ISSN: 0970-938X (Print) | 0976-1683 (Electronic)

Biomedical Research

An International Journal of Medical Sciences


Joint Event on Global Congress on BIOTECHNOLOGY & Annual Congress on EMERGING MATERIALS AND NANOTECHNOLOGY
September 06-07 , 2018 | Bangkok , Thailand

A D Chandio

NED University of Engineering and Technology, Pakistan

Posters & Accepted Abstracts : Biomed Res

DOI: 10.4066/biomedicalresearch-C4-011


Bond coats (BCs) based on βNiAl matrix are commonly employed in thermal barrier coating systems (TBC) for aero-engine applications. The addition of reactive elements (REs) such as; Zr, Hf and Y in βNiAl are being researched extensively since they offer improved oxidation performance at high temperatures. In this study, experimental findings will be presented on the βNiAl matrix-based BCs that were prepared onto CMSX-4 superalloy with and without additions of Zr and Hf using an in-situ chemical vapor deposition (CVD) method. The BCs were isothermally oxidized at 1150oC for 100 hours in laboratory air. The processing of REs-βNiAl and their effects on oxidation were studied in comparison to undoped βNiAl. This was followed by characterization techniques including TEM, FIB, ASTAR analysis; SEM, XRD, Proto iXRD and Raman spectroscopy/PLPS. The REs doped βNiAl were successfully prepared using in-situ CVD technique. BC performance is discussed in detail such as thermally grown oxide (TGO) phases, stresses, morphologies etc. In general, TGO formed due to oxidation of REs doped samples consisted of alpha alumina alone; on contrary mixture of TiO2, NiAl2O4, θ-Al2O3 and α-Al2O3 was seen in their undoped counterparts. In addition, the TGO growth rate and residual stresses on REs- βNiAl were found to be lower than that of the undoped βNiAl. In addition, oxide pegging (OP) due to REs were also analyzed using TEM with the aid of FIB this was followed by ASTAR indexing. The OP was emerged to be one of key features of REs doped BCs which is crtical factor for lifespan of the TBC.