Microstructure and Oxidation Behavior of Boron-Added WSi<SUB>2</SUB> Compact

Abstract

In order to improve the oxidation resistance of WSi 2 at 873-1473 K, B added WSi 2 was fabricated by a spark plasma sintering method and oxidation tests were carried out in air. The fabricated B added WSi 2 consists of WSi 2 , Si and W 2 B 5 . The addition of B into WSi 2 leads to the formation of a protective borosilicate scale, resulting in improvement of the oxidation resistance. Requisite concentration of B for the formation of a protective borosilicate scale decreases as the temperature is raised. Consequently, the addition of 2 or 3 mass% B is the most effective for improvement of the oxidation resistance of WSi 2 in the temperature range of 873-1473 K. Such effect of B on high-temperature oxidation of WSi 2 is also discussed.