Abstract: To solve the problem related with short fiber preform preparation such as long preparing time, binder segregation and dimensional instability when removed from the mold, a new preform preparation technique was proposed. The method was characterized in short preparation time by using vacuum and pressure. MgCl₂·MgF₂ was selected as an effective binder. A series of alumina preforms with different fiber volume fraction of 10%, 15%, 20% and 25% were successfully fabricated. Processing conditions for the preform preparation were as follows: the preform was dried for 2 hours at 45 °C, and then gradually heated to 1 100 °C within 1.5 hours. The prepared preform had excellent surface quality, good core strength, and uniform pore and fiber distribution without  fiber loss. Compression tests showed that the alumina preforms met the requirements of infiltration experiments for fabricating composites.

Key words: Al₂O_3sf preform, binder, composite