Generalized stacking fault energies of alloys
Generalized stacking fault energies of alloys
复制标题
合金的广义堆垛层错能
DOI：
10.1088/0953-8984/26/26/265005
复制
发表时间：
2014-07-02
影响因子：
2.7
通讯作者：
Vitos, Levente
中科院分区：
文献类型：
--
作者：
Li, Wei;Lu, Song;Vitos, Levente
广义层错能（伽马面）为理解塑性变形机制提供了基础物理。采用从头算精确muffin-tin轨道方法，结合相干势近似，计算了。对无序的Cu-Al、Cu-Zn、Cu-Ga、Cu-Ni、Pd-Ag和Pd-Au合金表面进行了研究。研究了溶质偏聚对层错面的影响，结果表明，只有局部化学成分对层错面的偏聚有影响。面利用基体合金和畸变合金的电子能带结构讨论了计算的合金化趋势。表面的结果，我们证明了先前揭示的“普遍标度律”的内在能量障碍（IEBs）是服从随机固溶体。这大大简化了孪晶测量参数或临界孪晶应力的计算。采用IEBs的两个孪生率度量参数，发现在二元Cu合金中，Al、Zn和Ga使孪生率增加，而Ni使孪生率降低，Al和Ga对孪生率的影响相似。
The generalized stacking fault energy (gamma surface) provides fundamental physics for understanding the plastic deformation mechanisms. Using the ab initio exact muffin-tin orbitals method in combination with the coherent potential approximation, we calculate the. surface for the disordered Cu-Al, Cu-Zn, Cu-Ga, Cu-Ni, Pd-Ag and Pd-Au alloys. Studying the effect of segregation of the solute to the stacking fault planes shows that only the local chemical composition affects the. surface. The calculated alloying trends are discussed using the electronic band structure of the base and distorted alloys.Based on our. surface results, we demonstrate that the previous revealed 'universal scaling law' between the intrinsic energy barriers (IEBs) is well obeyed in random solid solutions. This greatly simplifies the calculations of the twinning measure parameters or the critical twinning stress. Adopting two twinnability measure parameters derived from the IEBs, we find that in binary Cu alloys, Al, Zn and Ga increase the twinnability, while Ni decreases it. Aluminum and gallium yield similar effects on the twinnability.