Plasma Melting of Selected Compositions in the A1₂O₃-ZrO₂-SiO₂ System

Abstract

The application of plasma spraying for coating substrates with refractory materials is a well established discipline.^1,2 The use of a plasma to prepare non-crystalline solids from refractory compositions, however, has received far less attention.^3,4 There are many reasons why plasma melting is attractive for the preparation of noncrystalline solids. Among these are high melting temperatures (> 5,000°K), availability of strong oxidizing or reducing conditions, the attainment of high quench rates for single particles (> 10⁶ °C/s), the maintenance of high purity (for RF plasma torches) and its potential for inducing gas-phase reactions, e.g., vapor phase oxidation of chloride solutions. These potential benefits offer the possibility of preparing refractory glasses of unusual compositions. It was for this reason primarily that the present work was undertaken.