Study On Sand Erosion Resistance Of Titanium Alloy Blade

During military helicopters flight under harsh conditions like deserts, dust and sand in the air can be inhaled into the engine along with high speed airflow, which may cause erosion to compressor blades made of titanium alloy. Normal operation and flight safety of the aero-engine can be significantly affected by the sand erosion result due to material loss and mechanical properties decline of blades. So the research on the effect of blade erosion has a vital significance.In this paper, study on the sand erosion of titanium alloy compressor blades was carried out, three aspects of research are accomplished as follows:(1) Numerical simulation and experimental research are conducted on the single particle erosion of TC4 material(300m/s). In the process of sand impacting titanium alloy plates, the damage caused by polygonal particle is more severe than that of spherical particles; there is residual stress left in the collision area; damage characteristics are different as erosion angle varies.(2) An erosion experimental apparatus is set up to carry out the sand erosion test(100m/s~300m/s). Result shows that erosion rate peaks at 45° and increases with the respect of erosion velocity; surface roughness increases with the erosion speed and peaks at 60°. Investigation into surface microstructure indicates that erosion mechanisms differ with impacting angles. When impacting angle changes from low to high, the erosion mechanisms transition from micro-cutting to platelet.(3) The fatigue strength of the smooth and erosion specimens is tested. Erosion causes the decline of fatigue strength. Micro crack and breach contribute to the reduction of fatigue life. Slender and directional phase is found in the surface layer of the damage zone.