5474

5134

كارشناسي ارشد

شناسايي و انتخاب مواد

اصفهان: دانشگاه صنعتي اصفهان، دانشكده مواد

1389

نه،79ص.: مصور،جدول،نمودار

ص.ع.به فارسي و انگليسي

مرتضي شمعانيان، فخرالدين اشرفي زاده

24/7/89

حميدرضا سليمي جزي، سعيدرضا بخشي

مهندسي مواد

ID5134

به فارسي و انگليسي: قابل رويت در نسخه ديجيتالي

80 Formation of Ni Ti C composite coatings on Austenitic stainless steel by welding and Evaluating wear behavior Foad Ghaeni Email address f ghaeni@ma iut ac ir Date of Submission 2010 05 22 Department of Materials Engineering Isfahan University of Technology Isfahan 84156 83111 Iran Language Farsi Degree M Sc Supervisor s Name Morteza Shamanian Associate Professor shamanian@cc iut ac ir Fakhreddin Ashrafizadeh Professor ashrafif@cc iut ac ir Abstract The formation of Ni Ti intermetallic coatings reinforced by TiC particles on AISI 304 stainless steel surface using Ni Ti C elemental powder mixtures via GTAW process has been studied in this research The elemental powder mixtures with calculated stochiometric proportions were milled as first step Then those mixtures were pressed to form a bricket called filler alloy and subsequently melted on steel substrate using GTAW process The microstructure and phase structure of specimens were studied using optical microscope and SEM and XRD respectively The micro hardness of specimens were measured using Vickers indentor and wear tests were done using pin on disc method The results show that milling and subsequent GTAW melting of Ni Ti powder mixtures lead to formation of dual phase NiTi Ni3Ti structure which have thickness of 1 5 mm with hardness degree of at least 600 Hv while same process using Ni Ti C powder mixture lead to formation of dual phase NiTi Ni3Ti structure containing TiC particles which have excessive thickness of 100 to 300 HV depending on the reinforcing phase content The formation of these phases were analyze dusing process kinetics and equilibrium phase diagram of Ni Ti and were compared by the microstructures of coatings The analyses results reveal that the formation of TiC in these coatings is prior to the formationof Ni Ti intermetallics TiC also has an important effect on the location and constitution of intermetallic phases by depleting Ti atoms of adjacent regions Evaluating wear behavior of coatings reveals that the addition of TiC in matrix has a conspicuous effect on decreasing the mass loss during wear tests It seems that abrasive wear is the dominant mechanism in wear of unreinforced coatings and its role decreases with addition of TiC to the matrix Keywords Ni Ti intermetallics weld overlay Intermetallic Matrix Composite

مرتضي شمعانيان، فخرالدين اشرفي زاده

حميدرضا سليمي جزي، سعيدرضا بخشي