Numerical and experimental abrasive wear study of titanium alloy and MAO coating

Abstract

Solid particle erosion (SPE) behaviour of materials applied in different industries, including a widespread titanium Ti6Al4V alloy remains a subject to study. At the same time, resistance of microarc coatings, well known for their anti-corrosion properties, to erosive wear is yet understudied. Here, in order to estimate the wear resistance behavior and its character, experimental and numerical studies of Ti6Al4V alloy and aluminium-based MAO coating erosion by solid Al 2 O 3 particles (~30 m/sec) have been carried out. The experiment resulted in intensive wear of the MAO coating, which cuts its scope to short-term or indirect anti-erosion protection. Reynolds-averaged Navier – Stokes simulations of heterogenous abrasive-air mixture showed high influence of particle initial velocities and shape on the resulting impact velocity, while good agreement with the experiment was observed. Finite element explicit simulations of the impact, resulting in the deformation and the fracture of the particle and the surface were conducted using the Johnson – Cook model for titanium alloy and the Johnson – Holmquist model for the brittle particle. High influence of the particle orientation and the choice of the material model coefficients for both the particle and the sample was observed. Also, a satisfactory agreement with the experimental surface wear area was noted. Additionally, significant dependence of wear depth on the damage and fracture coefficient in the Johnson – Holmquist model for the Al 2 O 3 brittle particle and surface scenario has been found. Future studies should be addressed to a more detailed survey of the particle rotation, relative angle and position of the impact. Also, additional sensitivity studies are needed to determine the effect of brittle material model coefficients for solid particle erosion simulation cases.