Silicon nitride (Si3N4) yog cov khoom siv hluav taws xob ua haujlwm siab uas nthuav tawm cov khoom siv kho tshuab zoo, ua rau nws muaj kev xaiv nrov rau ntau yam kev siv engineering. Nws qhov tshwj xeeb ua ke ntawm lub zog, toughness, thiab thermal stability ua rau nws sib nrug los ntawm lwm cov ceramics, thiab nws cov khoom siv tshuab ua lub luag haujlwm tseem ceeb hauv kev txiav txim siab nws qhov tsim nyog rau cov ntawv thov tshwj xeeb.
1. Hardness
Silicon nitride muaj npe nrov rau nws qhov tshwj xeeb hardness, uas yog qhov siab tshaj plaws rau cov ntaub ntawv ceramic. Nws qhov hardness feem ntau yog nyob rau hauv thaj tsam ntawm 1400 txog 1600 Vickers, ua rau nws nyuaj dua li ntau cov khoom siv hlau thiab tsis yog xim hlau. Qhov siab hardness no yog tshwm sim los ntawm cov muaj zog covalent bonds ntawm silicon thiab nitrogen atoms nyob rau hauv nws cov qauv siv lead ua. Lub hardness ntawm silicon nitride pab txhawb rau nws hnav tsis kam, ua rau nws haum rau daim ntaub ntawv uas abrasive hnav yog ib qho kev txhawj xeeb.
2. Lub zog
Ib qho ntawm cov khoom tseem ceeb ntawm silicon nitride yog nws lub zog zoo. Nws muaj lub zog flexural siab, feem ntau tshaj 1000 MPa, thiab lub zog tensile nyob rau hauv thaj tsam ntawm 600 txog 900 MPa. Lub zog siab no yog ntaus nqi rau cov qauv siv lead ua muaj zog ntawm silicon nitride, nrog rau nws lub peev xwm los tiv thaiv kev tawg tawm. Kev sib xyaw ua ke ntawm kev ua haujlwm siab thiab lub zog ua rau silicon nitride haum rau cov ntawv thov uas xav tau cov qauv kev ncaj ncees thiab ua haujlwm rau cov khoom siv tshuab.
3. Fracture Toughness
Ntxiv nrog rau nws lub zog siab, silicon nitride nthuav tawm cov pob txha zoo heev. Fracture toughness yog hais txog cov khoom muaj peev xwm tiv thaiv kev tawg tawm thiab tiv thaiv qhov pib ntawm pob txha. Silicon nitride lub pob txha toughness yog feem ntau nyob rau hauv thaj tsam ntawm 5 mus rau 7 MPa√m, uas yog ho siab tshaj ntau lwm yam ceramics. Cov cuab yeej no yog qhov tseem ceeb rau cov ntawv thov uas cov khoom raug cuam tshuam rau kev thauj khoom lossis kev cuam tshuam, vim nws txhim kho cov khoom muaj peev xwm nqus tau lub zog thiab tiv thaiv kev puas tsuaj loj.
4. Thermal stability
Silicon nitride tswj nws cov khoom siv kho tshuab ntawm qhov kub thiab txias, ua rau nws tsim nyog rau cov ntawv thov hauv qhov xav tau cua sov. Nws muaj cov thermal conductivity siab, ua kom cov cua sov ua kom zoo, thiab tuaj yeem tiv taus qhov kub siab tshaj 1000 degree. Qhov kev ruaj ntseg thermal no yog qhov tseem ceeb rau cov ntawv thov xws li cov cuab yeej txiav, pob bearings, thiab cov khoom siv cav, qhov uas raug rau qhov kub siab heev.
5. Thermal Expansion
Thaum silicon nitride nthuav tawm cov thermal stability zoo, nws cov coefficient qis ntawm thermal expansion yog lwm cov cuab yeej cuab tam tsis zoo. Qhov qis thermal expansion ntawm silicon nitride pab txo qhov kev pheej hmoo ntawm thermal kev ntxhov siab thiab tawg thaum cov khoom raug hloov pauv sai. Cov cuab yeej no muaj txiaj ntsig zoo nyob rau hauv cov ntawv thov uas qhov kub hloov pauv tau nquag lossis siab heev.
6. Tshuaj Inertness
Silicon nitride yog chemically inert, txhais tau tias nws tiv taus corrosion thiab tshuaj tua kab mob. Cov cuab yeej no ua rau nws tsim nyog rau cov ntawv thov hauv ib puag ncig tshuaj lom neeg hnyav uas lwm cov ntaub ntawv yuav degrade dhau sijhawm. Cov tshuaj inertness ntawm silicon nitride txhim kho nws cov kav ntev thiab kev ntseeg siab hauv kev ua haujlwm nyuaj.
Nyob rau hauv xaus, silicon nitride boasts zoo heev mechanical zog uas ua rau nws ib tug ntau yam thiab txhim khu kev qha cov ntaub ntawv rau ntau yam kev siv. Cov kws tsim qauv thiab cov kws tsim qauv txuas ntxiv mus tshawb nrhiav txoj hauv kev tshiab los siv cov khoom siv tshwj xeeb ntawm silicon nitride txhawm rau txhim kho thev naus laus zis thiab daws cov teeb meem tshwm sim los ntawm kev xav tau kev ua haujlwm.
