Thermally strengthened architectural glass and related systems and methods

A window comprising:

• a first glass-based layer comprising first and second major surfaces, a first body formed from a first glass material, and a first outer edge;
• a second glass-based layer comprising first and second major surfaces, a second body formed from a second glass material, and a second outer edge;
• the second glass-based layer spaced apart from and disposed substantially parallel to the first glass-based layer by a first distance;
• the first and second major surfaces of the second glass-based layer separated by the thickness t, the first major surface of the second glass-based layer being flat to 100 μm total indicator run-out (TIR) along any 50 mm or less profile of the first major surface;
• the second glass material having a low temperature linear CTE, expressed in 1/° C., of αSCTE, a high temperature linear CTE, expressed in 1/° C., of αLCTE, an elastic modulus, expressed in GPa, of E, a strain temperature, expressed in units of ° C., of Tstrain, and a softening temperature, expressed in units of ° C., of Tsoft;
• the first major surface of the second glass-based layer having a thermally induced surface compressive stress of less than 600 MPa and greater than
• P
• 1
• ⁡
• (
• h
• )
• *
• t
• (
• P
• 2
• ⁡
• (
• h
• )
• +
• t
• )
• ·
• E
• ·
• [
• T
• strain
• ·
• α
• CTE
• s
• +
• α
• CTE
• L
• ·
• (
• T
• soft
• -
• T
• strain
• )
• ]
• ;
• in units of MPa;
• wherein P1 is given by
• 910.2
• -
• 259.2
• ·
• exp
• (
• -
• h
• 0.143
• )
• ;
• P2 is given by
• 2.53
• +
• 23.65
• (
• 1
• +
• (
• h
• 0.00738
• )
• 1.58
• )
• ;
• and h is greater than or equal to 0.020.