Adding 4% dust as sintering aid in the single silica powder refractory aggregate

it was sintered at 1 400℃ and 1500℃

and BST 401 bending strength tester was used to measure the bending strength of sintered samples.Meanwhile

compared with the single silica powder aggregate

the sintering mechanism of the refractory aggregate contained 4% dust was analyzed.The results show that liquid sintering of the silica powder is promoted with the dust addition

however

absence of effect on the solid sintering can be observed.During the sintering process

liquid sintering exhibits dominant role in the sintering process.The sintered samples were observed by a scanning electron microscope（SEM）.Appropriate amount of liquid phase is generated in the refractory aggregate at 1 500℃

and sintered samples exhibit desirable structure

meeting the requirements of the refractory aggregate in the coating for cast in steel evaporated pattern casting.