In situ preparation of micro-nano tantalum carbide ceramic
In situ preparation of micro-nano tantalum carbide ceramic
复制标题
原位制备微纳米碳化钽陶瓷
DOI：
10.1007/s11837-020-04177-6
复制
发表时间：
2020
期刊：
影响因子：
2.6
通讯作者：
Xu Yunhua
中科院分区：
文献类型：
--
作者：
Shang Zhao;Bai Haiqiang;Zhong Lisheng;Zhang Qianwei;Xu Yunhua
研究了原位铸造-热处理反应和化学萃取法制备的微纳TaC碳化物的显微组织和力学性能，以及形成和形态演变机制。TAC颗粒的大小约为50-900 nm。其形成过程和机制包括TaC颗粒的形核长大和扩散型固相转变。由于微观结构的“冻结”，抑制了晶界的运动，形成了超细的TaC陶瓷颗粒。表面总自由能最小的TaC颗粒优先生长为被{100}面包裹的立方体，这表明本征晶格结构和生长条件共同决定了TaC颗粒的最终形态。另外，制备的TaC陶瓷的硬度为26.5 ± 0.4GPa，弹性模数为506.4 ± 5.8GPa.断裂韧性为3.8 ± 0.1m1/2，其增韧机制包括裂纹偏转和裂纹桥联。
The microstructure and mechanical properties as well as the formation and morphological evolution mechanism of micro–nano TaC carbide prepared by an in situ casting–heat treatment reaction and chemical extraction method have been investigated. The size of the TaC particles was approximately 50–900 nm. The formation process and mechanism included nucleation growth of TaC grains and a diffusion-type solid-phase transition. Due to the “freezing” of the microstructure, the movement of the grain boundaries is inhibited, resulting in ultrafine TaC ceramic particles. The TaC particles preferably grow as cubes enclosed by {100} facets with minimized total surface free energy, indicating that both the intrinsic lattice structure and the growth conditions determine the final morphology of the TaC particles. In addition, the hardness and elastic modulus of the TaC ceramic were found to be 26.5 ± 0.4 GPa and 506.4 ± 5.8 GPa, respectively. Moreover, the fracture toughness was found to be 3.8 ± 0.1 MPa m1/2. The toughening mechanism of the TaC ceramic layer includes crack deflection and crack bridging.