| 摘要 |
<p>PROBLEM TO BE SOLVED: To improve transparency and to effectively perform production by specifying a composition of Al2 O3 and SiO2 and specifying the average particle diameter range. SOLUTION: The amorphous mullite based fine particle has a composition of 50-80 wt.% Al2 O3 and 20-50 wt.% SiO2 and is 10-70 nm in the average particle diameter and produced as follows. An Al -Si alloy long body consisting of about 75 mol.% Al and about 25 mol.% Si is mounted in a device and is used as a consumable anode, a torch having a cathode arranged at the center is provided at an opposite position facing the tip of the alloy long body, the cathode is protected from an oxidizing atmosphere by gaseous argon supplied into the torch and voltage is impressed between the electrodes to arc discharge. As a result, the plasma flame of gaseous argon is generated to heat and vaporize the alloy and the vapor is oxidized and cooled to obtain the mullite based fine particle having a required composition and particle diameter.</p> |
