Microwave Sintering of Partially Stabilized Zirconia Using a Domestic Microwave Oven

采用微波加热法对部分稳定氧化锆（PSZ）粉体进行了致密化处理。将PSZ粉末压坯夹在两块ZnO-MnO_2-Al_2O_3（ZMA）陶瓷板之间，作为微波炉的预热器，放入微波炉中。用国产微波炉烧结16 min，制得的PSZ陶瓷的密度为5.94 g/cm^3，与常规炉法1350 ℃烧结4 h或1400 ℃烧结16 min的密度相当。经ZMA陶瓷预加热的PSZ颗粒更容易吸收微波能量并自加热到更高的温度。微波加热不仅促进了致密化，而且促进了晶粒长大。从这一点来看，微波的照射可以促进原子的扩散，微波烧结的试样的抗弯强度与传统烧结（1450 ℃，4 h）的试样相当。从这一点来看，采用家用微波炉烧结的方法比传统的方法能耗低、成本低，可以认为是一种较好的烧结方法。在家用微波炉中加热11分钟，得到致密的试样。烧结碳化硅用作预热器。

Partially stabilized zirconia (PSZ) powders were fully densified by microwave heating using a domestic microwave oven. The pressed powder compacts of PSZ were sandwiched between two ZnO-MnO_2-Al_2O_3 (ZMA) ceramic plates acting as preheaters in the microwave oven and put in the oven. PSZ ceramics fabricated with the domestic microwave oven for 16 min exhibited a density of 5.94 g/cm^3, which is approximately equal to the density of bodies sintered at 1350 ℃ for 4 h or at 1400 ℃ for 16 min by the conventional furnace method. The PSZ pellet pre-heated by the ZMA ceramics more easily absorbed the microwave energy and self-heated to a higher temperature. The microwave heating enhanced not only the densification but also the grain growth. From this viewpoint, it was judged that the atomic diffusion should be promoted by irradiation of the microwave.The bending strength of specimens sintered by microwave heating was comparable with that sintered by a conventional method (1450 ℃, 4 h). From this viewpoint, it is judged that this sintering method using an domestic microwave oven is better than the conventional method for the low energy consumption and low cost.The similar method was applied on the sintering of lead zirconate titanate (PZT). The dense specimens were obtained for 11 min of driving a domestic microwave oven. Sintered silicon carbide was used as a preheater.