Processing Ti3Al–SiC nanocomposites using high energy mechanical milling

Ti3Al–10 vol.% SiC and Ti3Al–20 vol.% SiC composite powders were produced by high energy mechanical milling of Ti, Al and SiC powders, using both coarse and fine SiC powders. For a coarse SiC powder, the milling energy has to be high enough to fracture the SiC particles in-situ. While for a fine SiC powder, a lower energy mill is sufficient to produce a nanocomposite powder. Additionally, nanocrystalline Ti(Al) solution was formed during milling. A simple theoretical analysis shows that there exists a lower limit of the particle size below which further reduction of the particle size cannot be achieved by milling since the stresses required for further particle refinement cannot be reached during milling. During consolidation of the Ti3Al–SiC nanocomposite powders, the reaction between the Ti3Al matrix and SiC is difficult to be avoided.