冷却方式对尖晶石型红外辐射陶瓷结晶的影响

在红外陶瓷制备过程中,不同的冷却方式对红外陶瓷的结晶有一定的影响,进而影响到陶瓷的红外辐射率。采用XRD法研究了Fe、Mn、Co、Cu、Ni尖晶石型红外辐射陶瓷在制备过程中的冷却方式对尖晶石结晶的影响。含锰的尖晶石根据含锰量的高低可采用水中淬冷或在空气中急冷的方式,不能采用自然冷却的方式;高锰含量的配方必须采用水中淬冷的冷却方式;锰含量较低时,可采用空气中急冷的方式。为保证尖晶石晶体的结晶良好,镍尖晶石用在空气中冷却的方式最好。本实验采用的3种冷却方式对钴尖晶石都不太适用,使降温速率比自然冷却稍快些,但比空气中急冷稍慢些,可望有更好的效果。铜尖晶石可采用空气中急冷的方式,既能保证尖晶石的充分结晶,又能使反型铜尖晶石结构变为混合型结构,有利于红外辐射率的提高。

Effects of Cooling Ways on the Crystallization of Spinel Infrared Ceramics

The cooling ways have a certain effects on the crystallization of the spinel infrared ceramics during the sintering,and furthermore,the infrared emissivity of the ceramics is affected.The goal of the investigation is to experimentally demonstrate the effects of the cooling ways on the crystallization of the Fe、Mn、Co、Cu、Ni spinel ceramics.The cooling ways of spinel ceramics containing Mn are water quenching or air quenching in terms of the contents of Mn,natural cooling is not recommended;The water quenching must be used when the contents of Mn is high and the air quenching is accepted when the sample contains little Mn.The best cooling way of the Ni spinel is air quenching in order to get more well-crystallined spinel.The water quenching,air quenching and natural cooling are all not suitable to Co spinel,if the cooling rate of the Co spinel is faster than natural cooling and slower than air quenching,perhaps a better result can be got.The air quenching is adopted to ensure the Cu spinel crystalline well,and furthermore,the inverse Cu spinel structure can turn into mixed one,and the infrared emissivity of the ceramics can be improved.