Sintering abnormal grain growth

Another additive that has been investigated to improve the performance of HA is Hthium (Li). The addition of lithium can increase the microhardness and produces a fine microstructure in HA. Fanovich et al. [1998] found that the addition of 0.2 wt% of Li to HA produced the maximum microhardness (5.9 GPa). However, the addition of high amounts of Li to HA results in abnormal grain growth and large pores. Furthermore, Li addition to HA results in the formation of /3-TCP upon sintering. 

Figure 9.3. Abnormal grain growth of alumina in the presence of a liquid phase." AI2O3 powder compact ( 0.05 wt% anorthite) sintered at I580°C for 12h in air. (Reprinted with permission of the American Ceramic Society, www.ceramics.org.)...

Xue, L. A., Thermodynamic benefit of abnormal grain growth in pore elimination during sintering, J. Am. Ceram. Soc., 72, 1536 37, 1989. 

Si,B Sintering aids To lowering sintering temperature To suppress abnormal grain growth... 

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