Influence of composition and process parameters on the thermal spray deposition of UHMWPE coatings

Abstract

Ultra-high molecular weight polyethylene (UHMWPE) has remarkable properties in the bulk state and has substantial potential for use as a protective coating on metals. However, the molecular architecture responsible for these exceptional properties also causes difficulties in the formation of coatings by thermal spraying. This paper studies the effect of molecular weight, particle size and the influence of the addition of low-molecular weight binders on the structure and properties of combustion flame sprayed coatings. The flow of splats for each UHMWPE polymer and blends of selected polyethylenes was characterized by microstructural analysis and the performance of the resulting coatings evaluated by mechanical testing. A computational model was developed to calculate the temperature profiles of in-flight particles and to simulate the behaviour of particles during deposition. The model was applied to the polyethylene system and the experimental results show that the composition, the particle size and the process parameters are important factors in the optimization of coating quality.