Effect of ball-milling granulation with PVB adhesive on the sinterability of co-precipitated Yb:YAG nanopowders

Ball-milling granulation parameters with polyvinyl butyral (PVB) adhesive have been optimized for the preparation of granulated Yb:YAG powders, using the co-precipitated raw powders. The influence of the amount of PVB (0–1.5wt%) and ball-milling time (0–20h) on the phase composition, particle size and morphologies of resultant powders is evaluated. The results show that ball milling for 10h breaks the sintering neck of the particles while 0.5wt% PVB adhesive contributes to ball-milling granulation and boosts the dispersion of granulated powders. It is found that when ball-milled with 0.5wt% PVB for 10h, the powders show high sintering activity. Using these granulated nanopowders, nearly full dense Yb:YAG ceramic with 99.6% of theoretical density was obtained by vacuum sintering at 1750°C for 15h. The optical transmittance of Yb:YAG ceramic reaches up to 80% in the visible light region and 82% at 1030nm. The sample exhibit pore-free structures and the average grain size is about 9μm. Experimental evidence proved that ball-milling granulation with PVB adhesive could be an effective and facile method to improve sinterability of nanopowders.