Residual stress analyses in cutting tools coated by CVD

• Grant number: 17/14386-9
• Support Opportunities: Scholarships in Brazil - Master
• Effective date (Start): October 01, 2017
• Effective date (End): July 31, 2018
• Field of knowledge: Engineering - Materials and Metallurgical Engineering
• Principal Investigator: Haroldo Cavalcanti Pinto
• Grantee: Maiara Fernanda Moreno
• Host Institution: Escola de Engenharia de São Carlos (EESC). Universidade de São Paulo (USP). São Carlos , SP, Brazil

Abstract

This research project aims at investigating the residual and thermal stress behavior of thin films in coated cutting tools used in milling applications, which are subjected to thermo-mechanical cycles during their tool life. Typical wear limitation is the formation of comb cracks on the cutting edge, which lead to chipping and failure of the tools. The resistance to comb cracks depends on the ability of the coated tools to reduce the formation and propagation of comb cracks, which are originated in the coating and propagate into the carbide. By adjusting the residual/thermal stress condition of the coating/carbide substrate (which depends among others on the composition of the thin film layers, the processing method, the pre- or post-treatment) the resistance to comb crack failure can be improved. Thus in this work stress analyses will be carried out using X-ray diffraction in coated carbides with Ti(C,N)/k-Al2O3 and Zr(C,N)/k-Al2O3 based systems produced by chemical vapor deposition(CVD). The thermal stresses will be analyzed "in situ" at cycling temperature conditions ranging from room temperature to 800ºC in order to verify the influence of the different systems on the internal stress evolution and behavior of the composites. In addition, the influence of different post-treatment processes (such as micro-blasting or brushing) on the residual/thermal stress of the thin films will be investigated. The results are valuable for understanding the behavior of thin films at cycling temperatures and also to design novel systems with enhanced resistance to comb cracks. (AU)

Academic Publications

(References retrieved automatically from State of São Paulo Research Institutions)

MORENO, Maiara Fernanda. In situ study of residual stress evolution in Zr(C,N)/α-Al2O3 and Zr(C,N)/κ-Al2O3 CVD multilayers during thermal cycling. 2019. Master's Dissertation - Universidade de São Paulo (USP). Escola de Engenharia de São Carlos (EESC/SBD) São Carlos.