پديد آورنده :
حسيني، رحمان
عنوان :
محاسبه، اندازگيري وتحليل نفوذ نيتروژن در فرايند نيتروژن دهي پلاسمايي
محل تحصيل :
اصفهان: دانشگاه صنعتي اصفهان، دانشكده مواد
صفحه شمار :
هيجده، 177، [II]، ص: مصور ، جدول، نمودار
يادداشت :
ص.ع. به: فارسي و انگليسي
استاد راهنما :
فخرالدين اشرفي زاده
استاد مشاور :
احمد كرمانپور
توصيفگر ها :
محاسبه تحليلي , نيتروژن دهي پلاسمايي , آهن خالص , نيم رخ توزيع غلظت نيتروژن , ضخامت لايه هاي تركيبي , ناحيه نفوذي , طيف سنجي نشر نوري با منبع پلاسمايي ﴿GDOES) , طيف سنجي جرمي يون ثانويه﴿SIMS)
تاريخ نمايه سازي :
88/4/23
استاد داور :
فرزاد محبوبي، محمود حيدر زاده سهي، محمد علي گلعذار
كد ايرانداك :
ID245 دكتري
چكيده فارسي :
به فارسي و انگليسي: قابل رويت در نسخه ديجيتال
چكيده انگليسي :
Calculation Measurement and Evaluation of the Nitrogen Diffusion in Plasma Nitriding Process Saied Rahman Hosseini hosseinisr@ma iut ac ir May 02 2009 Department of Materials Engineering Isfahan University of Technology Isfahan 84156 83111 IranSupervisor Prof F Ashrafizadeh1 ashrafif@cc iut ac irAdvisor Assoc Prof A Kermanpur1Department Graduate Coordinator Assoc Prof M Shamanian1AbstractCalculation measurement and evaluation of nitrogen diffusion in plasma nitriding processwere carried out Analytical models for nitrogen concentration distribution and compoundlayer growth were derived by applications of calculations on the diffusion laws Thecompound region was considered as two separated layers including epsilon and gammaprime nitrides as well as a diffusion zone The analytical models were constructedbased on the binary Fe N phase diagram below 592oC and up to 11wt nitrogen Considering relevant initial and boundary conditions the Fick s second diffusion law wasused for three separated and zones in a semi infinite domain Three nitrogenconcentration equations in and phases were obtained versus nitriding temperature timeand diffusion distance Using the Fick s first diffusion law and mass conservation rule twoequations were developed for predicting thickness of the and layers versus nitridingtemperature and time Plasma nitriding was carried out on pure iron substrate at 550oC in anH2 N2 atmosphere for various nitriding periods Optical microscopy and SEM for structuralevaluation microhardness for hardness profiling profilometer for roughness measurements XRD for phase analysis EDS for semi quantitative elemental analysis GDOES forquantitative elemental depth profiling and SIMS for detection of nitrogen within the diffusionzone were employed to characterize nitrided samples The calculated results were comparedwith the experimental data and a good agreement was achieved The results showed thatslope of the equations which represents growth rate of the compound layer is different forand nitrides at each nitriding temperature In plasma nitriding process opposite to gaseousnitriding thickness of is much lower than that of nitride Using correction factors theequations were modified for application in various nitriding conditions It was found that thegrowth rate of both layers is high and increased at the primary stages of nitriding process butgradually decreased and reached to the steady state condition Increasing nitridingtemperature leads to increasing the maximum nitrogen concentration at the interface higher nitrogen distribution in zone and deeper diffusion in the substrate At a certainnitriding temperature increasing nitriding time up to 10 h has a significant effect on thenitrogen distribution but longer periods have no considerable influence The extent ofnitrogen diffusion depth reached to several hundred of micrometers at primary stage of theprocess It was increased to values in excess of 1500 m for 10 h plasma nitriding at 550oC Such values calculated and measured accurately for the first time in this work by SIMStechnique have not been reported in previous investigations Key WordsAnalytical calculation Plasma nitriding Nitrogen diffusion Nitrogen depth profile Compound layer thickness Diffusion zone GDOES SIMS 1 Department of Materials Engineering Isfahan University of Technology Isfahan 84156 83111 Iran
استاد راهنما :
فخرالدين اشرفي زاده
استاد مشاور :
احمد كرمانپور
استاد داور :
فرزاد محبوبي، محمود حيدر زاده سهي، محمد علي گلعذار
