Effect of energy density on the microstructure and properties of the CrFeCoNiNb high-entropy cladded layer

Pengfang Song,Fulin Jiang,Yuling Wang,Zhaolin Zhong,Fazhan Yang

doi:10.1007/s00170-021-08042-x

Abstract

A synergistic combination of mechanical properties and corrosion resistance property is desired for most ocean engineering structural applications. In this paper, we prepared a high-entropy alloy (HEA) cladded layer of composition CrFeCoNiNb (atomic %). We aim to attain a balance between the mechanical property and the corrosion resistance property by adjusting the energy density. The prepared CrFeCoNiNb cladded layer with an energy density of 116.7 J/mm2 exhibited excellent mechanical properties and high corrosion resistance. The improved mechanical properties are attributed to fine grain strengthening, solid solution strengthening, and dispersion strengthening. Whereas, the excellent corrosion resistance is due to the formation of Laves corrosion-resistant phase structure and the compact passivation film. The variation of the mechanical properties and corrosion resistance with different energy densities are attributed to the phase composition. The proportion of the Laves phase decreases first and then increases with the increase of energy density, which is the main reason that the microhardness of the cladded layer follows a similar trend. The outcome of our research suggests that the prepared CrFeCoNiNb cladded layer could be explored to realize surface strengthening of load-bearing parts in marine engineering equipment.

Highlights

Alloying is a common way of imbuing materials with desirable properties.Traditional alloys are prepared in a way of adding a minor element to the main element
4.1 Phase composition The XRD patterns of CrFeCoNiNb cladded layers at different energy densities are shown in Fig. 5, and the main diffraction peaks are all BCC solid solution
It is found that BCC solid solution[20]is beneficial to improve the hardness of cladded layer

Summary

Introduction

Alloying is a common way of imbuing materials with desirable properties. Traditional alloys are prepared in a way of adding a minor element to the main element. The HEA is composed of four or more elements with approximately equal molar ratio, and its configuration entropy is required to be greater than 1.5R[1]. The final structure of HEA is not dominated by any one element. Due to its high entropy effect, lattice distortion effect, cocktail effect and hysteretic diffusion effect, the HEA has many advantages that traditional alloy cannot reach. The synergistic improvement of strength, toughness and corrosion resistance of the HEA is difficult to achieve, and there is no satisfactory solution so far

Objectives

Results

Conclusion