Liquid–Solid Impact Mechanism, Liquid Impingement Erosion, and Erosion-Resistant Surface Engineering: A Review

Abstract

Liquid impingement erosion has been known as mechanical degradation, where the original material is removed progressively from a solid surface due to continued exposure to impacts by high-speed liquid droplets. This is a major issue in many industries, including aerospace and aviation and power generation, particularly gas and steam turbines, nuclear power plants, and wind energy. Tremendous numerical and experimental studies have been performed so far to understand the physical phenomena involved in this process and to improve the erosion resistance of different surfaces. In this review paper, first, the liquid–solid impact in a wide range of relative velocities is reviewed fundamentally. Then, the liquid impingement erosion of metals, including damage regimes and damage accumulation mechanisms, as well as the role of solid properties on erosion performance are explained. Finally, promising water droplet erosion-resistant materials and surface treatments are discussed. This review paper is intended to summarize the present knowledge of the different mechanisms involved in the liquid impingement erosion process.

Hybrid Smoothed-Particle Hydrodynamics/Finite Element Method Simulation of Water Droplet Erosion on Ductile Metallic Targets

“…This is due to the strong non-linear dynamics of the erosion process and the complex mechanisms that emerge when impact velocity and angle are varied. 3 versus the accumulated number of water droplet impacts for impact velocity 𝑣 = 1000 m/s at different impact angles. The variable "eir" (from "end of incubation regime") is approximately the number of impacts required for erosion for each impact angle.…”

“…There is an important detail to be considered in Figure 5a,b: The simulation for an impact angle of 90° stopped shortly after 900 impacts due to numerical instability. There- 3 versus the accumulated number of water droplet impacts for impact velocity 𝑣 = 800 m/s at different impact angles. The variable "eir" (from "end of incubation regime") is approximately the number of impacts required for erosion for each impact angle.…”

“…The repeated impact of high-velocity water droplets on metallic surfaces produces an accumulation of surface and bulk damage that eventually evolves into erosion [1][2][3]. Water droplet erosion is a serious problem in low-pressure steam turbines [4][5][6], aeroengine fan blades [7], and wind turbine blades [8][9][10].…”

“…In the initial stage of water droplet erosion (WDE), there is an incubation period with negligible mass loss whose duration is strongly dependent on water droplet size and velocity distributions, the initial state of the target surface, and material properties of the target [13][14][15]. Material properties like yield, tensile, and fracture strength affect the ability of materials to resist erosion [3,16]. Hardness is directly related to the surface resistance to plastic deformation and definitively is a main factor for determining the erosion resistance of specific material alloys [1,17].…”

“…Clearly, there is 2 of 13 not an intrinsic mechanical property that individually accounts for water droplet erosion and most of the experimental studies consider a combination of a number of mechanical properties [17]. From the point of view of industrial applications, the prediction of the incubation period duration and formulation of strategies for its extension is one of the main topics of research [3].…”