A constitutive model for glass–ceramic materials

Journal Article · Sat Mar 27 00:00:00 EDT 2021 · Mechanics of Materials

DOI:https://doi.org/10.1016/j.mechmat.2021.103849· OSTI ID:1778031

Lester, B. T. ^[1]; Long, K. N. ^[1]

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1. Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

Glass–ceramics have received recent attention for use in glass–ceramic to metal hermetic seals. Due to their heterogeneous microstructure, these materials exhibit a number of advantageous responses over conventional glass based seals. Key amongst them is the possibility of a controllable thermal strain response and apparent coefficient of thermal expansion which may be used to minimize thermally induced residual stresses for aforementioned seals. Furthermore, these behaviors result from an inorganic glass matrix and variety of crystalline ceramic phases including silica polymorph(s) that may undergo reversible solid-to-solid transformations with associated inelastic strain. Correspondingly, these materials exhibit complex thermomechanical responses associated with multiple inelastic mechanisms (viscoelasticity and phase transformation). While modeling these behaviors is essential for developing and analyzing the corresponding applications, no such model exists. Therefore, in this work a three-dimensional continuum constitutive model for glass–ceramic materials combining these various inelastic mechanisms is developed via an internal state variable approach. A corresponding fully implicit three dimensional numerical formulation is also proposed and implemented. The model is used to simulate existing experiments and validate the proposed formalism. As an example, the simple seal problem of a glass–ceramic seal inside a concentric metal shell is explored. Finally, the impact of the cooling rates, viscoelastic shift factors, and inelastic strain on final residual stress state are all investigated and the differing contributions highlighted.

• Research Organization: Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States)
• Sponsoring Organization: USDOE National Nuclear Security Administration (NNSA)
• Grant/Contract Number: AC04-94AL85000; NA0003525
• OSTI ID: 1778031
• Alternate ID(s): OSTI ID: 1828410
• Report Number(s): SAND--2021-3654J; 695069
• Journal Information: Mechanics of Materials, Journal Name: Mechanics of Materials Vol. 158; ISSN 0167-6636
• Publisher: Elsevier
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
Constitutive modeling
glass-ceramics
phase transformation
residual stresses
viscoelasticity