钛酸铝陶瓷材料在铝熔体中的抗热震行为及热膨胀特性的研究

Study on the Behavior of Thermal Shock Resistance and Thermal Expansion of Aluminum Titanate Ceramics in Aluminum-Melt

钛酸铝陶瓷材料具有低膨胀、抗热震和与有色金属熔体不润湿等特性,是制备铝合金低压铸造机用易损件升液管、中间管,以及铝熔体熔炉内腔的首选材料。作者模拟升液管的应用条件,将钛酸铝陶瓷试块浸润到铝熔体中(750℃),周期性间隔1h取出,测试其室温抗弯强度和热膨胀性能的变化,研究了钛酸铝陶瓷材料的抗热震性能。发现钛酸铝陶瓷经历最初的热震时,强度变化较大,但抗弯强度仍保持在30MPa左右,经历10次浸润和热震后,强度基本恒定,约为初始抗弯强度(36MPa)的80%,抗热震性能优良,可以适应铝合金低压铸造的间歇应用。

Aluminum titanate ceramics,which takes on low thermal expansion, high thermal shock resistance and nonwettability with nonferrous metalsmelt, is a first line materials for the preparations of the pipe for feeding aluminummelt and middle pipe used in lowpressure die casting as well as the firebrick used in the lumen of the melting furnace of aluminummelt. In this paper, the thermal shock resistance of aluminum ceramic materials was investigated by testing the flexural strength and thermal expansion behavior of the aluminum titanate ceramics which was soaked in aluminum melt (750℃) and periodically took out at intervals of 1 hour. The results showed that in the initial period of thermal shock the flexural strength of aluminum titanate ceramics decreases acutely, but still remains about 30MPa, and after suffered 10 times thermal shock the flexural strength do not decrease much more and maintains about the initial strength (36MPa) of 80%. The aluminum titante ceramics has excellent thermal shock resistance and can be used in fitful aluminum alloy lowpressure diecasting.