تحليل تجربي فرآيند پوشش دهي كامپوزيت نيكل - كاربيد تيتانيوم به كمك ليزر و محاسبه ميدان تنش و دما به روش اجزاي محدود

چكيده انگليسي :

Experimental Analysis of Laser Cladding of Ni TiC Composite andCalculation of Stress and Temperature Fields by Finite Element Method Ali Alirezaie Dizicheh a alirezaie@me iut ac ir Department of Mechanical Engineering Isfahan University of Technology Isfahan 84156 83111 IranDegree M Sc Language FarsiSupervisors Mohammad Mashayekhi mashayekhi@cc iut ac ir Mohsen Badrossamay Mohsen badrossamay@cc iut ac irAbstractSince cladding operation improves the function of the part s surface in addition to itsuseful life enhancement it increases the parts value Nowadays utilizing the metal ceramic composite coatings is highly noticed by a lot of industries and it s because of thehigh thermal resistance high wearing resistance high strength of the ceramics and alsoductility and toughness of the metals Moreover unique property can be achieved bycombination of them The composite coatings are often used in order to wearing andcorrosion resistance enhancement Laser cladding process is one of the surface claddingmethods which is applied by many industries In this process part of the laser beam senergy is absorbed by the cladding powder and results the powder s melting beforereaching the substrate another part of the energy melts a thin layer of the substrate andtherefore a powerful bond is developed between the coating and the substrate in additionto the least dilution In the present work finite element and experimental investigationhave been done on laser cladding process In the experimental part of this investigation the essential equipment of this process such as designing and making of the dual powerfeeder and characterization the cladding head is provided Because of the low power inutilizing the CO2 laser it s not possible to develop the coatings with suitable width Byapplying the Nd YAG laser the appropriate parameters are determined with proper widthand thickness Titanium Carbide cladding composite is developed under metallographyand mechanical tests with different percentages of hard phases The results show that theTitanium Carbide particles are spread out through the nickel matrix Because of theparticles lightness the spread of these particles is also more on the surface Wear testresults show that the coating s wear resistance and its friction is reduced by increasing theamount of Titanium Carbide The coating s hardness is increased by increasing the hardphase percentage In the finite element part of this investigation the laser cladding processis modeled in order to determining the thermal and stress distribution For simulating theelement birth and death technique is used A customized 3 D finite element model hasbeen developed incorporating these effects based on simulation of conductive convectiveand radiative heat transfer and assuming elastic perfectly plastic deformation behavior Creep effects have been neglected and the cladding particulate metal matrix composite has been treated as a continuum Comparisons are presented between measured andsimulated thermal fields and specimen deflection histories The results show that curvatureis decreased by increasing the coating s Titanium Carbide percentage The residual stressin the coating is compressive and will be increased by increasing the amount of TitaniumCarbide Also the residual stress is constant along the cladding Keywords Laser cladding Powder feeder Metal ceramic composite Nickel TitaniumCarbide Wear test Finite element Element birth and death

عليرضايي ديزيچه، علي

تحليل تجربي فرآيند پوشش دهي كامپوزيت نيكل - كاربيد تيتانيوم به كمك ليزر و محاسبه ميدان تنش و دما به روش اجزاي محدود

دستگاه تغذيه ي پودر , هد پوشش دهي , آزمون سايش , فعال و غير فعال شدن المان