Transcript advanced manufacturing systems inden 5303

INDUSTRIAL PROCESSES II
INDEN 3313
Lecture 4 – Completion of
Finishing; Treatments, Coatings,
and Cleaning
Industrial Processes II
OVERVIEW
• Return of Homework
• Questions to Start/Errata
• Finishing
– Process Descriptions
– Parameters/Impact on Surface Finish
• Treatments
• Coatings
• Cleaning
Industrial Processes II
QUESTIONS
TO START ??
Errata --
Industrial Processes II
HONING
• Illustration
Groover Figure 26.19, p 675
Industrial Processes II
HONING
• Comparison 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
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Abrasive Material
Grit Size
Pressure Used
Adhesive Used (Bond)
Hone Speed
Industrial Processes II
LAPPING
• Illustration
Kalpakjian, Figure 25.31, p.815
Industrial Processes II
LAPPING
• Comparison 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
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Abrasive Material
Grit Size
Slurry Consistency
Lap/Work Speed
Industrial Processes II
POLISHING
• Description
– 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
POLISHING
• Comparison to Grinding
– Very Soft Backing Material (Cloth)
– Fine Abrasives (May be in Slurry)
– Low Pressure
– Process Parameters
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•
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Abrasive Material
Abrasive Particle Size
Backing Material
Pressure Used
Industrial Processes II
BUFFING
• Description
– 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
BUFFING
• Comparison to Grinding
– Very Soft Backing Material (Cloth)
– Very Fine Soft Abrasives (May be in Slurry)
– Low Pressure
– Process Parameters
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Abrasive Material
Abrasive Particle Size
Backing Material
Pressure Used
Industrial Processes II
ELECTRO-POLISHING
• Description
– 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-POLISHING
• Comparison 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 POLISHING
• Illustration
Kalpakjian, Figure 25.32, p.816
Industrial Processes II
FLOAT POLISHING
• Comparison 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
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Abrasive Material
Grit Size, Slurry
Strength of Magnetic Field
Rotational Speed
Industrial Processes II
BARREL FINISHING
• Description
– 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 FINISHING
• Illustration
Groover, Figure 32.2, p. 816
Industrial Processes II
BARREL FINISHING
• Illustration Of Pellet Shapes
Groover, Figure 32.3, p. 817
Industrial Processes II
BARREL FINISHING
• Comparison to Grinding
– Lower Pressure
– Slower Speeds
– Shaped (Loose) Abrasives
– Process Parameters
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Abrasive Material
Abrasive Pellet Shape
Ratio of Parts to Abrasive
Rotational Speed
– Also Known as “Tumbling”
Industrial Processes II
ABRASIVE FLOW
• Illustration
Kalpakjian, Figure 25.33, p.818
Industrial Processes II
ABRASIVE FLOW
• Comparison 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 JET
• Illustration
Kalpakjian, Figure 26.20, p.847
Industrial Processes II
ABRASIVE JET
• Comparison to Grinding
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“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 AND
COATING
• Goals
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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 TREATMENT
• Definition
– Changes Metallurgy (Crystalline Structure)
of Metallic Parts Using Pressure or Heat
• Types
– 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 TREATMENT
• Types
– 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
COATINGS
• Definition
– Processes which Add Materials to the Base
Component(s)
• Types
– 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
COATINGS
• 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
COATINGS
• 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
COATINGS
• 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
COATINGS
• 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
• Types
COATINGS
– 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
CLEANING
• Definition
– Removal of Contaminants from Surfaces
• Dirt, Oils, Moisture, …
• Types
– Mechanical
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Brushing (Wire)
Blasting (Abrasive Jet)
Tumbling
Steam
Ultrasonic
Industrial Processes II
CLEANING
• Types
– Chemical
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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
QUESTIONS
OR
CLARIFICATIONS
???
Industrial Processes II