Determination of the Crack Initiation and Propagation Energies during Instrumented Indentation of Brittle Materials and Hardening Coatings

• Published in: Russian metallurgy Metally 2024, Vol.2024 (2), p.472-477
• Main Authors: Matyunin, V. M., Marchenkov, A. Yu, Petrova, M. P., Zilova, O. S., Pan’kina, A. A., Sviridov, G. B.
• Format: Article
• Language: English
• Subjects: Apexes; Brittle fracture; Brittle materials; Chemistry and Materials Science; Coatings; Crack initiation; Crack propagation; Cracking (fracturing); Critical point; Diagnostics and Mechanical Test Techniques; Fracture toughness; Hardening; Indentation; Materials Science; Metallic Materials; Parameter estimation; Propagation; Stress intensity factors; Stress propagation; Surface layers
• ISSN: 0036-0295; 1555-6255; 1531-8648
• DOI: 10.1134/S0036029524700824

The well-known methods of determining the critical stress intensity factor K I c of the surface layers of materials by indentation of a pyramid for the formation of radial cracks propagating from the vertices of an indent are considered. It is noted that the existing methods for estimating the fracture toughness of a material by indentation do not allow one to determine the crack initiation energy. A technique is proposed to determine the specific crack initiation energy and the specific crack propagation energy using the critical points of a pyramid indentation diagram during instrumented indentation. Energy fracture toughness criterion G I c is found to be related to specific crack propagation energy ω p , which is determined using an indentation diagram, for brittle materials and hardening coatings. This finding makes it possible to develop a technique for rapid estimation of critical stress intensity factor K I c using an indentation diagram recorded during instrumented indentation without measuring the geometric parameters of formed cracks and regardless of their type.