Diamond, cubic boron nitride (c-BN), silicon (Si), and germanium (Ge), as examples of typical strong covalent materials, have been extensively investigated in recent decades, owing to their fundamental importance in material science and industry. However, an in-depth analysis of the character of these materials' mechanical behaviors under harsh service environments, such as high pressure, has yet to be conducted. Based on several mechanical criteria, the effect of pressure on the mechanical properties of these materials is comprehensively investigated. It is demonstrated that, with respect to their intrinsic brittleness/ductile nature, all these materials exhibit ubiquitous pressure-enhanced ductility. By analyzing the strength variation under uniform deformation, together with the corresponding electronic structures, we reveal for the first time that the pressure-induced mechanical softening/weakening exhibits distinct characteristics between diamond and c-BN, owing to the differences in their abnormal charge-depletion evolution under applied strain, whereas a monotonous weakening phenomenon is observed in Si and Ge. Further investigation into dislocation-mediated plastic resistance indicates that the pressure-induced shuffle-set plane softening in diamond (c-BN), and weakening in Si (Ge), can be attributed to the reduction of antibonding states below the Fermi level, and an enhanced metallization, corresponding to the weakening of the bonds around the slipped plane with increasing pressure, respectively. These findings not only reveal the physical mechanism of pressure-induced softening/weakening in covalent materials, but also highlights the necessity of exploring strain-tunable electronic structures to emphasize the mechanical response in such covalent materials.

金刚石、立方氮化硼 (c-BN)、硅 (Si) 和锗 (Ge) 作为典型的强共价材料的例子，由于它们在材料科学和工业中的根本重要性，近几十年来得到了广泛的研究。然而，尚未对这些材料在高压等恶劣服务环境下的机械行为特征进行深入分析。基于几个力学标准，全面研究了压力对这些材料力学性能的影响。结果表明，就其固有的脆性/延展性而言，所有这些材料都表现出普遍存在的压力增强延展性。通过分析均匀变形下的强度变化，以及相应的电子结构，我们首次揭示了压力诱导的机械软化/弱化在金刚石和 c-BN 之间表现出明显的特征，这是由于它们在施加应变下的异常电荷耗尽演化存在差异，而在 Si 和 c-BN 中观察到单调的弱化现象。葛。对位错介导的塑性阻力的进一步研究表明，金刚石 (c-BN) 中的压力诱导的混洗凝固面软化和 Si (Ge) 中的弱化可归因于费米能级以下反键态的减少，以及增强的金属化，分别对应于滑动平面周围的键随着压力的增加而减弱。这些发现不仅揭示了共价材料中压力诱导软化/弱化的物理机制，