No abstract

The slurry erosion‐corrosion behavior of 19.5 vol.% Al18B4O33 whisker reinforced AC4C Al composite in aqueous slurry containing 3.5 wt.% NaCl and 20 wt.% silica has been investigated using a jet‐in‐slit rig. Erosion‐corrosion tests were performed with slurry having a jet velocity range 6.4 ms−1 to 15.2 ms−1 and at normal impact angle. The results indicated that the slurry erosion‐corrosion characteristics were affected by the slurry velocity and material properties. At low slurry velocities, as compared to the unreinforced alloy, the erosion‐corrosion resistance of the composite was improved because of increase in hardness as a result of whisker addition. However, steady‐state erosion‐corrosion rate was found to increase with the addition of whisker to the matrix alloy at high slurry velocities. The erosion‐corrosion rates of materials in the saline slurry were much higher than those in the water slurry even though the corrosion components were very small. It is found that the synergistic factor for the materials reduced with increasing slurry velocity although the synergism between erosion and corrosion was greater at high slurry velocity. Localized corrosion occuring in the strain‐hardened layer caused a decrease in the fracture strain of composite during erosion‐corrosion. In the saline slurry, the material removal was enhanced through cracking of flakes and detaching of whisker induced by stress and corrosion.