High fracture toughness glass with high center tension

A glass-based article of a composition comprising: from 48 mol% to 75 mol% SiO2, from 8 mol% to 40 mol% Al2O3, from 9 mol% to 40 mol% Li2O, from 0 mol% to 3.5 mol% Na2O, from 9 mol% to 28 mol% R2O, where R is an alkali metal and R2O comprises at least Li2O and Na2O, from 0 mol% to 10 mol% Ta2O5, from 0 mol% to 4 mol% ZrO2, from 0 mol% to 4 mol% TiO2, the glass is ion exchangeable, the range of R2O + R 'O-Al2O3-Ta2O5 + 1.5 * RE2O3-ZrO2-TiO2 is-8 mol% to 5 mol%, the range of ZrO2 + TiO2 + SnO2 is greater than or equal to 0 mol% to less than or equal to 2 mol%, the composition contains no As2O3, Sb2O3 and PbO, R' is a metal selected from Ca, Mg, Sr, Ba, Zn and a combination thereof, and RE is a rare earth metal selected from Sc, Y, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu and a combination thereof. 一种组合物的基于玻璃的制品，所述组合物包含：48摩尔％至75摩尔％SiO2，8摩尔％至40摩尔％Al2O3，9摩尔％至40摩尔％Li2O，0摩尔％至3.5摩尔％Na2O，9摩尔％至28摩尔％R2O，其中R是碱金属以及R2O至少包括Li2O和Na2O，0摩尔％至10摩尔％Ta2O5，0摩尔％至4摩尔％ZrO2，0摩尔％至4摩尔％TiO2，0摩尔％至3.5摩尔％R'O，R'是选自Ca、Mg、Sr、B