Al和Fe对Cr20Ni80电热合金性能影响的第一性原理研究

First Principle Study on Effects of Al and Fe Doping on Properties of Cr20Ni80 Electrothermal Alloy

采用第一性原理和实验相结合的方法探究了Al和Fe掺杂对Cr20Ni80电热合金弹性性能和电性能的影响。构建了Cr20Ni80超晶胞模型,确定了Al和Fe在超晶胞中的占位,并对模型的准确性进行了验证,计算了体系掺杂前后的形成热、结合能及能带结构,预测了Al和Fe掺杂对合金性能的影响趋势,并采用拉伸试验、X射线衍射以及电阻率测试等方法进行了验证。结果表明,Al和Fe的掺杂没有改变合金的物相,但导致合金的晶格发生了畸变,原子之间电子云的重新分布降低了合金的强度但提高了其塑性;掺杂使合金导带的能量范围变窄,合金的电阻增大。实验结果与第一性原理计算预测结果一致。

Effects of Al and Fe doping on the elastic and electrical properties of Cr20 Ni80 electrothermal alloy were investigated by first principles and experiments. The Cr20 Ni80 supercell model was constructed, and the occupation of Al and Fe in the supercell was determined, while the accuracy of the model was verified. The formation heat, binding energy and band structure of the system before and after doping were calculated. And the influence trend of Al and Fe doping on the properties of the alloy was predicted. The tensile test, X-ray diffraction and resistivity test were used to verify the model. The results show that the doping of Al and Fe does not change the phase of the alloy, but leads to lattice distortion. The redistribution of electron cloud between atoms reduces the strength of the alloy, but improves the plasticity;the doping narrows the energy range of the conduction band and increases the resistance of the alloy. The experimental results are consistent with the predicted results of first principles calculation.