吉大材料考研課件全英語版chapter

Chapter6

Diffusion第六章擴散吉林大學(xué)材料科學(xué)與工程學(xué)院曹占義2023/3/27Chapter6Diffusion26.1INTRODUCTIONdiffusion:Masstransportbyatomicmotion.Interdiffusion(orimpuritydiffusion):

Diffusionofatomsofonemetalintoanothermetal.Self-diffusion:Atomicmigrationinpuremetal.擴散異(互)擴散自擴散2023/3/27Chapter6Diffusion36.1INTRODUCTIONInterdiffusionofCu-Nicouple:

銅鎳的異(互)擴散2023/3/27Chapter6Diffusion46.2DIFFUSIONMECHANISMSVACANCYDIFFUSION.INTERSTITIALDIFFUSION.

空位擴散間隙原子擴散2023/3/27Chapter6Diffusion56.3STEADY-STATEDIFFUSIONdiffusionflux(J)微分形式steady-statediffusion2023/3/27Chapter6Diffusion66.3STEADY-STATEDIFFUSIONFick’sfirstlaw菲克第一擴散定律Diffusioncoefficient,DDrivingforce擴散系數(shù)，穩(wěn)態(tài)擴散時的擴散速度（擴散）驅(qū)動力2023/3/27Chapter6Diffusion76.4NONSTEADY-STATEDIFFUSIONFick’ssecondlaw菲克第二擴散定律如果擴散系數(shù)不受成分影響，則：2023/3/27Chapter6Diffusion86.4NONSTEADY-STATEDIFFUSIONASolutionofFick’ssecondlawforasemi-infinitesolid菲克第二擴散定律boundaryconditionsHere:Equation6.52023/3/27Chapter6Diffusion96.4NONSTEADY-STATEDIFFUSIONASolutionofFick’ssecondlawforasemi-infinitesolid菲克第二擴散定律的應(yīng)用Equation6.5C1D12023/3/27Chapter6Diffusion106.5FACTORSTHATINFLUENCEDIFFUSIONDIFFUSINGSPECIES:TEMPERATURE:

擴散(偶)種類溫度2023/3/27Chapter6Diffusion116.6OTHERDIFFUSIONPATHS‘‘short-circuit’’diffusionpathsdislocations,grainboundaries,andexternalsurfaces2023/3/27Chapter6Diffusion126.7DIFFUSIONINIONICANDPOLYMERICMATERI