Improvement of Strength and Reliability of Structural Ceramics Through Ion Implantations

该计划的目标是实现实力和 通过离子注入提高结构陶瓷的可靠性 置入 该方法是通过以下步骤产生可沉淀相： 高剂量离子注入和随后退火。 的 局部体积膨胀可使强度增加 由于这些沉淀物的存在， 导致产生压缩表面应力。 如果 形成结晶稳定的沉淀物， 与温度无关强度和可靠性的增加， 预期 如果沉淀相比基体硬， 将导致表面硬化。 在阶段I中，提出共注入硅和碳， 钛和碳转化成氮化硅来研究 形成碳化硅和碳化钛沉淀物。 表征是通过使用透射电子 显微镜 四点弯曲测试提供强度和 可靠性数据

The objective of this program is to achieve strength and reliability improvements in structural ceramics through ion implantation. The approach is to produce precipitable phases by high dose ion implantation and subsequent annealing. The strength increase is expected from the localized volume expansion of the implanted region due to the presence of these precipitates resulting in the generation of compressive surface stresses. If thermodynamically stable precipitates are formed, then a temperature independent increase in strength and reliability is expected. If the precipitate phase is harder than the matrix, a surface hardening should result. In Phase I, it is proposed to co-implant silicon and carbon, and titanium and carbon into silicon nitride to study the formation of silicon carbide and titanium carbide precipitates. Characterization is performed by using transmission electron microscopy. Four-point-bend testing provides strength and reliability data.