MgO烧结助剂对CaZr4（PO4）6陶瓷力学性能及热膨胀系数的影响

The Effects of MgO Addition on Mechanical Properties and Thermal Expansion Coefficient of CaZr4（PO4）6 Ceramics

用共沉淀法制备了CaZr4(PO4)6陶瓷粉体,并以MgO为烧结助剂,在1200℃~1400℃下烧结制备出CaZr4(PO4)6陶瓷。研究了MgO烧结助剂对CaZr4(PO4)6陶瓷的物相组成、显微结构、力学性能及热膨胀系数的影响。实验结果表明,添加适量的MgO可以促进CaZr4(PO4)6陶瓷的烧结,明显提升其力学性能。尽管MgO的添加会产生少量的第二相Mg3(PO4)2,但该第二相的生成使CaZr4(PO4)6陶瓷的热膨胀系数由负值趋近于零。当MgO的添加量为0.30 wt%时,所制备的CaZr4(PO4)6陶瓷综合性能最好:相对密度为96.5%,热膨胀系数为-1.4×10^-6/℃,抗弯强度为44.2 MPa。

CaZr4(PO4)6(CZP)ceramics were prepared by sintering the CaZr4(PO4)6 powders,synthesized by co-precipitation method,at 1200℃~1400℃ with the addition of MgO.The effect of MgO addition on the phase composition,microstructure,mechanical properties and thermal expansion coefficient of the CZP ceramics were studied.The results indicated that proper addition of MgO can promoted the sintering of CZP and the mechanical properties of the prepared ceramics were improved obviously.MgO addition could lead to the formation of a second phase Mg3(PO4)2,owing to which the thermal expansion coefficient of CZP ceramics was close to zero.The CZP ceramics added with 0.30wt% MgO showed the best properties:the relative density was 96.5%,the thermal expansion coefficient was-1.02×10^-6/℃ and the flexural strength reached 44.2 MPa.