Measurement of thermal expansion of Li2TiO3 pebble beds

Thermal expansion behavior of a packed bed is studied for Li2TiO3 pebbles. Under a compressive load of 0.1 MPa, the thermal expansion of the bed was measured. The average thermal expansion coefficient was estimated in the temperature range from room temperature to about 973 K. For the beds with different packing factors from 65.3 to 68.5%, the thermal expansion coefficients were (1.4 ± 0.2) × 10−5 K−1. It was found that a residual deformation in the bed cased by a preloading could be annealed when the bed is heated without the load. The thermal expansion behavior of the beds is explained by taking into account the progress of compression and its relaxation.