Erich Schmid Institute of Materials Science, Austrian Academy of Sciences, Jahnstrasse 12, A-8700 Leoben, Austria.
Phys Rev Lett. 2010 May 14;104(19):195503. doi: 10.1103/PhysRevLett.104.195503. Epub 2010 May 13.
Despite exhibiting the highest melting point of all metals, the technological use of tungsten is hampered by its room-temperature brittleness. Alloying with Re significantly ductilizes the material which has been assigned to modified properties of the 1/2(111) screw dislocation. Using density functional theory, we show that alloying induces a transition from a symmetric to an asymmetric core and a reduction in Peierls stress. This combination ductilizes the alloy as the number of available slip planes is increased and the critical stress needed to start plastic deformation is lowered.
尽管钨具有所有金属中最高的熔点，但由于其在室温下的脆性，其在技术上的应用受到了阻碍。与 Re 合金化可显著提高材料的延展性，这归因于 1/2(111)位错的修正特性。本研究使用密度泛函理论表明，合金化会引起从对称到不对称核心的转变，并降低派尔斯应力。这种组合通过增加可用的滑移面数量和降低开始塑性变形所需的临界应力使合金变得具有延展性。
