Particle degradation limits the reuse of powders in industrial powder-blast processes, In this paper the degradation behavior of Al2O3 powder is studied during erosion of glass substrates, Three techniques were used on original and multiply used powders: particle size measurements, single particle crushing tests, and microstrain analysis by X-ray diffraction, Combination of the three techniques shows that the degradation is dominated by flaws present in the original particles. Fracture at repeated use decreases the particle size, but by removing flaws also increases the degradation resistance of the particles.