Abstract The mechanical properties of newly synthesized Ca2C3 and Ca2C under pressure have been studied by using the first-principles calculations with generalized gradient approximation. The equilibrium geometry, elastic stiffness constants, various moduli, and Pugh's ratio of the C2/m phase of Ca2C3 and the C2/m and Pnma phases of CaC2 are systematically studied. The elastic stiffness constants of C2/m-Ca2C3 under 0–30GPa, C2/m-Ca2C under 0–7.5 GPa, and Pnma-Ca2C under 7.5–30 GPa satisfy the Born−Huang mechanical criteria. The three phases of calcium carbides exhibit ductile characteristics. The surface constructions of bulk and Young's moduli illustrate the mechanical anisotropy of Ca2C3 and Ca2C. Our results are consistent with previously obtained experimental and theoretical data and have significant implications for the application of calcium carbides.

中文翻译：

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碳化钙的压力相关机械性能

摘要 利用广义梯度近似的第一性原理计算，研究了新合成的Ca2C3 和Ca2C 在压力下的力学性能。系统地研究了Ca2C3 的C2/m 相和CaC2 的C2/m 和Pnma 相的平衡几何形状、弹性刚度常数、各种模量和Pugh 比。C2/m-Ca2C3 在 0-30GPa 下、C2/m-Ca2C 在 0-7.5 GPa 下和 Pnma-Ca2C 在 7.5-30 GPa 下的弹性刚度常数满足 Born-Huang 力学标准。碳化钙的三相表现出延展性。块体和杨氏模量的表面结构说明了 Ca2C3 和 Ca2C 的机械各向异性。