Foda Metallurgy Sintering Tsari

Sintering magani ne mai zafi da aka yi amfani da shi a kan ƙaramin foda don ba da ƙarfi da mutunci.Yanayin zafin jiki da ake amfani da shi don sintering yana ƙasa da wurin narkewa na babban abin da ke cikin kayan aikin Foda.

Bayan ƙaddamarwa, ƙwayoyin foda maƙwabta suna riƙe da juna ta hanyar welds masu sanyi, waɗanda ke ba da ƙarancin isasshen "ƙarfin kore" don a sarrafa su.A yanayin zafin jiki, hanyoyin watsawa suna haifar da wuyan wuyansa su yi girma a waɗannan wuraren tuntuɓar.

Akwai madogara guda biyu da suka wajaba kafin wannan tsarin “tsaftataccen yanayi” ya iya faruwa:
1.Cire man shafawa mai matsewa ta hanyar zubarwa da kona tururi
2.Reduction na surface oxides daga foda barbashi a cikin m.

Waɗannan matakan da tsarin sintering da kansu ana samun su gabaɗaya a cikin tanderu ɗaya, mai ci gaba ta hanyar zaɓi mai hukunci da sanyawa yanayin tanderun da kuma amfani da bayanin yanayin zafin da ya dace a cikin tanderun.

Sinter hardening

Ana samun murhun wuta waɗanda za su iya amfani da ingantattun matakan sanyaya a cikin yankin sanyaya kuma an ɓullo da maki na kayan da za su iya canzawa zuwa microstructures na martensitic a waɗannan ƙimar sanyaya.Wannan tsari, tare da maganin zafin jiki na gaba, an san shi da hardening sintering, tsarin da ya fito, a cikin 'yan shekarun nan, yana da babbar hanyar inganta ƙarfin da ba a so ba.

Rikicin lokaci mai wucewa

A cikin ƙaƙƙarfan da ke ƙunshe da ɓangarorin foda na baƙin ƙarfe kawai, ƙaƙƙarfan tsarin sintirin jihar zai haifar da raguwar ƙaƙƙarfan ƙaƙƙarfan ƙaƙƙarfan wuyan wuyan.Koyaya, al'ada ta gama gari tare da kayan PM na ƙarfe shine ƙara ƙarin foda mai kyau na jan ƙarfe don ƙirƙirar yanayin ruwa mai wucewa yayin sintering.

A yanayin zafi mai zafi, jan ƙarfe yana narkewa sannan ya bazu cikin ƙwayoyin foda na baƙin ƙarfe yana haifar da kumburi.Ta hanyar zaɓi mai kyau na abun ciki na jan karfe, yana yiwuwa a daidaita wannan kumburi a kan raguwa na halitta na kwarangwal foda na ƙarfe da kuma samar da wani abu wanda baya canzawa a cikin girma ko kadan a lokacin sintering.Ƙarin jan ƙarfe kuma yana ba da tasiri mai ƙarfi mai ƙarfi mai ƙarfi.

Dindindin ruwan lokaci sintering

Don wasu kayan, kamar siminti carbides ko hardmetals, ana amfani da tsarin sintiri wanda ya haɗa da samar da wani lokaci na ruwa na dindindin.Irin wannan nau'in nau'i na nau'i na nau'i na ruwa ya ƙunshi yin amfani da abin da ake ƙarawa zuwa foda, wanda zai narke kafin lokacin matrix kuma wanda sau da yawa zai haifar da abin da ake kira lokaci mai ɗaure.Tsarin yana da matakai uku:

Sake tsarawa
Yayin da ruwa ya narke, aikin capillary zai ja ruwan zuwa cikin pores kuma ya sa hatsi su sake tsarawa cikin tsari mai dacewa.

Magani-hazo
A wuraren da matsi na capillary yayi girma, atom za su fi dacewa su shiga cikin bayani sannan su yi hazo a cikin ƙananan yuwuwar sinadarai inda barbashi ba su kusa ko a tuntuɓar su.Wannan shi ake kira lallaɓawar lamba kuma yana ƙirƙira tsarin ta hanya mai kama da yaɗuwar iyakar hatsi a cikin ƙaƙƙarfan yanayi.Ripening Ostwald kuma zai faru inda ƙananan ɓangarorin za su shiga cikin mafita musamman kuma su yi hazo akan manyan ɓangarorin da ke haifar da ƙima.

densification na ƙarshe
Densification na m kwarangwal cibiyar sadarwa, ruwa motsi daga nagarta sosai cushe yankuna zuwa cikin pores.Domin madawwamin ruwa lokaci sintering ya zama m, babban lokaci ya kamata a kalla dan kadan mai narkewa a cikin ruwa lokaci da kuma "binder" ƙari ya kamata narke kafin wani babban sintering na m particulate cibiyar sadarwa faruwa, in ba haka ba sake shirya hatsi ba zai faru.

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Lokacin aikawa: Jul-09-2020