Characterization of the AlCr Thermal Barrier Coatings for IN 738 Ni-base Super alloys Used in High Temperature Applications

Abstract

In this research a study on Nickel-Based Superalloys (Grade IN 738) coated by slurry coating technique have been done. Al-Cr layer of coatinghad been applied with four percentages. PVA bonding material had been used with percentage of 1: 10 of deionized water.X-ray Diffraction and Scanning Electron Microscope have been used in order tocharacterize the coating layer. SEM images showed the homogenous distribution of the coating layer on the surface of Inconel base material. XRD characterize the chemical composition of the coating layer; which it formed on the surface after mixed it with the bonding material. The main goal of this research is to characterize the coating features by using XRD and SEM examinations, and also measuring the hardness increasing rate after applying the coating layer.The aim of this work is to deposit chromium and aluminium simultaneously on the surface of IN 738 alloy, using a slurry process.Furthermore, this study is planned to improve the hardness by increasing the amount of chromium and aluminium at the surface of IN 738 alloy. This is related to the formation of an external scale of mainly Cr₂Al due to the high volume fraction of Cr present.