Weidner Anja, Ranglack-Klemm Yvonne, Zienert Tilo, Aneziris Christos G, Biermann Horst
Institute of Materials Engineering, Technische Universität Bergakademie Freiberg, 09599 Freiberg, Germany.
Institute of Ceramic, Glass and Construction Materials, Technische Universität Bergakademie Freiberg, 09599 Freiberg, Germany.
Materials (Basel). 2019 Nov 27;12(23):3927. doi: 10.3390/ma12233927.
The present study provides the mechanical properties of a new generation of refractory composites based on coarse-grained AlO ceramic and the refractory metals Nb and Ta. The materials were manufactured by refractory castable technology and subsequently sintered at 1600 °C for 4 h. The mechanical properties and the damage behavior of the coarse-grained refractory composites were investigated at high temperatures between 1300 and 1500 °C. The compressive strength is given as a function of temperature for materials with two different volume fractions of the refractory metals Ta and Nb. It is demonstrated that these refractory composites do not fail in a completely brittle manner in the studied temperature range. The compressive strength for all materials significantly decreases with increasing temperature. Failure occurred due to the formation of cracks along the ceramic/metal interfaces of the coarse-grained AlO particles. In microstructural observations of sintered specimens, the formation of tantalates, as well as niobium oxides, were observed. The lower compressive strength of coarse-grained Nb-AlO refractory composites compared to Ta-AlO is probably attributed to the formation of niobium oxides. The formation of tantalates, however, seems to have no detrimental effect on compressive strength.
本研究给出了基于粗晶AlO陶瓷以及难熔金属Nb和Ta的新一代耐火复合材料的力学性能。这些材料采用耐火浇注料技术制造，随后在1600℃下烧结4小时。在1300至1500℃的高温下研究了粗晶耐火复合材料的力学性能和损伤行为。给出了具有两种不同体积分数的难熔金属Ta和Nb的材料的抗压强度随温度的变化函数。结果表明，在研究的温度范围内，这些耐火复合材料并非完全以脆性方式失效。所有材料的抗压强度均随温度升高而显著降低。失效是由于沿粗晶AlO颗粒的陶瓷/金属界面形成裂纹所致。在烧结试样的微观结构观察中，观察到钽酸盐以及铌氧化物的形成。与Ta-AlO相比，粗晶Nb-AlO耐火复合材料的抗压强度较低可能归因于铌氧化物的形成。然而，钽酸盐的形成似乎对抗压强度没有不利影响。
