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:red_flag: COATING TECHNOLOGY :black_flag:, electrolyte factor:, cathode:…

- - - - Binder Adhesive component of material
      - Volatile Components makes liquid fluid enough and evaporate during and after application
      - Pigments insoluble material that forms the colour and opacity of coating
      - Additives small quantity to modify material properties.
    - - bar coater
        
        bar coater tool is used to apply a controlled thin liquid layer
      - flow coating
        
        method of applying the coating on a substrate vertically suspended which material will flow via gravity pull.
      - dip coating
        
        pull substrate that is immersed in solution of thin layer which later will evaporated and form thin layer of polymer.
      - roll coater
        
        roll coating is when roll to roll method is used for apply the material on substrate. reverse rollers and nips are used to apply thin layer on substrate.
      - extra: knife over air, spray, slot die, gravure
    - - curing oven: to remove limited amount of
      - consists of : drying box, control air movement, heating element, sample cooling
  - - - process
        
        type of Al anodizing
      - working steps:
        
        type of formation:
        
        porous anodize
        
        acidic electrolyte, to form al oxide that dissolves in solution and can be few hundreds micrometer thick
        
        dye is added inside the pores and then hot water sealing is done to form hydrous oxide crystal
        
        clear anodizing is when produced in sulfuric acid
        
        Hard anodizing is done in result of formation high density coating with large cells and small pores
        
        1 more item...
        
        barrier anodize
        
        formed in near neutral electrolyte solution where the al oxide does not dissolve in solution and can be only 1 micrometer thick
    - - aerospace exterior
      - vehicle components
      - aesthetic for architectures
  - - - metal ion deposited on surface of substrate via external power supply
        
        principle
      - methods
        
        prepare with cleaning sample with acid and tape region wanted to electroplate
        
        melt wax in ventilated space
        
        cover wax and then once dried peel off tape
        
        electroplate based on parameter
        
        clean off with soapy water and heat to melt wax and polish if needed.
        
        applications
        
        automobile and motorcycle chrome parts
        
        steel or aluminium part of light fixtures
        
        jewellery
        
        common bolts, nurts and washers.
      - 4 types:
        
        rack plating
        
        continuous plating
        
        line plating
        
        mass plating
    - - in open circuit, metal deposited on substrate via redox reaction
        
        principle
        
        applications
        
        done with redox reaction as in open circuit
        
        only one electrode is used
        
        solution has reduction agent
        
        metal ion + reduction solution turns to metal solid + oxidation solution
      - characteristics
    - - displacement reaction of metal from solution onto substrate
        
        principle
        
        application
        
        weakness
- - - - application
      - Refractory ceramic coating is a layer of ceramic applied to substrate surface using very high temperature exposure
      - substrate is not heated, the velocity of particle is the important aspect.
    - - plasma/arc/flame is used to melt powder or wire material and then shot in high velocity which deforms and cooled rapidly
      - rod method
        
        gas flame of oxyacetylene melt the rod which then spraed at high speed
        
        speciality: material will only leave nozzel when it melts
      - arc spray method
        
        arc between two wire will melt the the wire and it will be accelerated via gas stream. velocity at 100-300m/s and suitable for electrical conductive material
        
        advantage : doubled spray capacity, higher bonding strength, larger compressive strength.
      - flame powder
        
        coating material move into spray via gas flow or gravity and then oxyacetylene flame partially melt the material and it will fuse to metal
        
        parameter: flame adjustment, flow rate, distance of nozzle, substrate surface
      - plasma powder
        
        an inert gas ionized between two electrode, which then have high particle velocity at range of 150- 500m/s
        
        mechanism: powder particles are injected into hot plasma and thereby melted and hit the surface at high speed.
      - detonation powder
        
        some quantity of material are exploded at rate of 4-8 times/sec. material is produced at high velocity and hit substrate
        
        properties: strong bonding to substrate
    - - solid-state coating deposition where high thermal loads, producing coat of low porosity and oxygen content. produce thich coating without any melting
      - troweling
        
        used for inaccessible areas where thickness at 25 mils is applied. Net is used for good mechanical bonding, coating plague is troweled and cooled
      - spraying
        
        substrate prep by chemical cleaning. Then, spray coating (water is added for better spraying), heat the object for strong binding, fine-grinding is done. (thickness at 1-250mils)
  - - - workings?
        
        Advantages and Applications
        
        good paint base, protect from corrosion, good electrical properties, easy to apply
        
        adhesive for paints, inexpensive protective coating,electric cabinetry, metal that cant be anodized, touch up damaged anodize or paints.
        
        a thin layer of phosphate compound adhere to the surface of metal via
    - - workings?
        
        Advantages and Applications
        
        corrosion resistance (when oiled) , appearance, low cost, dimensional stability
        
        used in rail track, toolings, precision bearing, firearms
        
        chemical reaction on surface of iron forming magnetite on surface
    - - workings?
        
        Advantages and Applications
        
        corrosion protected (when oiled), good paint and oil base, hold lubrication well, protect base well
        
        retain oil on weapon parts, adhesion to lube and paint for steel part, cam shaft/gears
        
        a thin layer of phosphate compound adhere to the surface of metal via
    - - A chemical conversion coat to form a thin protective layer on surface by having chemical reaction between metal and chemical solution
        
        used for undercoating and a adhesive based
        
        offers no resistance to wear and abrasion
        
        economy and speed is the main attraction
      - Flow
        
        Alkaline cleaning
        
        rinsing
        
        acid cleaning
        
        rinsing
        
        Conversion coating
        
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    - - heated oven
      - wiping
      - infra red lamps
      - draining
      - compressed air
  - - - enhance mechanical/physical properties such as: lubricity, flexibility, thickness
        
        smooth, high durability , resistance to chemical, high wear and tem resistance
    - - process and work
        
        Porcelain enamel is a thin layer of glass or ceramic on metal to :
        
        protect surface from chemical or physical attack
        
        improve appearance for decoration
        
        enhance mechanical properties with lowest cost
        
        mixture and prep of frits : Enamel glass is unfired mixture with is mixed and smelted at high temp and the composition of frit is determined. Different metal has different frit compositions.
        
        preparation of substrate : most common metal like copper or aluminium has its surface cleaned from all kind of contaminants via degreasing, etching, pickling and others.
        
        enamel coating : enamel is applied via dipping, slushing, brushing, spraying and bepowdering
        
        wet: enamel is applied in slurry suspension form
        
        dry: powder is sprinkled to cover red hot ground coat with more enamel.
        
        put the coated metal body to oven or furnace with certain firing temp to improve adherence between coating and substrate and improve opacifying, color. the firing parameter is strictly controlled
      - specially formulated, high durable glass powder permanently fused to metal via high heat.
    - - colour retention, UV resistance, durable, flexible desgin, surface finish
      - rust easily if chipped and extreme poor heat conduction
- - - - no chemical reaction
        
        thin and uniform film produced
      - source become vapour and then solid
        
        relies on thermal energy
        
        electrical resistance or electric beam for heat
        
        material melts and vaporizes and then deposited on substrate
        
        shield is provided between source metal and substrate
        
        pros and cons
        
        thin films and useful for semiconductor device, food packaging and fabrication tools
        
        extreme difficult to coat undercuts, high capital cost, require skilled operators, large amount of heat required and low rate of deposition
  - - - forced convection transport reactant which is the diffused to substrate surface. adsorption of gas reactant onto heated wafer, chemical decomposition and other surface reaction occurs. then deposits diffuse along the surface forming the crystallization centre and growth of film. desorption of by-product from surface. then by product is transport by diffusion
      - pros and cons
        
        flexible shape surface, versatile, high dense, pure, uniform, economical relatively, good adhesion
        
        chemical hazard, difficult to deposit multi components, use of more sophisticated reactor and vacuum system.
        
        application
        
        dense structural part, optic fibres, composities, nanomachine,semiconductors, high temp protection, corrosion and wear resistance
- - - - baths have short life usage
- - - - Al oxide layer grows on aluminium
        
        Dyes is added to porous type
        
        placed in boiling water to seal the pores( porous type)