Method for treating a contact surface for a mullite-based refractory recipient, and a coating made with this method

摘要

The invention proposes a method for passivating the contact surface of a refractory container made of mullite. Such a method is remarkable in that it comprises the following operations: a. application to the contact surface of a coating comprising 50% to 70% by weight of alumina flour (Al₂O₃) filler and 30% to 50% of binder, this binder itself comprising 50% to 60% of aluminum chloride AlCl₃ dissolved in 40% to 50% of water; b. drying; c. firing of the container in an oxidizing atmosphere between 1450° C. and 1550° C. for at least 20 min. Application to the casting of titanium alloys.