化学气相沉积法制备高纯钛工艺研究

Study on preparation of high purity titanium by chemical vapor deposition process

介绍了卤化物热裂解法制备电子级高纯钛的工艺过程。采用单因素实验，研究了反应过程中反应时间、TiI2蒸汽压、卤化区温度以及裂解区温度的影响。同时，结合热力学及动力学分析得到适宜的工艺条件为：反应时间25小时；TiI2蒸汽压3～3．5kPa；卤化区温度550—800℃；沉积区温度为1100—1200℃。在此条件下进行检验性实验，单次高纯钛产量超过3kg。产品经电镜扫描（SEM）观察，晶体横截面断口形貌整齐、规整，结晶情况良好。经电子束炉熔炼后的产品经辉光质谱（GDMS）检测，高纯钛中28种杂质元素总和小于2×10^-3％。

A technology for producing electronic - grade high - purity titanium by thermal decomposition of titanium iodides was introduced. Influences of reaction time, vapor pressure of TiI2, the temperature of source area, the temperature of decomposition area were investigated by single factor experi- ments, at the same time, with thermodynamics and dynamics analysis, optimal process conditions were obtained as follows： reaction time was 25h, the va- por pressure of TiI2 was about 3 -3.5kPa, the temperature of source area was about 550 -800℃ and the temperature of deposition area was 1100 - 1200℃ or so. Under the above conditions, experiment was taken to confirm that the yield exceeded 3kg products were analyzed by SEM. The cross section morphology of crystal fracture is tidy and neat, crystallization in good condition. After electric beam melting, the high purity titanium was obtained and tested by GDMS. The results indicated that the total impurity content of twenty -eight elements was less than 2 × 10-3%.