Prediction and Theoretical Investigation of Dehydrogenation Enthalpy of V-Ti-Cr-Fe Alloy Using Machine Learning and Density Function Theory

Abstract

The dehydrogenation enthalpy, a crucial thermodynamic parameter, determines the difficulty of hydrogen desorption in V-Ti-Cr-Fe alloy, but it is unaffordable to predict the dehydrogenation enthalpy and investigate the synergistic effects of structural parameters relying on conventional experimental methods. In this paper, an extreme gradient boosting(Xgboost) model with feature selection is developed, which can obtain a relative error under 15% in prediction on most of the data. Moreover, the genetic algorithm is utilized for optimizing alloy composition having suitable dehydrogenation enthalpy. The accuracy of prediction and optimization is demonstrated by the subsequent experimental validation, where the error between calculation and experiment is within 4.5%. The dehydrogenation process is analyzed using density function theory(DFT) in order to determine the key features provided by machine learning, which suggests that the volumes, valence electrons, and bulk module factors have a significant impact. This research supplies an efficient way of using machine learning to predict and optimize the dehydrogenation enthalpy. In addition, DFT calculation also validates the feature importance outputted by machine learning and reveals the principle of feature effects at the microscopic aspect.

Keywords: dehydrogenation enthalpy, V-Ti-Cr-Fe alloy, machine learning, density function theory