Glassy carbon (GC) is a type of non-graphitizing disordered carbon material at ambient pressure and high temperatures, which has been widely used due to its excellent mechanical properties. Here we report the changes in the microstructure and mechanical properties of GC treated at high pressures (up to 5 GPa) and high temperatures. The formation of intermediate sp²–sp³ phases is identified at moderate treatment temperatures before the complete graphitization of GC, by analyzing synchrotron X-ray diffraction, Raman spectra, and transmission electron microscopy images. The intermediate metastable carbon materials exhibit superior mechanical properties with hardness reaching up to 10 GPa and compressive strength reaching as high as 2.5 GPa, nearly doubling those of raw GC, and improving elasticity and thermal stability. The synthesis pressure used in this study can be achieved in the industry on a commercial scale, enabling the scalable synthesis of this type of strong, hard, and elastic carbon materials.

玻碳（GC）是一种在环境压力和高温下非石墨化的无序碳材料，由于其优异的机械性能而被广泛使用。在这里，我们报告了在高压（高达5 GPa）和高温下处理的GC的微观结构和力学性能的变化。中间sp ² –sp ³的形成通过分析同步加速器X射线衍射，拉曼光谱和透射电子显微镜图像，可以在中等处理温度下，在GC完全石墨化之前确定相。中间亚稳态碳材料具有优异的机械性能，硬度高达10 GPa，压缩强度高达2.5 GPa，几乎是原始GC的两倍，并改善了弹性和热稳定性。这项研究中使用的合成压力可以在工业上以商业规模实现，从而可以实现这种类型的强，硬和弹性碳材料的可扩展合成。