Experimental analysis of impact behavior of ultra-high molecular weight polyethylene-nano ceramics composite particles by isolated particle deposition method using downstream injection cold spray technique

Recent advances has made possible to obtain Ultra High Molecular Weight Polyethylene (UHMWPE) coatings by cold spray technique with nano-ceramic additives with the feedstock. However, the exact role of nano particles is largely not understood. In this work, isolated depositions of UHMWPE particles with 0%, 2%, 4%, 10% of fumed nano alumina (FNA) on Al surface were performed at different gas/particle temperatures. Particle velocities and particle temperatures were controlled by varying the carrier gas pressure and temperature. The impact behavior of UHMWPE was analyzed using SEM, FIB and high-speed camera. Increase in gas temperature and percentage of FNA showed a significant variation in the deposition volume. FIB analysis showed that successful depositions were influenced by degree of deformation of particle. Further, addition of FNA helped in deposition of particles that have required a lesser degree of deformation. Finally, high speed camera showed that particles are moving at an incidence velocity of 180-200m/s and rebound velocity of 40-50m/s. This suggests that particles lose a significant amount of their kinetic energy during the impact.