumana. Ngakolunye uhlangothi, ukucindezelwa nokuphakama kwe-protrusion yegridi ngayinye esebenzayo kukhulu kunesondo elivamile lokugaya, okwandisa ukujiya kwe-chip engasikiwe futhi kunciphise umphumela wokuhlikihla phakathi kwegrit ehubhukayo nendawo yesitimela ukuze kuncishiswe ukukhathala kwangaphambili okubangelwa ukugaya ujantshi njengoba kuxoxiwe. Ngakho-ke, kuye ngokusebenza okuvelele kokugaya kanye nomphumela wokulimala ophansi ngokulandelana kwawo endaweni yesitimela, isondo lokugaya elinesakhiwo se-pore linamandla amakhulu okusetshenziswa kubuchwepheshe bokugaya ujantshi ngaphansi kwesivinini salo esikhulu nesimo sokugaya esomile.
Umdwebo 5.Umshini wokugaya wesondo lokugaya elinezakhiwo ze-pore.
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