Spray forming of high entropy alloys

• Grant number: 15/25077-1
• Support type: Scholarships in Brazil - Post-Doctorate
• Effective date (Start): April 01, 2016
• Effective date (End): September 30, 2016
• Field of knowledge: Engineering - Materials and Metallurgical Engineering - Physical Metallurgy
• Principal researcher: Claudemiro Bolfarini
• Grantee: Guilherme Zepon
• Home Institution: Centro de Ciências Exatas e de Tecnologia (CCET). Universidade Federal de São Carlos (UFSCAR). São Carlos , SP, Brazil
• Associated research grant: 13/05987-8 - Processing and characterization of amorphous, metastable and nano-structured metallic alloys, AP.TEM

Abstract

High entropy alloys (HEAs) belong to a new class of alloys whose chemical compositions are based on at least five majority elements with similar atomic fractions. Such mixture of elements results in a high mixing entropy effect, which allows the formation of multicomponent solid solutions at high temperatures. These solid solutions usually present high symmetry crystalline structure. HEAs have been attracting worldwide attention due to their microstructural characteristics and properties. The major challenge concerning the processing of HEA arises from the high segregation levels usually presented when conventional casting process is used, which makes necessary long heat treatments at high temperatures to homogenize the microstructure. Because of this, only small samples (few grams) have been obtained. This project proposes the study of the processing and mechanical properties of two spray-formed HEAs (CrMnFeNiCo and CrFeNiCoCuxAly). Recently, our research group at DEMa-UFSCar, which has unique spray forming facilities in the country, has contributed significantly to the understanding of the solidification mechanisms and microstructural evolution of spray-formed alloys, which is still an open discussion among the spray-forming scientific community. Based on the last advances of our research group concerning a new solidification model for the spray forming process, and the possibility to produce alloys with refined and homogeneous microstructure, it is proposed the production of HEAs by this process (deposits of few kilograms).