Density-functional theory (DFT) based first-principles calculations were used to investigate the crystal structure, binding energy, phase stability and elastic properties of body-centered cubic (BCC) W-based binary solid solutions. The effect of alloying up to 50 atomic percent (at.%) concentration range is determined from the virtual-crystal approximation (VCA) approach. Resulting BCC solid solutions are assessed in comparison to the ideal Vegard's law. Solubility of the alloying elements is characterized by the negative enthalpy of mixing. The values of elastic constants computed for the ground state structures are used to assess the effect of alloying on the ductility and hardness. Based on current results, it seems key to strike a tricky balance between moderate Pugh's modulus ratio (B/G) between bulk and shear moduli (B,G) and elastic anisotropy (A) such that high hardness is not completely compromised at the expense of ductility. The predicted property trends are in agreement with existing theoretical and experimental data, which is indicative that the VCA approach is reliable in development of such alloys.

基于密度泛函理论（DFT）的第一性原理计算用于研究基于体心立方（BCC）W的二元固溶体的晶体结构，结合能，相稳定性和弹性。根据虚拟晶体近似（VCA）方法确定合金化浓度范围达50个原子百分比（at。％）的效果。与理想的维加德定律相比，评估了所得的BCC固溶体。合金元素的溶解度以混合的负焓为特征。为基态结构计算的弹性常数值用于评估合金化对延性和硬度的影响。根据目前的结果，在中等的Pugh模量比（B / G）介于体积模量和剪切模量（B，G）和弹性各向异性（A）之间，因此不会以延展性为代价完全损害高硬度。预测的性能趋势与现有的理论和实验数据一致，这表明VCA方法在开发此类合金方面是可靠的。