industrial processes ii industrial processes ii inden 3313 lecture 4 – completion of finishing;...

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


OVERVIEWOVERVIEW

• Return of HomeworkReturn of Homework• Questions to Start/ErrataQuestions to Start/Errata• FinishingFinishing

– Process Descriptions– Parameters/Impact on Surface Finish

• TreatmentsTreatments• CoatingsCoatings• CleaningCleaning


QUESTIONSQUESTIONSTO START ??TO START ??

Errata --Errata --


HONINGHONING• IllustrationIllustration

Groover Figure 26.19, p 675


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


LAPPINGLAPPING• IllustrationIllustration

Kalpakjian, Figure 25.31, p.815


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


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


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


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


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


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


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


FLOAT POLISHINGFLOAT POLISHING• IllustrationIllustration



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


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.


BARREL FINISHINGBARREL FINISHING• IllustrationIllustration

Groover, Figure 32.2, p. 816


BARREL FINISHINGBARREL FINISHING• Illustration Of Pellet ShapesIllustration Of Pellet Shapes

Groover, Figure 32.3, p. 817


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”


• IllustrationIllustration


ABRASIVE FLOWABRASIVE FLOW


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


ABRASIVE JETABRASIVE JET• IllustrationIllustration



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


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


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


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


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


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


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



– 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



– 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)


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


CLEANINGCLEANING• DefinitionDefinition

– Removal of Contaminants from Surfaces• Dirt, Oils, Moisture, …

• TypesTypes– Mechanical

• Brushing (Wire)• Blasting (Abrasive Jet)• Tumbling• Steam• Ultrasonic


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)


QUESTIONSQUESTIONSOR OR

CLARIFICATIONCLARIFICATIONS ???S ???

industrial processes ii industrial processes ii inden 3313 lecture 4 – completion of finishing;...

Documents

industrial processes

smears surface layers

removal of material

process parameters electrolyte

electropolishing comparison

similar process

buffing comparison

fine soft abrasives