CHARACTERIZATION OF EXTRUDED SAMPLES OF Fe-Co-B-Si-Nb SYSTEM BY COMPUTED TOMOGRAPHY AND TRANSMISSION ELECTRON MICROSCOPY

• Grant number: 17/09343-9
• Support Opportunities: Scholarships abroad - Research Internship - Master's degree
• Start date: August 01, 2017
• End date: January 31, 2018
• Field of knowledge: Engineering - Materials and Metallurgical Engineering - Physical Metallurgy
• Principal Investigator: Claudio Shyinti Kiminami
• Grantee: Diego de Araujo Santana
• Supervisor: Michael Joseph Kaufman
• Host Institution: Centro de Ciências Exatas e de Tecnologia (CCET). Universidade Federal de São Carlos (UFSCAR). São Carlos , SP, Brazil
• Institution abroad: Colorado School of Mines, United States
• Associated to the scholarship: 15/26705-6 - Fabrication of bulk amorphous Fe-Co-B-Si-Nb alloy by atomization and hot extrusion route, BP.MS

Abstract

Metallic glasses when heated in supercooled liquid region show high viscous flowability and their viscosity decreases significantly in that state. This feature allows the consolidation of metallic glasses in bulk samples with dimensions of several millimeters or centimeters. The central goal of the student master dissertation is to produce bulk sample with diameter over than 4 mm with amorphous structure by route of consolidation of amorphous powders by hot extrusion. The main parameters in extrusion process are ram speed, extrusion ratio and extrusion temperature. For a critical analysis of those parameters an evaluation of extruded samples with respect to porosity, bonding state between the particles and presence of nanocrystalline particles disperse in amorphous matrix are required. In this sense, the goal of present project at CSM is do a detailed mapping of extruded bodies with respect to porosity and crystalline phases by using computed tomography and transmission electron microscopy techniques, respectively. Based on the results found, the influence of porosity and nanocrystals on the mechanical properties of the consolidated samples will be checked and each region of the sample will be correlated with the shear deformation and local temperature during extrusion.