Engineering 11 Manufacturing Processes Bruce Mayer, PE Licensed Electrical & Mechanical Engineer BMayer@ChabotCollege.edu Engineering-11: Engineering Design 1 Bruce Mayer, PE BMayer@ChabotCollege.edu • ENGR-11_Lec-09_Chp6_Manufacturing_Selection.ppt Select Manufacturing Processes Manufacturing process decisions Deformation processes Casting processes Sheet metalworking Polymer processing Machining Finishing/Joining Assembly Material-Compatibilities & Process-Capabilities Material costs, Tooling costs, Processing costs Engineering-11: Engineering Design 2 Bruce Mayer, PE BMayer@ChabotCollege.edu • ENGR-11_Lec-09_Chp6_Manufacturing_Selection.ppt Make a Mountain Bike Select Processes to Manufacture a Bike Seat Post Rear Brake Rear Derailleur Engineering-11: Engineering Design 3 Handle Bar Top Tube Saddle Fork Down Tube Front Brake Pedal (Courtesy of Trek Bicycle, 2002) Bruce Mayer, PE BMayer@ChabotCollege.edu • ENGR-11_Lec-09_Chp6_Manufacturing_Selection.ppt Manufacturing Process Decisions How to choose the specific manufacturing processes? How do the selected materials influence the choice of manufacturing processes? Would product function or performance issues influence the choice of processes? What criteria should be used to select processes? What are the Priority of the Criteria? Who makes the final decisions? Engineering-11: Engineering Design 4 Bruce Mayer, PE BMayer@ChabotCollege.edu • ENGR-11_Lec-09_Chp6_Manufacturing_Selection.ppt Design for Manuf (DFM) Guidelines Keep Functional & Physical Characteristics as SIMPLE as Possible • Simple & Sturdy parts are Easier to Make, and have Higher Reliability Design for the LOWEST COST Production Method • Critical for HI-VOLUME Parts Engineering-11: Engineering Design 5 Bruce Mayer, PE BMayer@ChabotCollege.edu • ENGR-11_Lec-09_Chp6_Manufacturing_Selection.ppt Design for Manuf (DFM) Guidelines Design for the Minimum Number for Processing Steps (what’s a “step”?) • Try to ELIMINATE Steps thru Thoughtful Product Design Specify Tolerances NO TIGHTER than Actually Needed • OverToleranced Design leads to Increased Cost thru – UnNeeded Processing Efforts – “False Positive” Scrap Engineering-11: Engineering Design 6 Bruce Mayer, PE BMayer@ChabotCollege.edu • ENGR-11_Lec-09_Chp6_Manufacturing_Selection.ppt Part-Processing Sequence Primary Process alter the (“raw”) material’s basic shape or form. e.g., • Casting • Rolling • Forging • Drawing • Molding • Extruding Engineering-11: Engineering Design 7 • That is, take a “bolb” of material and give it a basic shape; e.g. – Angle Iron – Tube/Pipe – Sheet/Plate Bruce Mayer, PE BMayer@ChabotCollege.edu • ENGR-11_Lec-09_Chp6_Manufacturing_Selection.ppt Part-Processing Sequence Secondary Process add or remove geometric features from the basic forms alter the (“raw”) material’s basic shape or form. e.g., • Machining of a brake drum casting (flat surfaces) • Drilling/punching of refrigerator housings (sheet metal) • Trimming of injection molded part “flash” Engineering-11: Engineering Design 8 Bruce Mayer, PE BMayer@ChabotCollege.edu • ENGR-11_Lec-09_Chp6_Manufacturing_Selection.ppt Part-Processing Sequence Tertiary Process surface treatments. e.g., • Polishing • Painting • Heat-Treating • Joining • Plating • Anodizing • Thin Film Coating Engineering-11: Engineering Design 9 Bruce Mayer, PE BMayer@ChabotCollege.edu • ENGR-11_Lec-09_Chp6_Manufacturing_Selection.ppt Process Selection Criteria Compatibility with Selected Materials Dimensional Accuracy and Tolerance Surface Finish Need for PostProcess Operations • e.g., Heat Treating Size & Weight Capacity Lead Time Min/Max Production Quantities Engineering-11: Engineering Design 10 Bruce Mayer, PE BMayer@ChabotCollege.edu • ENGR-11_Lec-09_Chp6_Manufacturing_Selection.ppt Cost Factors Influence of Special Desired Features Special Handling Equipment • e.g., Threaded Inserts, DoveTail Grooves Special Inspection Equipment Materials Availability Need for Special Tooling Yield • i.e., Scrap Rate PostProcess Finish Operations Engineering-11: Engineering Design 11 Bruce Mayer, PE BMayer@ChabotCollege.edu • ENGR-11_Lec-09_Chp6_Manufacturing_Selection.ppt Manuf Process Classifications Manufacturing Processes Deformation Extrusion Forging Rolling Bar drawing Wire drawing Casting Centrifugal Die casting Investment Permanent mold Sand casting Engineering-11: Engineering Design 12 Sheet Metal Bending Blanking Drawing Punching Shearing Spinning Polymer Processes Blow molding Casting Compression molding Extrusion Injection Molding Thermoforming Transfer molding Machining Finishing Boring Drilling Facing Grinding Milling Planing Turning Sawing ECM, EDM Anodizing Honing Painting Plating Polishing Bruce Mayer, PE BMayer@ChabotCollege.edu • ENGR-11_Lec-09_Chp6_Manufacturing_Selection.ppt Assembly Automated Bonding Brazing Manual Riveting Soldering Welding Deformation Processes Rolling Drawing Extrusion Forging Rolling Rollers in compression thick slab thin sheet Plastic deformation Engineering-11: Engineering Design 13 Bruce Mayer, PE BMayer@ChabotCollege.edu • ENGR-11_Lec-09_Chp6_Manufacturing_Selection.ppt Roll To Different Final Shape bloom structural ingot sheet slab billet Engineering-11: Engineering Design 14 bar or or coil rod Bruce Mayer, PE BMayer@ChabotCollege.edu • ENGR-11_Lec-09_Chp6_Manufacturing_Selection.ppt Extrusion & Drawing Extrusion Drawing Extrusion Die Drawing Die OutPut Cross Sections OutPut Cross Sections Ram Billet Engineering-11: Engineering Design 15 Billet Pulling force Bruce Mayer, PE BMayer@ChabotCollege.edu • ENGR-11_Lec-09_Chp6_Manufacturing_Selection.ppt Forging (Closed Die Version) Ram pressure Blocked preform Flash Gutter Engineering-11: Engineering Design 16 Bruce Mayer, PE BMayer@ChabotCollege.edu • ENGR-11_Lec-09_Chp6_Manufacturing_Selection.ppt Casting Processes Sand Casting Die Casting Investment (a.k.a. “Lost Wax”) Casting Engineering-11: Engineering Design 17 Bruce Mayer, PE BMayer@ChabotCollege.edu • ENGR-11_Lec-09_Chp6_Manufacturing_Selection.ppt Sand Casting Cope Core Flask Sprue Runner Parting line Drag Engineering-11: Engineering Design 18 Riser Gate Bruce Mayer, PE BMayer@ChabotCollege.edu • ENGR-11_Lec-09_Chp6_Manufacturing_Selection.ppt Die Casting Stationary Moving die die Molten metal Plunger Ejector pins Sprue Parting line Engineering-11: Engineering Design 19 Bruce Mayer, PE BMayer@ChabotCollege.edu • ENGR-11_Lec-09_Chp6_Manufacturing_Selection.ppt Investment Casting 4-part pattern tree Ceramic mold (hardened slurry) Wax pattern is cast Wax removed by melting Engineering-11: Engineering Design 20 Molten metal solidifies in cast Ceramic mold is removed Bruce Mayer, PE BMayer@ChabotCollege.edu • ENGR-11_Lec-09_Chp6_Manufacturing_Selection.ppt SheetMetal Fabrication Drawing Punching Shearing Spinning Bending Blanking Engineering-11: Engineering Design 21 Bruce Mayer, PE BMayer@ChabotCollege.edu • ENGR-11_Lec-09_Chp6_Manufacturing_Selection.ppt Deep Metal Drawing Engineering-11: Engineering Design 22 Bruce Mayer, PE BMayer@ChabotCollege.edu • ENGR-11_Lec-09_Chp6_Manufacturing_Selection.ppt Metal Spinning Engineering-11: Engineering Design 23 Bruce Mayer, PE BMayer@ChabotCollege.edu • ENGR-11_Lec-09_Chp6_Manufacturing_Selection.ppt PolyMer Processes Compression Molding Blow Molding Injection molding Transfer Molding Reaction Injection Molding (RIM) Engineering-11: Engineering Design 24 Bruce Mayer, PE BMayer@ChabotCollege.edu • ENGR-11_Lec-09_Chp6_Manufacturing_Selection.ppt Blow Molding Engineering-11: Engineering Design 25 Bruce Mayer, PE BMayer@ChabotCollege.edu • ENGR-11_Lec-09_Chp6_Manufacturing_Selection.ppt Injection Molding Engineering-11: Engineering Design 26 Bruce Mayer, PE BMayer@ChabotCollege.edu • ENGR-11_Lec-09_Chp6_Manufacturing_Selection.ppt Compression Molding Engineering-11: Engineering Design 27 Bruce Mayer, PE BMayer@ChabotCollege.edu • ENGR-11_Lec-09_Chp6_Manufacturing_Selection.ppt Transfer Molding Ram pressure Ram Heated mold Charge Engineering-11: Engineering Design 28 Sprue Part Bruce Mayer, PE BMayer@ChabotCollege.edu • ENGR-11_Lec-09_Chp6_Manufacturing_Selection.ppt Machining Processes Manufacturing Processes Deformation Extrusion Forging Rolling Bar drawing Wire drawing Casting Centrifugal Die casting Investment Permanent mold Sand casting Engineering-11: Engineering Design 29 Sheet Metal Bending Blanking Drawing Punching Shearing Spinning Polymer Processes Blow molding Casting Compression molding Extrusion Injection Molding Thermoforming Transfer molding Machining Finishing Boring Drilling Facing Grinding Milling Planing Turning Sawing ECM, EDM Anodizing Honing Painting Plating Polishing Bruce Mayer, PE BMayer@ChabotCollege.edu • ENGR-11_Lec-09_Chp6_Manufacturing_Selection.ppt Assembly Automated Bonding Brazing Manual Riveting Soldering Welding Machining Material Removal Sawing ≡ using a toothed blade. Milling ≡ form a flat surface by a rotating cutter tool. Planing ≡ using a translating cutter as workpiece feeds. Shaping ≡ form a translating workpiece using a stationary cutter. Boring ≡ increasing diameter of existing hole by rotating the workpiece. Drilling ≡ using a rotating bit forming a cylindrical hole. Reaming ≡ to refine the diameter of an existing hole. Turning ≡ form a rotating workpiece. Facing ≡ form turning workpiece using a radially fed tool. Grinding ≡ form a surface using an abrasive spinning wheel. Electric Discharge Machining ≡ by means of a spark. Engineering-11: Engineering Design 30 Bruce Mayer, PE BMayer@ChabotCollege.edu • ENGR-11_Lec-09_Chp6_Manufacturing_Selection.ppt Surface Finish Capability Engineering-11: Engineering Design 31 Bruce Mayer, PE BMayer@ChabotCollege.edu • ENGR-11_Lec-09_Chp6_Manufacturing_Selection.ppt Finishing Processes Manufacturing Processes Deformation Extrusion Forging Rolling Bar drawing Wire drawing Casting Centrifugal Die casting Investment Permanent mold Sand casting Engineering-11: Engineering Design 32 Sheet Metal Bending Blanking Drawing Punching Shearing Spinning Polymer Processes Blow molding Casting Compression molding Extrusion Injection Molding Thermoforming Transfer molding Machining Finishing Boring Drilling Facing Grinding Milling Planing Turning Sawing ECM, EDM Anodizing Honing Painting Plating Polishing Bruce Mayer, PE BMayer@ChabotCollege.edu • ENGR-11_Lec-09_Chp6_Manufacturing_Selection.ppt Assembly Automated Bonding Brazing Manual Riveting Soldering Welding Anodizing Engineering-11: Engineering Design 33 Bruce Mayer, PE BMayer@ChabotCollege.edu • ENGR-11_Lec-09_Chp6_Manufacturing_Selection.ppt Assembly Joining Manufacturing Processes Deformation Extrusion Forging Rolling Bar drawing Wire drawing Casting Centrifugal Die casting Investment Permanent mold Sand casting Engineering-11: Engineering Design 34 Sheet Metal Bending Blanking Drawing Punching Shearing Spinning Polymer Processes Blow molding Casting Compression molding Extrusion Injection Molding Thermoforming Transfer molding Machining Finishing Boring Drilling Facing Grinding Milling Planing Turning Sawing ECM, EDM Anodizing Honing Painting Plating Polishing Bruce Mayer, PE BMayer@ChabotCollege.edu • ENGR-11_Lec-09_Chp6_Manufacturing_Selection.ppt Assembly Automated Bonding Brazing Manual Riveting Soldering Welding Gas Shielded Arc Welding MIG (Metal Inert Gas) • a.k.a., Gas Metal Arc Welding (GMAW) • METAL Wire Electrode CONSUMED Engineering-11: Engineering Design 35 TIG (Tungsten Inert Gas) • a.k.a., Gas Tungsten Arc Welding (GTAW) • TUNGSTEN Electrode NOT Consumed Bruce Mayer, PE BMayer@ChabotCollege.edu • ENGR-11_Lec-09_Chp6_Manufacturing_Selection.ppt Matls & Manuf Compatibility Material Properties Manufacturing Processes Engineering-11: Engineering Design 36 COMPATIBLE materials & processes Bruce Mayer, PE BMayer@ChabotCollege.edu • ENGR-11_Lec-09_Chp6_Manufacturing_Selection.ppt Material-Process Compatibility thermosets sand casting investment casting die casting injection molding structural foam blow molding - extr blow molding - inj rotational molding Bulk Deformation impact extrusion cold heading closed die forging powder metal hot extrusion rotary swaging Metal Removal machined from stock ECM EDM Profile Generation Wire EDM Sheet Forming sheet metal bending thermoforming metal spinning © R. J. Eggert, BSU (Based on data from Boothroyd, Dewhurst & Knight) pg 47 Normal practice Less common Not applicable Engineering-11: Engineering Design revision Legend 37 Thermoplastics Refractory metals Nickel & alloys Titanium and alloys Magnesium & alloys Zinc & alloys Copper & alloys Aluminum & alloys Stainless Steel Alloy Steel Carbon Steel Materials Compatibility Cast Iron Processes Solidification Shape Attributes ME 488 Design for Manufacture & Assembly Bruce Mayer, PE BMayer@ChabotCollege.edu • ENGR-11_Lec-09_Chp6_Manufacturing_Selection.ppt 9/02/03 Manufacturing Costs Total Manufacturing Cost = Material + Tooling + Processing raw mat’ls molds fixtures jigs tool bits TMC Engineering-11: Engineering Design 38 = M +T labor electricity supplies O/H (deprec.) + P (6.1) Bruce Mayer, PE BMayer@ChabotCollege.edu • ENGR-11_Lec-09_Chp6_Manufacturing_Selection.ppt Material Cost per Part Let M = total materials costs (raw, bulk) q = production quantity Then material costs per part, cM is cM = M/q = (cost/weight x weight) / number of parts Let’s reorganize the variables in the equation above cM = [cost/weight] [weight/number of parts] = (cost/weight) (weight/part), and therefore cM = cost/part Engineering-11: Engineering Design 39 Bruce Mayer, PE BMayer@ChabotCollege.edu • ENGR-11_Lec-09_Chp6_Manufacturing_Selection.ppt Material Cost per Part (cont.) Let cw = material cost per unit weight, and wp = weight of finished part ww= weight of wasted material (the scrap) = Scrap-to-Useful Ratio → [wasted material weight]/[finished weight] = ww / wp Then the material cost per part, cM is cM = cw (wp + ww ) = cw (wp + wp ) (6.2) cM = cw wp (1+ ) (6.3) e.g. sand casting cM = ($1/lb)(1lb/part)(1+.05) = $1.05/part Engineering-11: Engineering Design 40 Bruce Mayer, PE BMayer@ChabotCollege.edu • ENGR-11_Lec-09_Chp6_Manufacturing_Selection.ppt Tooling Cost per Part Let T= total cost of molds, fixtures per production run q = number of parts per run Then cT= T/q (6.4) e.g. sand casting cT = ($10,000/run) / (5000 parts/run) = $2.00/part Engineering-11: Engineering Design 41 Bruce Mayer, PE BMayer@ChabotCollege.edu • ENGR-11_Lec-09_Chp6_Manufacturing_Selection.ppt Processing Cost per Part Let ct = cost per hour, (machine rate + labor) t = cycle time (hours per part) then cP = ct t (6.5) e.g. sand casting cP = ($30/hr) (0.3 hrs/part) = $9/part Engineering-11: Engineering Design 42 Bruce Mayer, PE BMayer@ChabotCollege.edu • ENGR-11_Lec-09_Chp6_Manufacturing_Selection.ppt TOTAL Cost per Part Cost per part, c= cM + c = cw wp (1+ ) + cT + cP T/q + ct t (6.6) e.g. sand casting c= $1.05 c= $12.05 / part Engineering-11: Engineering Design 43 + $2.00 + $9.00 Bruce Mayer, PE BMayer@ChabotCollege.edu • ENGR-11_Lec-09_Chp6_Manufacturing_Selection.ppt Example 5000 Part Run Mfg. Process Material Part weight (lb) alpha Material cost ($/lb), cw Tooling cost ($), T Production quantity, q Cycle time (hrs/part), t Machine rate ($/hr) Part cost ($/part) A Sand casting Aluminum alloy 1 0.05 1 10000 5000 0.3 30 12.05 Alternative B Injection molding ABS 3 0.01 0.25 35000 5000 0.03 100 10.7575 C Machining Bronze alloy 2 0.2 0.75 1500 5000 0.6 75 47.1 $45 of Bronze Part is due to Machining Engineering-11: Engineering Design 44 Bruce Mayer, PE BMayer@ChabotCollege.edu • ENGR-11_Lec-09_Chp6_Manufacturing_Selection.ppt Run Volume Sensitivity Cost ($/part) 1000 100 A ≡ Sand Casting B ≡ Inj. Molding 10 C ≡ Machining 1 0 1000 2000 3000 4000 5000 6000 Production quantity A Engineering-11: Engineering Design 45 B C Bruce Mayer, PE BMayer@ChabotCollege.edu • ENGR-11_Lec-09_Chp6_Manufacturing_Selection.ppt How to Lower Part Cost In Cost Eqn Minimize the SUM of Terms c = cw wp (1+ ) + T/q + ct t 1) 2) 3) 4) (6.6) purchase less expensive materials, keep our finished part weight low produce little manufactured waste (scrap, flash, etc.) design simple parts that require less expensive tooling 5) make many parts per production run (i.e., use large quantities between ReTooling) 6) choose a manufacturing process that has a low-cycle-time & low-cost-per-hour Engineering-11: Engineering Design 46 Bruce Mayer, PE BMayer@ChabotCollege.edu • ENGR-11_Lec-09_Chp6_Manufacturing_Selection.ppt All Done for Today Electro Chemical Machining Engineering-11: Engineering Design 47 Bruce Mayer, PE BMayer@ChabotCollege.edu • ENGR-11_Lec-09_Chp6_Manufacturing_Selection.ppt Engineering 11 Appendix Bruce Mayer, PE Registered Electrical & Mechanical Engineer BMayer@ChabotCollege.edu Engineering-11: Engineering Design 48 Bruce Mayer, PE BMayer@ChabotCollege.edu • ENGR-11_Lec-09_Chp6_Manufacturing_Selection.ppt ElectroPolishing Benefits of Electropolishing - Electropolishing produces a number of favorable changes in a metal part which are viewed as benefits to the buyer. All of these attributes translate into selling advantages depending upon the end use of the product. These include: • Brightening • Burr removal • Total passivation • Oxide and tarnish removal • Reduction in surface profile • Removal of surface occlusions • Increased corrosion resistance • Increased ratio of chromium to iron • Improved adhesion in subsequent plating • Reduced buffing and grinding costs • Removal of directional lines • Radiusing of sharp edges • Reduced surface friction • Stress relieved surface • Removal of hydrogen Electropolishing produces the most spectacular results on 300 series stainless steels. The resulting finish often appears bright, shiny, and comparable to the mirror finishes of "bright chrome" automotive parts. On 400 series stainless steels, the cosmetic appearance of the parts is less spectacular, but deburring, cleaning, and passivation are comparable. Engineering-11: Engineering Design 49 Bruce Mayer, PE BMayer@ChabotCollege.edu • ENGR-11_Lec-09_Chp6_Manufacturing_Selection.ppt ECM What is the Electrochemical Machining Process ? The process is based on Michael Faraday's Law of electrolysis, which is normally used in the electro plating of metals. Electrochemical machining is the reverse of plating, the work-piece is made the anode, which is placed in close proximity to an electrode (cathode), and a highamperage direct current is passed between them through an electrolyte, such as salt water, flowing in the anode-cathode gap. Metal is removed by anodic dissolution and is carried away in the form of a hydroxide in the electrolyte for recycling or recovery. A major advantage of electrochemical machining is that it can be used as a de burring or machining process on any metal, no matter how hard or corrosion resistant it is, without creating any residual thermal or mechanical stress in the work-piece. The ECD process produces smooth, burr free edges and ECF can produce smooth, three dimensional forms with a good surface finish in single plunge forming pass. The process is simple to operate and offers fast production rates for difficult to conventionally machine alloys, with low running and tooling costs. ECM does not create any physical or thermal stress during machining and components may be machined either before or after heat treatment. Metal removal rates are approximately 60 cubic mm per minute per 1000 amperes DC current employed. Surface finish may be less than 0.4 microns for some materials. Otherwise difficult to conventionally machine alloys can be easily machined or de-burred by ECM. Examples include the stainless steels, high performance and high temperature alloys such as Inconel, Rene, Hastelloy, Titanium, Waspalloy and the latest generation corrosion resistant nickel alloys such as 617 and Alloy 59. Engineering-11: Engineering Design 50 Bruce Mayer, PE BMayer@ChabotCollege.edu • ENGR-11_Lec-09_Chp6_Manufacturing_Selection.ppt