Advanced characterization through TEM of FIB prepared samples of nanocrystalline alloy coatings produced by thermal spray and laser cladding

Abstract

The surface treatments through laser that result in phase transformations solid state and the production of coatings for advanced applications in order to improve wear and corrosion resistance, are characterized as one of the main materials processing alternatives that brings together the possibility of obtaining, refined microstructures, metastable, nano and quasicrystalline and amorphous structure, with significant improvements in properties of metallic alloys when compared with commercial alloys or crystalline slowly solidified though conventional metallurgical processing routes. The objective of this project is the sample preparation for transmission electron microscopy (TEM) through focused ion beam (FIB) of Nanocrystalline Alloys Coatings produced by Thermal Spray and Laser Cladding from atomized powders. It will be studied the micro and nanostructure of coatings (and its interface with substrate) of Fe-, Ni-Nb, Cu-Zr, Al- and Ti-based Nanocrystalline Alloys atomized powders, using Thermal Spray and Laser Cladding, and it respective microstructure characterization. The characterization techniques used in this work will be X-ray diffraction (XRD), thermal analysis (DSC), scanning (SEM) and transmission electron microscopy (TEM) coupled to energy dispersive spectroscopy (EDS). Nanohardness measurements will be used for evaluation of nanohardness and Young modulus (GPa) of the coatings and interface with substrate. The execution of this proposal will be associated to a "Thematic" Project of FAPESP (Nº: 2013/05987-8) in our research group Lab (Amorphous and Nanocrystalline Alloys) the possibility de establish a new research area at the DEMa/UFSCar regarding materials processing through Laser.