Sintered Powder

Powder sintering imaphatikizapo kukweza kutentha kwa chobiriwira chobiriwira, (gawo la ufa woponderezedwa), kufika pamlingo wina ndikuusunga pa kutentha kwa nthawi inayake.Kutentha kwa sintering nthawi zambiri kumakhala pakati pa 70% ndi 90% ya malo osungunuka a zitsulo za ufa.Izi zipangitsa kuti njira zolumikizirana zichitike pakati pa tinthu tating'ono ta ufa topanikizidwa pamodzi mu compact.Kumangirira mkati mwa chobiriwira chobiriwira ndikofooka ndipo gawo lopanikizidwa losapindika nthawi zambiri limakhala ndi umphumphu wokwanira wogwiridwa.Kulumikizana komwe kumachitika panthawi ya sintering kumalimbitsa gawolo.

Pa sintering, munthu tinthu nyumba kutha ndipo zinthu zimapanga ngati misa.Sintering wamba sikudzathetsa porosity yonse mu gawoli, komabe imachepetsanso porosity.Kuphatikiza pa kuchepetsedwa kwa voliyumu, sintering imathanso kulekanitsa madera a porosity yolumikizidwa pagulu lobiriwira.Madera akutaliwa amakhala otsekeka, chifukwa amachotsedwa ku chilengedwe.Sintering ndi chikhalidwe cha kuwotcha kwa zowonjezera mu ufa zomwe zinali zofunika pazigawo zoyamba zokonza.Kuchotsa zigawo zomwe sizikufunikanso monga mafuta, zomangira ndi zowonongeka, ndizofunikira kuti zikhale zoyera za zinthu zomaliza.Kuwonjezera pa kuonjezera mphamvu ndi kachulukidwe wa zinthu za gawo, sintering kumawonjezera ductility, matenthedwe madutsidwe ndi madutsidwe magetsi.Shrinkage idzachitika panthawi ya sintering, koma idzawerengedwera pamene zinthu zopanga zinthu zimayendetsedwa.

Njira zomwe zimayambitsa kulumikizana panthawi ya sintering ndizosiyanasiyana komanso zovuta.Njira yaikulu yomwe kugwirizanitsa kumachitika kumaonedwa kuti ndi kufalikira, njira zidzasiyana malinga ndi zinthu zopangira zinthu komanso makhalidwe a ufa.Njira zina zomwe zitha kuchitika limodzi ndi kufalikira ndi kutuluka kwa pulasitiki, recrystallization, kukula kwambewu, kayendedwe kazinthu zamadzimadzi komanso zoyendera zamtundu wa nthunzi.Makhalidwe akuthupi amitundu yosiyanasiyana yolumikizana angakhale osiyana.Kulumikizana kwa tinthu ndi njira ziwiri zosiyana kukuwonetsedwa pansipa.Kulumikizana kophatikizana kumachepetsa mtunda pakati pa tinthu tating'onoting'ono, kuchepetsa danga.The gawo zinthu zoyendera amawonjezera zakuthupi, pamene kusunga particles mtunda wofanana padera.

Kumangirira njira pa sintering ndizovuta komanso zosiyana, komabe mphamvu yaikulu yomwe imapangitsa kuti tinthu tigwirizane ndi tinthu tating'onoting'ono timayesedwa kuti ndi kuchepetsa mphamvu chifukwa cha kuchepa kwapakati.Ufa wokhala ndi malo ochulukirapo udzakhala ndi mphamvu yoyendetsa galimoto yopita ku mgwirizano ndi kuchepetsa mphamvu zomwe zingatheke.

Alloying osiyana zitsulo ufa amapezekanso pa sintering.Kutentha kwa sintering kuyenera kukhala kochepa kuposa kutentha kosungunuka kwa chimodzi mwa zigawo za ufa.Nthawi zina, kutentha kwa sintering kumakhala pamwamba pa malo osungunuka a zipangizo koma pansi pa malo osungunuka.Izi zimatchedwa liquid phase sintering.Sintering yamadzimadzi imatha kuthetsa porosity ndikupanga magawo okhala ndi zinthu zabwino kwambiri.