软析出相的强化机理

This research work provided a recipitation hardening mechanism in materials ontaining soft precipitates. The proposed strengthening mechanism was successfully applied in Ni3Al intermetallic compound in which solid solution Ni phase was finally distributed and explained successfully the experiment results. The research result shows that the soft precipitates are effective not only in increasing the strength of the matrix but also in enhancing the plastic deformation ability of the matrix. hen the solid solution Ni phase was precipitated finally in Ni3(Al,Ti), the high-temperature strength was increased dramentically and the temperature in which the tensil strength of the matrix exhibited maximum increased at about 200 degrees. The experimental results show that the precipitations of a-Co in Co3Ti, a-Fe and a-Cr in NiAl also increased the strength of the matrix. These results mentioned above show that soft precipitates in harder matrix can increase not only the room temperature strength but also the high temperature strength. This type of mechanism is a new method for designing the materials, especially the high temperature materials.

建立当超位错与析出相之间存在引力型相互作用条件下的析出强化机理。通过时效强化，强度测定运动位错与析出相的电镜观察，对所建立的理论模型加以实验验证。本研究的完成不仅对材料科学的基础理论而且在材料设计理论上特别是高温材料的设计思路上具有重要参考意义。