Proposition of a method for measuring the glass forming ability of alloys

• Grant number: 14/18671-1
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: November 01, 2014
• End date: October 31, 2015
• Field of knowledge: Engineering - Materials and Metallurgical Engineering
• Principal Investigator: Marcelo Falcão de Oliveira
• Grantee: Vinicius Antonio de Oliveira
• Host Institution: Escola de Engenharia de São Carlos (EESC). Universidade de São Paulo (USP). São Carlos , SP, Brazil

Abstract

Currently, amorphous metals are being increasingly used in industrial and research centers. Due to this fact, studies related to this area have increased in recent decades and, consequently, their applications come raising space in the technological world. However, some difficulties related to this new class of materials have been found. One of the main difficulties refers to the lack of a robust method in order to determine the ability of an alloy to whether or not turn into a glass during the cooling. Currently, the existing methods are mainly based on some thermal characteristics of the formed glass and not on the cooling process. The objective of the present work is to design a method for determining the GFA (glass formation tendency) of the material which can be used as a comparative method for different alloys upon cooling. The method will be based in amorphous parts produced from the electric arc melting under inert atmosphere and subsequent cooling in cooled copper chill, driven by vacuum suction. After the production of the material by such a process, it will be analyzed by the technique of quantitative microscopy with the aid of a software, in order to determine the volume fraction of the crystals present in the structure as a function of the glass thickness within a statistical approach. Finally, curves of volume fraction of crystals as a function of sample thickness will be plotted in order to establish a quantitative method to indicate the actual GFA of different metallic alloys.