Structural analysis and mechanical properties of some coatings obtained by cold spray method. A review

Abstract

In this paper a documentation was made to highlight the characteristics obtained on surface modifications by means of the Cold Spray, using different powders based on tungsten carbide (WC) and agglomerated with nickel, sprayed on different materials, as well as the possibility of using 52100 steel, which is often used in the manufacture of rolling bearings and which has acquired high performances both in terms of wear and fatigue and in terms of high resistance due to the alloying with chromium and the high percentage of carbon. Studies on the use of WIP-C1 powders, powders attributed exclusively to the cold spraying process, and the prior use of WIP-BC1 powders, intended to establish a stronger bond between the substrate and the base layer, have shown that good wear and impact resistance is obtained and the risk of delamination and interfacial porosity has been minimised. Studies with different coating compositions using several methods to improve surface quality by surface spraying, namely HVOF (high velocity oxygen fuel), CGDS (cold gas dynamic sterilization) and CS (cold spray), led to an improvement in performance, with the cold spray process showing improved scratch resistance, good adhesion between the substrate and the sprayed layer and higher hardness. Surface spraying is an efficient process to obtain additional characteristics, improving mechanical, tribological, corrosion and erosion properties, and of all the other techniques, Cold Spray becomes competitive because it is the only technology that deposits particles below the melting point.