| This research study involves the application of Laser Additive Manufacturing(LAM)technique in the repair and solving of an engineering problem caused by abrasion and subsequent tip deformation and wearing out of the outer surface of the Inconel 718 turbo fan component.An extensive set of LAM experiments and analysis with various laser power,cladding speed and powder mass flow rate have been performed with an objective of applying the optimal laser additive manufacturing process parameters conditions in relation to surface temperature measured during cladding.The mechanical properties of Inconel 718 mainly micro hardness test,metallurgical properties,clad geometry and qualitative properties(i.e.porosity and cracking of the cladded layer)was further investigated to optimize the parameters attained by the results achieved by pyrometry infrared temperature measurement.The techniques applied.include,surface and melt pool temperature monitoring,Vickers micro hardness tester at a load of 300g and 500g with a dwell time of 15 seconds,simulation data,evaluation of the microstructure,surface alloying using boron and heat treatment.A two color pyrometer based in situ temperature monitoring system as well as moving with the laser head during the LAM process was developed and real time temperature data was recorded.The cooling rate,temperature profile,multilayer clad deposition and their relationship with the metallurgical properties was achieved and evaluated.The optimal laser additive manufacturing process parameters which eliminated clad porosity,cracks,achieved a good bound to the substrate,favorable microstructure and hence provided a basis for the repair of Inconel 718 turbofan was determined.From the study,the cooling rate is directly proportional to the scanning speed,inversely proportional to the input power and increase in the clad layer resulting in finer microstructure which are necessary for the repair of Inconel 718 turbofan. |
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