The fraction of the ductile component of the fracture surface after solid particle erosion for different materials was
investigated. The minimum amount of viscous fracture on the fracture surface was observed in aluminum samples with the
FCC lattice and very high stacking fault energy, and the maximum was found in copper samples with the same FCC lattice
but small stacking fault energy. The percentage of viscous fracture in BCC steel samples is close in magnitude to titanium
alloy with HCP + BCC lattice and they occupy an intermediate position between copper and aluminum samples.