Development of functionally graded materials composed of niobium carbide and 304 stainless steel with addition of and molybdenum carbide

• Grant number: 20/08812-8
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: September 01, 2020
• End date: October 31, 2021
• Field of knowledge: Engineering - Materials and Metallurgical Engineering - Nonmetallic Materials
• Principal Investigator: Vera Lucia Arantes
• Grantee: Lucas Alexandre Morais
• Host Institution: Escola de Engenharia de São Carlos (EESC). Universidade de São Paulo (USP). São Carlos , SP, Brazil

Abstract

Cutting tools are of great importance for the industrial manufacturing area, since directly influence the economy of machining industries. To be used, cutting tool inserts must have characteristics that guarantee a good functioning, such as high hardness and fracture toughness. To obtain better mechanical properties, studies suggest the use of grain growth inhibitors in these tools. There is evidence that molybdenum carbide is one of the most effective inhibitors. Knowing the importance that cutting tool inserts exert, and considering the progress in technology and the growing interest in functionally graded materials (FGMs), added to the scarcity of information on this subject, the present project aims to develop heterogeneous FGMs cermets of niobium carbide with 304 stainless steel binder and molybdenum carbide as a grain growth inhibitor for cutting tools. In this research project, for the manufacture of the cermets, the co-pressing process will be used to produce the FGMs samples, in which, by the molybdenum carbide gradation, it is expected that there will be gradual variations in the mechanical properties, concentrating the hardness on the surface which is responsible for performance, lifetime or wear, and at the same time, high fracture toughness in the center of the insert, able to withstand the stresses that occur during cutting. In the laboratory, tests will be performed on six samples with different chemical compositions of gradation. During the experiments, the mechanical properties of the samples will be analyzed through optical and mechanical characterization, and with the results, it will be possible to infer the viability of this FGMs cermet for cutting tool inserts and the possible replacement of the WC-Co cermets, where studies show that this material presents problems such as being toxic to humans, scarcity of raw material, and high cost.