The Phase-Formation Behavior of Composite Ceramic Powders Synthesized by Utilizing Rice Husk Ash from the Biomass Cogeneration Plant

Figure 4

SEM images of sample R3 after calcination at different temperatures for 3 h: (a) 1773 K, (b) 1803 K, (c) 1823 K, and (d) 1853 K.

(a)

(b)

(c)

(d)