Synthesis and thermal expansion hysteresis of Ca1â€�?�ð�?�¥Sr𝑥Zr4P6O24

[摘要] The low thermal expansion ceramic system, Ca_{1-ð‘�?}Sr_ð‘�?Zr₄P₆O₂₄, for the compositions with ð‘�? = 0, 0.25, 0.50, 0.75 and 1 was synthesized by solid-state reaction. The sintering characteristics were ascertained by bulk density measurements. The fracture surface microstructure examined by scanning electron microscopy showed the average grain size of 2.47 ^ðœ�?m for all the compositions. The thermal expansion data for these ceramic systems over the temperature range 25â€�??800°C is reported. The sinterability of various solid solutions and the hysteresis in dilatometric behaviour are shown to be related to the crystallographic thermal expansion anisotropy. A steady increase in the amount of porosity and critical grain size with increase in ð‘�? is suggested to explain the observed decrease in the hysteresis.

[学科分类] 材料工程

[关键词] Low-thermal expansion;thermal expansion hysteresis;NZP ceramics.