Resin-bonded sib tsoo log muaj cov nplej abrasive nyob rau hauv ib daim ntawv cog lus, uas tej zaum yuav los yog tsis muaj cov fillers. Hom log no feem ntau muaj qhov porosity qis dua sintered bonded cov cuab yeej.
Resins yog cov kua nplaum uas muaj peev xwm ua kom tawv. Lawv yog cov polymers, piv txwv li cov saw loj molecular uas muaj cov monomers. Monomers yog cov khoom uas muaj cov ntsiab lus C, H, O, N, Cl, S los yog F, los ntawm cov oligomers ("resins") yog synthesized. Cov oligomers no tom qab ntawd hloov mus rau hauv kev sib txuas, cov khoom tsis sib haum xeeb hauv cov kauj ruam thib ob, hu ua kev kho, uas yuav muaj cua sov, catalysts, fillers lossis siab.
Abrasive resin bonds muaj xws li ib qho resin los yog ib qho kev sib txuas ntawm cov resins, uas yuav muaj cov fillers. Cov resins lawv tus kheej feem ntau yog tsim los ntawm esterification los yog saponification ntawm cov organic tebchaw. Fillers tsis tsuas yog muaj lub luag haujlwm ntawm kev txhawb nqa daim ntawv cog lus ntawm toughness, tshav kub tsis kam, lub zog thiab kev ruaj ntseg tawg, tab sis kuj txhawb cov txheej txheem sib tsoo raws li cov khoom siv thib ob. Silicates, sulfides, halides nce lub zog thiab hnav tsis kam ntawm daim ntawv cog lus thiab tiv thaiv oxidative degradation ntawm cov resin. Hauv kev txiav cov log, cov ntaub ntawv cog lus kuj tseem ntxiv nrog cov ntaub ntawv loj xws li fiberglass thiab linen.
Raws li lub zog thiab kub tsis kam, resin bonds tuaj yeem muab faib ua peb pawg:
• Phenolic resins,
• Polyimide thiab polyamide resins
• Epoxy lossis polyurethane resins, feem ntau hu ua yas bonds.
1.1 Phenolic resins
Phenolic resin bonds, tshwj xeeb tshaj yog phenolic aldehyde resin bonds, yog cov feem ntau resin bonds; cov cuab yeej ntawm hom nyiaj no muaj kev lag luam loj tshaj plaws nyob rau hauv cov pa sib tsoo log, thib ob tsuas yog cov cuab yeej sintered. Keeb kwm, hom nyiaj no hu ua Bakelite, yog li tsab ntawv "B" tau khaws cia rau hauv ntau qhov sib tsoo log specifications. Piv nrog rau lwm cov resins, phenolic resins yog pheej yig dua thiab yooj yim rau cov duab.
Phenolic resins tau txais los ntawm cov tshuaj tiv thaiv ntawm phenol thiab aldehydes. Phenols yog cov tshuaj tsw qab nrog cov pab pawg hydroxyl sib txuas rau cov nplhaib uas muaj ntxhiab. Lub synthesis ntawm phenol feem ntau yog ua los ntawm cov txheej txheem propylene, uas yog txheej txheem ntawm oxidizing propylene (isopropylbenzene) thiab huab cua rau propylene peroxide, uas tom qab ntawd tawg rau phenol thiab acetone. Kev nyab xeeb yog qhov tseem ceeb hauv kev tsim thiab kev ua haujlwm ntawm cov nroj tsuag vim tias cov txheej txheem oxidation mus txog qhov kev txwv ntawm cov nplaim taws thiab propylene peroxide yog cov khoom tsis ruaj khov.
Tseem ceeb aldehydes siv nyob rau hauv zus tau tej cov sib tsoo log bonds muaj xws li formaldehyde, furfural thiab hexamethyltetramine.
Formaldehyde yog ib yam tshuaj phem uas yuav ua rau lub qhov muag, qhov ntswg thiab caj pas ua rau khaus thaum lub concentration siab tshaj ib theem. Hexamethylenetetramine, tseem hu ua hexamethylenetetramine, yog ib hom tawv tawv hauv phenolic resin bonds. Basic oxides xws li calcium oxide los yog magnesium oxide yog kho accelerators nyob rau hauv phenolic resins.
Txoj kev catalytic thiab molar piv ntawm phenol rau aldehyde ua rau seb cov resin yog hom resole lossis hom novolak. Resoles tuaj yeem kho tau yooj yim los ntawm cov kua qaub, alkali lossis cua sov; novolaks yog kho los ntawm formaldehyde nrog hexamethyltetramine, khoom resoles lossis lwm txoj kev. Resoles tuaj yeem yog cov khoom resole, resole daws los yog dej-raws li resole; novolaks tuaj yeem yog cov khoom siv cob, cov tshuaj novolak, dej-raws li novolak dispersion thiab hmoov resin uas muaj hexamethyltetramine. Rau kev tsim cov cuab yeej abrasive, dej-raws li resole thiab hmoov novolak yog cov ntaub ntawv tseem ceeb tshaj plaws.
1.2 Phenolic resins
Phenolic resin daim ntawv cog lus rau kev sib tsoo log muaj cov kua (resole) thiab hmoov (novolak), ncaj qha thiab hloov kho phenolic resins, hmoov resins nrog cov neeg ua dej ntub dej, los yog kev sib txuas ntawm cov phenolic resins uas muaj cov hmoov phenolic resins. Kev hloov kho ntau yam tuaj yeem ua tau, xws li nrog epoxy resins, roj hmab, polyvinyl butyral, thiab lwm yam. Tsis tas li ntawd, phenolic resin bonds rau superabrasives yog ntxiv nrog SiC hais thiab cov khoom lubricants. Phenolic resins kho ntawm li 150-200 degree los ntawm polycondensation. Cov ncauj lus kom ntxaws ntawm cov kua thiab cov hmoov resin rau kev tsim cov abrasives yog muab los ntawm Gardziella li al.
1.3 Polyamide thiab polyimide resins
Polyimides yog cov polymers uas tsis muaj cov pa roj carbon nitrogen hauv ib qho ntawm cov nplhaib hauv cov saw hlau molecular. Polyamide-imides yog cov tswv cuab ntawm tib tsev neeg polymer thiab muaj cov nplhaib uas muaj ntxhiab thiab cov nyiaj nitrogen.
Polyimide thiab polyamide-imide qauv
Polyamide thiab polyimide bonds muaj zog dua, thermal kuj thiab elasticity dua phenolic resin bonds. Polyimide bonds yog 5 mus rau 10 lub sij hawm tawv dua phenolic bonds thiab tuaj yeem tiv taus qhov kub ntawm 300 degree rau 20 npaug ntev dua. Txawm li cas los xij, tus nqi siab dua txwv tsis pub siv hom kev sib txuas no rau cov ntawv thov tshwj xeeb thiab superabrasives. Polyimide resins yog hom kev sib cog lus tseem ceeb rau kev sib tsoo carbide siab, tshwj xeeb tshaj yog rau kev sib tsoo, los yog txiav tawm kev sib tsoo hauv qab txias lubricants.
1.4 Epoxy los yog polyurethane resins
Epoxy los yog polyurethane log yog cov softest ntawm resin-bonded log. Rau cov pa abrasives, lawv feem ntau siv rau ob-disc thiab cylindrical sib tsoo. Txawm li cas los xij, rau superabrasives, epoxy lossis polyurethane daim ntawv cog lus zoo li txwv rau cov ntawv thov nrog cov pob zeb diamond micron hauv iav thiab ceramic industries. Cov yam ntxwv ntawm epoxy resins yog lawv pawg epoxy, uas muaj lub nplhaib epoxide (–CH2–O–CH2–). Tom qab ntawd cov epoxy resin yog hardened rau ib tug polymer nrog ib tug kua hardener.
