铟锡氧化物陶瓷靶材热等静压致密化研究

Investigation on Densification of ITO Ceramic Target by Using HIP Technique

用化学共沉淀法制备了铟锡氧化物（ＩＴＯ）复合粉末。粉末经冷等静压成型后进行热等静压致密化。热等静压时采用碳钢作包套，采用铜箔作隔层。实验研究了热等静压工艺参数──保温温度、保压压力和保温时间对 ＩＴＯ陶瓷靶材致密化的影响。实验结果表明：靶材的相对密度在大约 １０００℃处有一峰值；相对密度随压力增加而增加；当保温温度较低时，适当延长保温时间有利于提高密度；当保温温度较高时，延长保温时间反而使密度降低。分析了 ＩＴＯ在高温下的分解行为以及这种行为对致密化的作用。还分析了 ＩＴＯ复合粉末部分脱氧使ＩＴＯ陶瓷半导化的机理。

ITO complex powders were synthesized by using chemical coprecipitation method. Such powders were densified by using HIP technique, where the carbon steel was used as capsule and Cu foil as separation layer set between capsule and green body compacted using CIP technique. The effect of main parameters of HIP technique on the densification of ITO ceramic target was investigated. The experimental results showed that the relative density had a peak value at the temperature of about 1000℃ and increased with the pressure, and that the relative density increased with time when lower temperature was used, but decreased with time when higher temperature was used. Additionally, the decomposition behavior of ITO at high temperature and its effect on the densification were studied. Why ITO ceramics were semiconducted by removing partial oxygen from ITO complex powders was also explained.