2024-04-29 パデュー大学
＜関連情報＞
- https://www.purdue.edu/newsroom/releases/2024/Q2/purdue-researchers-improve-the-plasticity-of-ceramic-materials-at-room-temperature.html
- https://www.science.org/doi/10.1126/sciadv.adj4079?_ga=2.163780735.1911246307.1714441198-1085351435.1681791653
- https://www.nature.com/articles/s41467-018-04333-2
高温予荷重により脆性セラミックスの室温塑性を実現 Achieving room temperature plasticity in brittle ceramics through elevated temperature preloading
CHAO SHEN, JIN LI, TONGJUN NIU, JAEHUN CHO, […], AND XINGHANG ZHANG
Science Advances Published:17 Apr 2024
DOI:https://doi.org/10.1126/sciadv.adj4079
Abstract
Ceramic materials with high strength and chemical inertness are widely used as engineering materials. However, the brittle nature limits their applications as fracture occurs before the onset of plastic yielding. There has been limited success despite extensive efforts to enhance the deformability of ceramics. Here we report a method for enhancing the room temperature plastic deformability of ceramics by artificially introducing abundant defects into the materials via preloading at elevated temperatures. After the preloading treatment, single crystal (SC) TiO2 exhibited a substantial increase in deformability, achieving 10% strain at room temperature. SC α-Al2O3 also showed plastic deformability, 6 to 7.5% strain, by using the preloading strategy. These preinjected defects enabled the plastic deformation process of the ceramics at room temperature. These findings suggest a great potential for defect engineering in achieving plasticity in ceramics at room temperature.
その場圧縮による延性フラッシュ焼結セラミックスの高温変形性 High temperature deformability of ductile flash-sintered ceramics via in-situ compression
Jaehun Cho,Qiang Li,Han Wang,Zhe Fan,Jin Li,Sichuang Xue,K. S. N. Vikrant,Haiyan Wang,Troy B. Holland,Amiya K. Mukherjee,R. Edwin García & Xinghang Zhang
Nature Communications Published:25 May 2018
DOI:https://doi.org/10.1038/s41467-018-04333-2
Abstract
Flash sintering has attracted significant attention as its remarkably rapid densification process at low sintering furnace temperature leads to the retention of fine grains and enhanced dielectric properties. However, high-temperature mechanical behaviors of flash-sintered ceramics remain poorly understood. Here, we present high-temperature (up to 600 °C) in situ compression studies on flash-sintered yttria-stabilized zirconia (YSZ). Below 400 °C, the YSZ exhibits high ultimate compressive strength exceeding 3.5 GPa and high inelastic strain (~8%) due primarily to phase transformation toughening. At higher temperatures, crack nucleation and propagation are significantly retarded, and prominent plasticity arises mainly from dislocation activity. The high dislocation density induced in flash-sintered ceramics may have general implications for improving the plasticity of sintered ceramic materials.
