The US Navy has adopted High-Pressure Cold Spray (HPCS) as a repair technique for corroded and worn components in their fleet of aircrafts, ships, and submarines. HPCS repairs are not only used for depositing corrosion and wear resistant coatings but is being successfully used for dimensional restoration in metal parts and components. By utilizing HPCS, the Navy ensures the longevity and reliability of critical components, even in harsh environments. Whether safeguarding against corrosion or restoring worn parts, HPCS is playing an increasingly critical role in maintaining operational readiness for the US Navy and other DOD agencies, as well as the commercial industry.

High Velocity Oxy-Fuel Thermal Spray has been used by the Navy for repairing components for several years with great success. This paper will discuss some of the applications being done, the results of these applications and where the technology will be utilized on the future. The Office of Naval Research in conjunction with Naval Research Laboratory and Naval Surface Warfare Center is investigating replacements for chrome plating. One of the technologies being looked at is HVOF Thermal Spray. This paper will discuss this program, new materials being developed and new applications being done. The superior physical characteristic of HVOF has increased the utility of this technology from mechanical components to aircraft and submarine components. Acceptance of these coatings at various levels at NAVSEA will be discussed and criteria established for these acceptances will be reviewed. The role of these coatings in ship repairs as well as the implications for new construction will be discussed. Specific examples of repairs will be shown and updated reports will be provided as to their service. Locations that have services available will be detailed and future growth of this technology within the Navy will be reviewed. A quick overview of similar emerging technologies will be provided. A highlight of the presentation will be an update of the repair done with HVOF Tungsten Carbide on the Rudder Rams on the USS Saipan.

This paper summarizes the results of a decade-long study on nanoparticle reconstitution and its role in thermal spraying. The effect of the reconstitution process on coating nanostructure was investigated for different materials and applications, a number of which are covered in this report, including Al 2 O 3 -TiO 2 , SiC-Al 2 O 3 -ZrO 2 , and zirconia-based TBCs.

Naval ship components are subject to extreme operating conditions while at sea, either during regular sailing periods and/or during training exercises. The Chilean Navy has employed thermal spray technology since the early 1960 decade. By setting up a joint cooperative program between the Chilean Navy industry and suppliers, it has been possible to start regaining confidence in thermal spraying and positioning the same as a "must" technology in regular naval maintenance work. This article presents a description of the Naval Components Reclamation Program and discusses the processes involved in hard chrome plating replacement in naval components. It provides a review of characteristic thermal spray applications developed by the Joint Naval Components Reclamation Program.

This paper provides an update on the state of cold spray corrosion mitigation and repair as it applies to equipment operated by the U.S. Navy. It also presents several application scenarios in which cold-sprayed Al 6061 and NiCr-CrC can improve preventative maintenance and dimensional restoration procedures currently used on A36 steel and CuNi structures.

Nanostructured and conventional ZrO 2 coatings were deposited by plasma spraying. The wear and friction properties of these coatings against stainless steel under dry and water lubricated conditions were comparatively studied respectively. The results obtained showed that the wear resistance of the coating produced using the nanostructured zirconia powder is greatly improved compared with the coating produced using the conventional powder. The wear rates of the nanostructured zirconia coatings are two-fifths and half of those of conventional zirconia coating under dry and water lubricated conditions. It is explained in terms of the optimization of microstructure and higher microhardness of the nanostructured coating. In comparison with the dry condition, the water lubrication improved the tribological properties of both nanostructured and conventional zirconia coatings, which could be attributed to the formation of a smooth surface mainly consisting of zirconia and Fe 3 O 4 .

A new coating process called polymer thermal spraying (PTS) was recently developed to accommodate the deposition of heat sensitive polymeric materials over a broad range of substrates. The novel process uses an electro-resistive element to heat the main process gas, which could be air, any pure gas, or gas mixture. This paper describes the process and presents three case studies in which it is used to produce blast mitigation coatings for civil structures, super-hydrophobic coatings for corrosion protection, and flame resistant polyimide syntactic foams for thermal insulation.

Crevice corrosion of metal/metal contacts in piping assemblies is a key issue for the design and the manufacturing of marine components. In this work, ceramic coatings onto alloy 625 were obtained using multi-processing CAPS facilities (Controlled Atmosphere Plasma Spraying). These coatings were sprayed in the CAPS chamber using air plasma spraying (APS, air at 100 kPa) or using high-pressure plasma spraying (HPPS, argon at 250 kPa) to achieve different coating microstructures and porosity levels. This allowed to investigate the corrosion behaviour in natural sea water of metal/ceramic contacts with different coating systems. Pure alumina or alumina-titania coatings with or without thermally-sprayed alloy 625 bond-coat were tested. Post-treatments like sealing of pores using epoxy resin were also achieved to study the resulting corrosion protection enhancement. Immersion and potentiostatic tests at +300 mV vs. SCE (Standard Calomel Electrode) tests were carried out in natural sea water at different temperature up to 60°C to expose specimens to the most severe working parameters. A beneficial protective effect of ceramic-coated alloy 625 has been clearly evidenced. Further investigations were performed using light microscopy and scanning electron microscopy to assess the corrosion behaviour and mechanical soundness of ceramic coated specimens which resulted in the determining of relevant technological solutions to prevent the risk of corrosion.

In this study, a novel strategy to manufacture high strength cold-sprayed Al coating by using powder with wide size distribution is proposed. The microstructure and mechanical properties of deposited coating sprayed at three typical impact velocities before and after heat treatment are investigated. Furthermore, the deposition and strengthening mechanisms of the coating sprayed at various impact velocities are clarified. The results show that the coating with higher density and mechanical properties can be successfully fabricated by cold spray at comparatively low particle impact velocity. The mechanical properties were enhanced with the contribution of heat treatment process. It is the in-process tamping effect induced by larger powder that results in the severe plastic deformation thus leads to densification and excellent mechanical properties of the cold-sprayed Al coating.