State Key Laboratory of Powder Metallurgy, Central South University, Changsha, Hunan 410083, China.
J Mech Behav Biomed Mater. 2012 Apr;8:154-64. doi: 10.1016/j.jmbbm.2011.12.001. Epub 2011 Dec 13.
First principle calculations reveal that Mg-Ca phases are energetically favorable with negative heats of formation within the entire composition range, and that a strong chemical bonding is formed between Mg and Ca atoms. Calculations also show that the composition has an important effect on mechanical properties of Mg-Ca, and that the Mg-Ca phases with an Mg composition of less than 50 at.% would be good candidates as degradable bone materials in terms of Young's modulus and ductility. In addition, it is found out that Mg(3)Ca, MgCa and MgCa(3) have phase sequences of BCC→HCP, BCC→HCP and FCC→HCP under high pressure, respectively, and that Ca plays a dominant role in determining the electronic structures and stable crystal structures of various Mg-Ca phases.
第一性原理计算表明，在整个组成范围内，Mg-Ca 相具有能量优势，形成负的形成焓，并且 Mg 和 Ca 原子之间形成强化学键。计算还表明，组成对 Mg-Ca 的力学性能有重要影响，Mg 成分小于 50at.%的 Mg-Ca 相在杨氏模量和延展性方面将是可降解骨材料的候选材料。此外，还发现 Mg(3)Ca、MgCa 和 MgCa(3)在高压下分别具有 BCC→HCP、BCC→HCP 和 FCC→HCP 的相序列，并且 Ca 在确定各种 Mg-Ca 相的电子结构和稳定晶体结构方面起主导作用。
