Mechanical Properties and Deformation of Polycrystalline Lithium Orthosilicate

摘要

Room-temperature strength, fracture toughness, Young's modulus, and thermal-shock resistance were determined for 68--98% dense lithium orthosilicate (Li sub 4 SiO sub 4 ) specimens. In the low-density regime, both strength and fracture toughness were controlled by the density of the specimen. At high density, the strength depends on grain size. Young's modulus values ranged from 30--103 GPa at densities between 68 and 98% TD. A critical quenching temperature difference in the range of 150--170/degree/C was observed in thermal-shock tests of bar specimens. Steady-state creep tests indicated 90% dense Li sub 4 SiO sub 4 fractures at T less than or equal to 800/degree/C before reaching steady state and deforms plastically at 900/degree/C. It is more creep-resistant at 900/degree/C than Li sub 2 O, about equal to Li sub 2 Zr) sub 3 , and less than LiA10 sub 2 . 13 refs., 4 figs., 1 tab. (ERA citation 13:036926)