Erosion of in-situ TiC particle reinforced Al–5Cu composite

Erosion behavior of in-situ 15 vol% TiC particle reinforced Al–5Cu based composite and the monolithic Al–5Cu alloy was studied at oblique and normal impacts. The erosion rate of the composite was higher than that of the monolithic alloy. There existed low-angle peaks in erosion rate vs. impact angle curves for the two materials, which indicated ductile erosion behavior although the composite had a low tensile ductility. Theoretical model for ductile materials cannot predict the erosion rate of the composite. The presence of TiC particles in the composite increased, rather than decreased the erosion rate even though the particles obviously increased the hardness of the composite. Erosion process involved the displacement of the target material and the removal of the displaced material. By comparison to the monolithic alloy, the composite exhibited higher resistance to the displacement of the target material due to higher hardness, while lower resistance to the removal of the displaced material due to poor ductility. The combined effect from these two aspects resulted in a higher erosion rate of the composite than that of the monolithic alloy.