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Industrial Processes II
INDUSTRIAL PROCESSES IIINDUSTRIAL PROCESSES II
INDEN 3313INDEN 3313
Lecture 4 – Completion of Lecture 4 – Completion of Finishing; Treatments, Finishing; Treatments, Coatings, and CleaningCoatings, and Cleaning
Industrial Processes II
OVERVIEWOVERVIEW
• Return of HomeworkReturn of Homework• Questions to Start/ErrataQuestions to Start/Errata• FinishingFinishing
– Process Descriptions– Parameters/Impact on Surface Finish
• TreatmentsTreatments• CoatingsCoatings• CleaningCleaning
Industrial Processes II
QUESTIONSQUESTIONSTO START ??TO START ??
Errata --Errata --
Industrial Processes II
HONINGHONING• IllustrationIllustration
Groover Figure 26.19, p 675
Industrial Processes II
HONINGHONING• Comparison to GrindingComparison to Grinding
– Universal Joints Enable Stone to “Follow the Hole”• Highest Pressure/Abrasion at Smallest
Diameters– Precision Hole Size, Finish
• Center Compliance Assured, Cross Hatched Pattern – Hold Lubrication in Hole
– Process Parameters• Abrasive Material• Grit Size• Pressure Used• Adhesive Used (Bond)• Hone Speed
Industrial Processes II
LAPPINGLAPPING• IllustrationIllustration
Kalpakjian, Figure 25.31, p.815
Industrial Processes II
LAPPINGLAPPING• Comparison to GrindingComparison to Grinding
– Both Lap and Work Move (Same Grain Never in Same Location on Workpiece• Abrasives in Slurry
– Low Pressure– Able to Move in Response to Cutting Forces
– Process Parameters• Abrasive Material• Grit Size• Slurry Consistency• Lap/Work Speed
Industrial Processes II
POLISHINGPOLISHING
• DescriptionDescription
– Fine Abrasive Powders Are Used to Coat Fabric, Leather, Felt, … Disks or Belts
– Coated Disk or Belt Rubbed on Surface to be Finished
– Fine Abrasives Remove Material
– Friction Heating Softens and Smears Surface Layers
Industrial Processes II
POLISHINGPOLISHING• Comparison to GrindingComparison to Grinding
– Very Soft Backing Material (Cloth)– Fine Abrasives (May be in Slurry)– Low Pressure
– Process Parameters• Abrasive Material• Abrasive Particle Size• Backing Material• Pressure Used
Industrial Processes II
BUFFINGBUFFING• DescriptionDescription
– Similar to Buffing with Softer Backing and/or Softer and/or Finer Abrasives
– Also Known as “Compounding” from the term “Buffing Compound”
– Extremely Fine Surface Finish Obtainable
Industrial Processes II
BUFFINGBUFFING• Comparison to GrindingComparison to Grinding
– Very Soft Backing Material (Cloth)– Very Fine Soft Abrasives (May be in
Slurry)– Low Pressure
– Process Parameters• Abrasive Material• Abrasive Particle Size• Backing Material• Pressure Used
Industrial Processes II
ELECTRO-POLISHINGELECTRO-POLISHING• DescriptionDescription
– Placement of Workpiece in Electrolytic Solution
– Application of Electrical Potential to Workpiece
– Ions (Charge) Collects on Outer Surface of Part
– Ions Go Into Solution (Dissolve)– Highest Surface Goes Into Solution
Most Rapidly
Industrial Processes II
ELECTRO-POLISHINGELECTRO-POLISHING• Comparison to GrindingComparison to Grinding
– Removal of Material via Electro-Chemical Means (NOT Shearing/Metal Cutting)
– Process Parameters• Electrolyte Used• Strength of Potential (Voltage)• Duration of Applied Potential
– Can Use a Similar Process With Metal Grinding Wheel – Grinding Fluid is Electrolyte and Known as Electro Chemical Grinding
Industrial Processes II
FLOAT POLISHINGFLOAT POLISHING• IllustrationIllustration
Kalpakjian, Figure 25.32, p.816
Industrial Processes II
FLOAT POLISHINGFLOAT POLISHING• Comparison to GrindingComparison to Grinding
– Pressure Supplied by Magnetic Forces• Magnetic (Metallic Abrasives) Pulled Onto
Workpiece Via Strength of Magnetic Field• Permanent or Electro-Magnets Used• Used on Ceramic Ball Bearings• Pioneered at OSU
– Process Parameters• Abrasive Material• Grit Size, Slurry• Strength of Magnetic Field• Rotational Speed
Industrial Processes II
BARREL FINISHINGBARREL FINISHING• DescriptionDescription
– Parts and (Dry Pellets) Abrasive are Placed into a Container
– Container is Rotated– As Container Rotates the Parts
Shift/Slide Against One Another (with the Abrasive Between Them) and the Weight of the Parts Provides the Pressure for the Abrasion Process.
Industrial Processes II
BARREL FINISHINGBARREL FINISHING• IllustrationIllustration
Groover, Figure 32.2, p. 816
Industrial Processes II
BARREL FINISHINGBARREL FINISHING• Illustration Of Pellet ShapesIllustration Of Pellet Shapes
Groover, Figure 32.3, p. 817
Industrial Processes II
BARREL FINISHINGBARREL FINISHING• Comparison to GrindingComparison to Grinding
– Lower Pressure– Slower Speeds– Shaped (Loose) Abrasives
– Process Parameters• Abrasive Material• Abrasive Pellet Shape• Ratio of Parts to Abrasive• Rotational Speed
– Also Known as “Tumbling”
Industrial Processes II
• IllustrationIllustration
Kalpakjian, Figure 25.33, p.818
ABRASIVE FLOWABRASIVE FLOW
Industrial Processes II
ABRASIVE FLOWABRASIVE FLOW• Comparison to GrindingComparison to Grinding
– Lower Pressure– Slower Speeds– Abrasive Slurry
– Process Parameters• Abrasive Material• Abrasive Slurry “Stiffness”• Pressure Forcing Slurry Through/Around
Part
Industrial Processes II
ABRASIVE JETABRASIVE JET• IllustrationIllustration
Kalpakjian, Figure 26.20, p.847
Industrial Processes II
ABRASIVE JETABRASIVE JET• Comparison to GrindingComparison to Grinding
– “Soft” Backing (Air)– Small Depths of Cut (Bounce Off)– Abrasive is “Loose”– Peens Surface
– Process Parameters• Abrasive Material• Abrasive Particle Size and Shape• Angle of Incidence
– Also Known as Sand Blasting, Bead Blasting
Industrial Processes II
SURFACE TREATMENT SURFACE TREATMENT AND COATINGAND COATING
• GoalsGoals– Improve Hardness (Wear Resistance)– Reduce Adhesion– Improve (Retention) of Lubricants– Improve Corrosion Resistance
• Barrier Methods• Insulation Methods
– Improve Fatigue Resistance– Build-up/Restore Worn Surfaces– Modify Surface
• Smoother or Rougher• Color
Industrial Processes II
SURFACE TREATMENTSURFACE TREATMENT• DefinitionDefinition
– Changes Metallurgy (Crystalline Structure) of Metallic Parts Using Pressure or Heat
• TypesTypes– Mechanical (Cold Working)
• Shot Peen/Hammer Peening– Hit Surface with Ceramic or Steel Shot or Hammer
• Roller/Ball Burnishing– Use Surface Rollers to Plastically Deform Surface
• Explosive Hardening– Use High, Transient Force Application to Cold
Work Surface
Industrial Processes II
SURFACE TREATMENTSURFACE TREATMENT• TypesTypes
– Thermal• Flame and Induction Hardening
– No Material Added, Smaller Grains at Surface– Heat and then Cool Surface/Part– Usually an “Air Quench” Process
• Anneal– Heat/ Soften Surface via Annealing– Often Done in Furnace
• Case Hardening– Material Added, Carburizing, Nitriding, ... – Heat To Assist in Diffusion into Surface then
Cool Surface– Parameters
» Temperature, Time, Pressure
Industrial Processes II
COATINGSCOATINGS• DefinitionDefinition
– Processes which Add Materials to the Base Component(s)
• TypesTypes– Mechanical (Apply Particles onto
Surface)• Cladding
– Roll Thin Layer onto Base Metal (Alclad, Zn Coated Steel
• Mechanical Plating– “Throw” Metal Particles/Powder onto Surface
» Analogy – Snow Ball onto a Brick Wall
• Painting
Industrial Processes II
COATINGSCOATINGS• Types (cont.)Types (cont.)
– Thermal (Coat w/Molten Material)• Thermal Spraying (Metallizing)
– Liquid Metal Spray Produced by Combustion/Heating to Melt Metal in Nozzle and use Escaping Gas to Expel Molten Metal at Speed onto (cool) Surface.
– Parameters/Concerns» Temperature, Gas , Gas Pressures» Oxydation (vacuum)
– Done at OKC Air Logistics Center to Rebuild Worn Jet Engines
Industrial Processes II
COATINGSCOATINGS• Types (Cont.)Types (Cont.)
– Thermal• Hard Facing
– Harder Material Added to Surface – Melt a Filler Rod onto a Surface Rather Using
an Electric Arc or Oxyfuel Heat Source– Often, Some Melting of Base Surface
• (Hot) Dipping– Dip part to be Coated in Molten Metal– Galvanization (Zn Coating)
• Enameling (Coat and Fuse with Heat)– Enameling of Steels, …– Glazing of Ceramics
Industrial Processes II
COATINGSCOATINGS• Types (cont.)Types (cont.)
– Physical Vapor Deposition• Vacuum Evaporation
– Evaporate metal to be deposited at high temperature
– Let condense on cool part– Uniform Coating (Simple and Complex
Shapes)– Parameters
» Temperature Difference, Exposure Time
• Sputtering– Use of ionized inert gas to bombard cathode,
causing sputtering (ejection) of its atoms and subsequent condensation of the metal atoms on anode
Industrial Processes II
COATINGSCOATINGS• Types (cont.)Types (cont.)
– Chemical Vapor Deposition• Thermochemical process – a reaction
produces desired coating in an inert atmosphere – TiN Coating of Cutting Tools
– Chemical• Electroplating, Plating, Electroforming
– Deposition of ions from solution onto base» Electroplating, Electrical Current Used» Plating, No Current – Uses Reduction Reaction» Electroforming, Current, No Base Metal Coated
– Parameters» Current Density, Voltage, Time» Part Shape (Affects Uniformity of Coating)
Industrial Processes II
COATINGSCOATINGS• TypesTypes– Chemical (cont.)
• Anodizing (Oxidizing Aluminum)– Produces porous oxide (hard) layer on surface
via emersion of electrolytic cell in acid bath -- oxygen adsorption by metal – can add color (dyes)
• Conversion Coating (Surface Reactions)– Naturally occurring oxides are formed on
surfaces via chemical or electrochemical reactions; colors can be produced from some reactions (black oxides on iron steels)
• Sol-Gels– OSU Research on corrosion resistance for
aging aircraft
Industrial Processes II
CLEANINGCLEANING• DefinitionDefinition
– Removal of Contaminants from Surfaces• Dirt, Oils, Moisture, …
• TypesTypes– Mechanical
• Brushing (Wire)• Blasting (Abrasive Jet)• Tumbling• Steam• Ultrasonic
Industrial Processes II
CLEANINGCLEANING
• TypesTypes– Chemical
• Solution (Dissolves Dirt into Solution)• Saponification (Convert Oils to Soap)• Emulsification (Suspend in Emulsion)• Dispersion (Reduce Concentration, Dilute)• Aggregation (Collect Particles, Remove
Collection)• Pickling (Acid or Alkaline to Dissolve)
Industrial Processes II
QUESTIONSQUESTIONSOR OR
CLARIFICATIONCLARIFICATIONS ???S ???