Nanotechnology nickel cobalt iron alloy plating.doc

Nanotechnology nickel cobalt iron alloy plating hard chrome alternativeReplace chrome coatings of nickel-cobalt-iron platingThe aircrafts landing gear, hydraulic actuators, gas turbine engines, helicopter dynamic components and the propeller hub hexavalent chromium system chromium coatings. However, recent electrodeposited nanocrystalline cobalt-phosphorus X alloy, the development China Yantai plating technology, national defense and security partners, has come on the scene. Its characteristics, in many ways better than chrome, to overcome the environmental constraints, can provide better performance and lower life-cycle costs.Works hard chrome plating (EHC) coatings 0.00025-0.010 inch thick, is widely used in aerospace applications components impart wear and corrosion. Hard chromium (Cr6 +) bath used in a variety of aircraft components in the manufacture and repair / overhaul business.In the undercarriage, for example, the ID of the outer cylinder is often wear and corrosion resistance of the chromium plating. Undercarriage member and the hydraulic actuator internal chromium plating is the most common. Plating for this application, it will be difficult or impossible to coat potential alternative technology development since many of the line of sight (LOS).Unfortunately, the toxicity of hexavalent chromium, a significant reduction of its use. OSHA, for example, the recent reduction in the permissible exposure limit for hex chrome compounds 52-5 concentration for the 8-hour time-weighted average. The rule also provides protection for employees, such as controlling exposure, respiratory protection, protective clothing and equipment, hygiene areas and practices, medical surveillance, hazard communication of information and records saved the best way.In addition the health risks associated with hexavalent chromium, as well as other processes and performance with the use of chrome paint shortcomings. The chromium plating Usually electrolysis efficiency having a relatively low, resulting in low deposition rate compared to other plating metals and alloys. The hexavalent chromium inherent brittleness will inevitably lead to the micro-or macro-cracks deposits. These cracks do not endanger the wear and erosion resistance, but they are completely unsuitable for corrosion resistance is required applications. In these applications, an electrodeposited underlying a more ductile and corrosion resistant material is usually nickel-cobalt-iron must be applied.The landing gear hydraulic cylinder is the geometry of the components, not suitable for them as well as a good example of the thermal spraying and similar LOS process.Therefore, the health and safety restrictions and process / performance deficiencies in the electroplating industry there is huge pressure to find a more environmentally sound alternative to hard chrome. Consider as an alternative techniques include thermal spraying, plasma vapor deposition, electrolytic or electrolytic plating techniques by applying and other chrome-free material.Tungsten carbide - cobalt (WC-Co) number in the past 10 years, and similar material, the use of high velocity oxygen fuel (HVOF) thermal spray, were part of the extensive demonstration / validation testing, the U.S. Department of Defense a replacement of hard chrome product team (HCAT) plans. These materials have been widely accepted as a suitable substitute, hard chromium in the North American aerospace industry and other small-volume, high-value-added LOS paint application. However, non-line of sight (NLOS) requirements for the application of the coating and / or deposition of high-volume, low-value-added production, it is generally believed that only plating technology will be appropriate and / or cost-effectiveness.Most investigations to date the coating alternatives based on the nickel alloys, including electroless and electrolytic material. Nickel EPA listed as a priority pollutant is considered one of the 14 most toxic heavy metals, coatings containing nickel represents a short-term solution, at best. Therefore, Yantai plating technology - nickel-cobalt-iron plating is a short-term alternative. Based on the non-nickel plating technology is a practical, environmentally acceptable alternative NLOS coating applications. Yantai electroplating technology research electrodeposited nanocrystalline cobalt-phosphorus X alloy.A photomicrograph of a cross-sectional of the deposition surface and through a 0.013 inches thick Nanovate CR coating a 1-inch diameter tube. Are interested in small grain size, and a lack of holes and micro-cracks.Nanotechnology is a relatively new field of structural design of the processing of the order of a few nanometers very small size of the critical length. Nanomaterials, the average ultrafine grain size of the material is typically less than 100 nm initial interface material, about 20 years ago. The main feature of these materials is an enhancement of the volume fraction of the interface components of the type (atomic volume fraction and grain boundaries and triple point). When the average grain size decreases below 100nm, which will become important. Atoms will lead to changes in the many mechanical, physical and chemical properties of the nanocrystalline material having such a large part of the defect structure at the interface.Nanocrystalline materials synthesis system attempts to optimize specific properties, deliberately control the grain boundaries of the material and the volume fraction of the three junctions. Since then, many nano metals and alloys have been produced by electrodeposition, include pure nickel, cobalt, palladium and copper binary alloy, such as nickel - iron, nickel - phosphorus, zinc - nickel, palladium, - Iron, cobalt - tungsten; ternary alloys, such as nickel - iron - chromium materials. Nickel cobalt iron plating.Another such material is Nanovate CR, electrodeposition of nanocrystalline cobalt-phosphorus X alloy development. LOS and NLOS applications can use the electrodeposition process, the material can be viewing part of the overall strategy to replace the current use of the environment and health process, significantly improve performance and reduce life cycle costs.Electrodeposition. Therefore, it is a drop-down alternative technologies, hard chrome plating current infrastructure is fully compatible, is very suitable for application LOS and NLOS surface. EHC, the process uses no component of the U.S. EPA or other hazardous substances on the list, it does not produce harmful emissions or byproducts.Appearance of the pit, the pores and cracks microcrack microstructure of nanocrystalline (mean grain size of 5-15nm) - less than the OSHA limit hexavalent chromium emissions analysisProcess using nanotechnology, has also led to a significant reduction in energy consumption and increase throughput. Overall plating efficiency of about 90%, less than 35 percent of the EHC. In addition, CR Nanovate deposition rates range from 0.002-0.008 IPH, depending on the current density of, typically 0.0005-0.001 IPH deposition rate seen with the ENC process.Visual, nano-cobalt phosphorous X coating uniform and smooth, shiny, similar to chrome. Under the microscope, the deposit is a fully dense structure from pits, porosity and microcracks.Metallurgy, materials having a hexagonal close-packed (HCP) crystal structure, the equilibrium structure at room temperature is usually found in the conventional cobalt. However, unlike the conventional cobalt, the material having an average grain size in the range of 5-15 nm. The test showed that the average grain size in this range results in the optimum combination of strength and ductility.* After ASTM B 537 Protection grade salt spray 1000 hours per ASTM B 117 exposureNanocrystalline alloy such as hardness and strength Nanovate CR displayed with respect to the coarse-grained, conventional significantly increased. By solid solution strengthening mechanism, the the microhardness values range generally 530-600 VHN.Annealing microhardness nano-cobalt-phosphorus deposits in different temperature and time. A brief heat treatment can significantly increase the hardness.Further increase hardness Annealing thus deposited material, can be obtained by the following manner. The hardness increase in the over 150 VHN short heat treatment process results.Nanovate CR also has improved wear and lubricity, relative to the EHC. The material has a lower abrasion loss than EHC needle on the disk sliding wear tests. The amount of wear of the mating material, in this case, the alumina balls are also less severe, and showed that the nano-cobalt - phosphorous having a lower coefficient of friction than the EHC.Corrosion resistance in the salt spray test is also improved. Exposed to salt spray environment in accordance with ASTM B 117 1000 hours, in a comparison Nanovate CR and other surfacing materials, the material ASTM B 537 Protection grade dropped to only eight less than the EHC rating 2. In addition, 50% thinner the nanocrystalline deposits than EHC and HVOF coating test for.The plating in the aerospace Another important consideration is the potential of hydrogen embrittlement in a high strength steel member. High plating efficiency Nanovate CR process causes significantly less hydrogen compared with the process of the EHC, a