Driving force for indentation cracking in glass: composition, pressure and temperature dependence.

Area of Science:

• Materials Science
• Solid Mechanics
• Glass Science

Background:

• Surface damage on glass parts from sharp contact loading is a significant industrial problem.
• The mechanisms of microcracking and fracture toughness in glass remain poorly understood.
• Predicting crack initiation and damage extent is challenging due to limited knowledge of glass composition effects.

Purpose of the Study:

• To investigate the microcracking behavior of different glass compositions under sharp contact loading.
• To elucidate the contributions of rheological processes (elasticity, densification, shear flow) to surface imprint formation.
• To develop a predictive model for microcrack type and extent based on glass physical properties.

Main Methods:

• Comparative analysis of glass behavior across diverse chemical systems.
• Experimental identification of rheological contributions to indentation imprint.
• Correlation of microcracking patterns with glass composition and physical properties.

Main Results:

• Distinct microcracking patterns observed, dependent on glass composition.
• Identification of elasticity, densification, and shear flow as key factors influencing crack formation.
• A straightforward prediction of microcrack type and extent is achieved based on glass properties.

Conclusions:

• Glass surface damage prediction is feasible by understanding rheological processes and physical properties.
• Guidelines for reducing microcracking susceptibility are proposed, considering composition, temperature, and pressure.
• Further research is needed to refine fracture criteria and predictive models for glass damage.