A. R. Phani and S. Santucci

1. CNR-INFM Sol-gel Process Sol-gel Coatings Applications ADVANTAGES • Corrosion • Abrasion • Erosion • Scratch • Anti-adhesion • Anti-finger print • Anti-fouling • Antibacterial • Uniformity • High purity • Easy Operation • Cost Effective • Low temperature • Controlled structure • Coating on irregular shapes • Selective doping • Smart windows • Sun roofs • Capacitors • Semiconductors • Heat insulating • Memory devices • Dispalys • Wave guides • Metal Alkoxide (M-O-R) • Sol • Solution • Hydrolysis and Condensation • Polymerisation • Applications • Properties • Magnesium has a number of unique physical and mechanical properties which, depending on strength, safety and weight aspects can be used by automotive, aerospace and electronic goods designers • Light wieght (36% lower than Al) • High strength to weight ratio • High stiffness to weight ratio • Excellent damping capacity • Castability, mechanibility, recyclibility • Biosensors • Implant coatings • Gas sensors • Hydrophobic • Photocatalytic FACTORS EFFECTING • Coating • Coating • Energy storage • Fuel cells • Solar cells • Laser diodes • Decorative • Getting • Spinning • Wet gel • pH (acid / base) • Temperature • Water and Solvent • Reagent concentration • Catalyst • Dipping (spinning) speed • Precipitating • Xerogel film • AUTOMOTIVE WEIGHT SAVINGAEROSPACE • Fuel consumtion • Emission • Safety • Braking • Dynamic • Furnace • substrate • Extraction of solvent • Evaporation • Xero gel • Heating • Heating • substrate • Fibers • Dense Film • Dense ceramics • Uniform particles • Aero gel • Building – construction • Technology • Aeroneutic • Industry • Chemical • Industry • Functional • Thin Films • Protective • Films • Membranes • Thin films • Sol-gel • Technology • Applications • Automotive • Coatings • Optical • Coatings • Reinforcing • Fibers • Nano- • particles • Fibers • Powders • Composites • Smart • Materials • Emulsion • Powders • Aviation • Engineering • Bio-medical • Engineering • Nanostructures Solar • Technology Protective Space coatings for Ti, Al and Mg alloys: Nanoscale materials based on organically modified ceramics A. R. Phani and S. Santucci CNR-INFM CASTI Regional Laboratory at Department of Physics - University of L’Aquila, via Vetoio, 67010 Coppito, L’Aquila, ITALY Tel: 0039-0862-433037 Fax: 0039-0862-433033 e-mail: sandro.santucci@aquila.infn.it or phani_ayala@yahoo.com Motivation – Objectives Mg and its Space ApplicationsInnovative approach • The main objective of this proposal is to protect space materials from corrosion such as Ti and Mg alloys with nanostructured- multifunctional coatings. • In the proposed system, deposition of nanolayering of inorganic and organic nanocomposite materials embedded with nanoparticles (corrosion inhibitors) with additional functional groups on the surface will be developed. • These nanocomposite materials will be prepared by simple, wet chemical processing system (sol-gel process) at relatively low temperatures (> 150 °C). • The basic structure consists of inorganic network with organic cross-linking or network modifying structural units. A main advantage of this system is the combination of hardness (coming from the high amount of inorganic network structures) and flexibility (coming from the nature and amount of cross linking structures). • This could be possible by covalently bonding the networks leading to stable functionalisation and incorporating the corrosion inhibitor nanoparticles with in these networks to have corrosion resistance properties. • Aerospace Value of a pound in • segnment weight saved (Euro) • Commercial -------------------- 357 • Space ----------------------------- 35.4 • Automobile --------------------- 1.78 – 3.2 • Radical Innovative Approach: • This type of system will be applied on different types of Titanium, Magnesium and Aluminium alloys applicable to aerospace applications. • It has been recognised by the aerospace industries that the degradation of carbon-based materials (organic coatings) in low earth orbit (LEO) is due to the presence of ground state atomic oxygen, ultra-violet radiation and vehicle’s extreme velocity. • The UV radiation that is present in low earth orbit is of adequate energy to cleave organic bonds, which can bring about chain scission and cross-linking reactions in organic polymeric materials. In addition to this, thermal cycling, particulate radiation, vacuum, and micrometeoroids and debris affect organic materials. • In this respect, materials consisting of inorganic/organic (polymer) can offer protection from atomic oxygen as well as UV radiation and high- energy particles via the in situ fabrication of nanophase silicon / metal-oxo clusters. • Siloxane polymers, which have rates of erosion one to two orders of magnitude slower than organic polymers in low earth orbit, have been chosen in the present investigation. • In addition, to slower erosion rates, when exposed to atomic oxygen siloxane polymers form protective silicon oxide barrier. • This provides enhanced atomic oxygen resistance, and will offer a self-healing property if the coating is scratched or etched from the debris. • The silica layer on the surface prevents further degradation of the polymer underneath with increased exposure to atomic oxygen. Fig 1: Schematic diagram of the nanoscale hybrid structure for multifunctional properties for light-weight alloys applied for space applications Background • Magnesium alloy has a light weight, high thermal conductivity, high dimensionalstability, good electromagnetic shielding, high damping characteristics, good machineability and as well as recyclability • These properties make it valuable in a number of applications including automobile, aerospace components, mobile phones, sporting goods, handheld tools, and household equipment • The use of magnesium alloys can significantly decrease the weight of automobiles without sacrificing structural strength • Unfortunately, magnesium alloys have a number of undesirable properties including poor corrosion and wear resistance, poor creep resistance, and high chemical reactivity that have hindered its widespread use in many applications • The proposed mechanism explains where a space debris erode a part of coating which • is self healed by consuming the atomic oxygen present in the space, there by forming a • new protective layer which can withstand both atomic oxygen degradation, high energy • UV radiation and atomic particles. • Once the coating is exposed to atomic oxygen a protective layer of silicon oxide • is formed and with the incorporation of silicon-metal-oxy-clusters the coating should • protect against atomic oxygen erosion, high energy particles, and deep UV radiation. Sol-gel ProcessSol-gel Nanotechnology Applications Project Goals Scientific and Technological Objectives that CASTI might pursue in this project: To optimize the developed pretreatment process for light weight alloys prior to the deposition of the nanostructured coatings for better adhesion strength To deposit organic-inorganic hybrid nanocomposites embedded with functional corrosion inhibitor nanoparticles (CeO2, La2O3) To deposit low friction, wear, scratch, abrasion resistant inorganic-polymer hybrid nanostructured coatings as top layer with additional hydro-oleophobic properties to fulfill the objective of the multifunctional coatings. To characterize the deposit or thermally treated coatings for their structural, mechanical, tribological and corrosion (salt spray) and humidity resistance (intermittent, prohesion, and condensation humidity tests) measurements. To optimize the developed nanocomposites embedded with nanoparticles for scale up process upon dealing with the industrial partners in the respective countries in the field of automobile, aeronautic, construction and microelectronic industries. Services offered by CASTI in the project: CASTI will analyze the coated samples as well as corrosion resistance tested (salt spray test) samples by employing full length scale characterization techniques available in the laboratory.