Mfg Processes & Engr
Mfg Processes & Engr ME 4210
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This 0 page Class Notes was uploaded by Chloe Reilly on Monday November 2, 2015. The Class Notes belongs to ME 4210 at Georgia Institute of Technology - Main Campus taught by Jonathan Colton in Fall. Since its upload, it has received 25 views. For similar materials see /class/234228/me-4210-georgia-institute-of-technology-main-campus in Mechanical Engineering at Georgia Institute of Technology - Main Campus.
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Date Created: 11/02/15
39 3972quot V w 0W W La v 4 39 1 QQ CJ Z V kawmzfy ygm 1 V V MM awxm WWM Wm q Wi 7f kffjj7fif j I a J r T 12 W1H ampk uw MK J vxocemx ai fb V a H is w a EWK 7 1 A I 4 I i f fwf g Q g 5 macaw M 7 AS j3 mix ca Lk 0 V 1 awe I tqu TEwltrwqg Mlk s MLch Mcncgifmow 4 V l a quot f xf 77 3 39 a U j o ERRATA August 3 1999 J Tlusty Manufacturing Processes and Equipment The following corrections are to be entered in the Problem sections of several chapters The correct versions of the passages to be changed are put in brackets and underlined L1 P63 Flow through round channel In a way analogous to Figs 611 612 613 write a Matlab computer program and produce plots of velocity distribution and of strain rate distribution for a Newtonian uid with viscosity 100 Pas at strain rate of 3000 sec and b NonNewtonian uid with viscosity characterized by parameters Kl2l98 and n04 see Egs 639 640 and 647 for ow in a round channel with R2mm length L50mm and pressure drop AP 30 MPa Plot u and gammadot versus r P74 P75 A milling operation is being performed similar to the one shown in Fig 730 The feedtooth c 02 mm a 300 and the start and end angles are 1 30quot and 12 1600 a Determine the mean chip thickness hm17 b Indicate in a graph of h vs 1 the variation of h on one tooth over two revolutions of the cutter Graphically express the variation of torque in an end mill In a graph of torque vs angle 1 plot the torque of three subsequent teeth and nd the maximum total torque on the end mill The cutter has 8 straight teeth and a diameter of 100 mm The workpiece engages the cutter from 1 450 to 12 1500 and the axial depth of cut an 20 mm Chip load is c 02 mm Assume a speci c force ofK 2000 Nmmz A 4 uted end mill of 40 mm diameter is performing an upmilling operation as shown in Fig 729a into a workpiece of 1035 steel The axial depth of cut aa 20 mm and the radial depth of cut ar 25 mm The cutting velocity v 45 mmin with a feed g tooth ofg 025 mm Determine a Spindle speed 71 revmin b Feed rate f mmmin c Metal removal rate Q cm3min d Mean chip thickness hm mm e Speci c power KS Wcm3 min from Table 71 f Power P kW P77 A face milling operation is being performed similar to that of Fig 730 A 300 mm diameter cutter with 16 teeth is cutting a 200 mm wide strip of 1035 material which is centrally located under the cutter axis The operating parameters are an 5 mm v l50 mmin and c 025 mm Determine a Spindle speed 71 revmin b Feed rate f mmmin c Metal removal rate Q cm3min d Mean chip thicknesshEJmm e Speci c power KS Wcm3sec f Power P kW P810 Investigate machining Ti alloys with a high rake angle thin chips and high cutting speed Refer to Fig P8 10 a Take the case of Example 84 with v 05 msec h 02 mm a 00 B 220 1 230 b 10 mm as reference a In order to properly include the effect of change of the rake angle and the corresponding changes of the shear angle 1 and of the length LC of the shear plane the cutting force F will be derived from the shearing force F 5 which itself is obtained from the shear ow stress 15 F 5 rs L b From this the value of the friction force F f is further derived Refer to Fig88 and Eq8 13 b First change the rake angle to a 120 This will affect also the other angles of the cut in the way that has been discussed and expressed in Eq8 l3 Assume friction angle 4 220 39 this results in E 100 and 1 350 Assume LC 4h1 c Add the next change h 005 mm d Now see if you could afford to triple the speed to v l5 mmsec and still keep the peak temperature within acceptable limits Plot lek lKK versus x for all the four cases in one plot P812 Power MRR cost in atuming operation Refer to Fig P8ll Mean diameter dm 75mm length L 200 mm depth of cut a 5 mm feed per revolution fr 025 mm Specific force K 2000 Nmmz cutting speed v l50 mmin Tool life eq v3fr2T 8 x 106 vmmin mm Tmin C1001 edge 40 tmol Change 8 min machine rate r 04min Determine the power consumed kW machining time rm cost per part Cp P813 Optimum speeds feeds cost Use Fig R811 A single tool single pass turning operation has a tool life equationv3395fr2395T l524x106 v mmin fr mm T min The rate for using the machine is m 05min the tool changing time is tmh 5 min and the cost per tool edge is Cm 250 6180 mm L 400 mm a The feed rate is limited by the maximum permissible cutting force of F max 2516 N If the cutting force is determined by F l400bfr 1 and b 5 mm what is the maximum feed rate b Express the machining time rm as a function of v and determine the optimum cutting speed vop mmin c What is the corresponding machining time rm and the minimum cost per part C P Replace Fig P95 As shown here the letter A has been added Replace Fig P97 As shown here the number of teeth on the cutter should be 4 not 6 a Upmilling b Downmilling g amp d2inm a5mm j P914 Chatter in milling Modify the case illustrated in Fig964 Instead of slotting assume a Upmilling with radial immersion ad 025 b Down milling with ad 025 Number ofteeth is m 4 Comment for the correction now go over to paragraph 2 2 Modify the program listed in Fig 965 to accommodate the different radial immersionsm the fact that onl one tooth is cuttin at atime and run simulations for b 05 b and b 18 bLm Use spindle speedN 3 000 rpm andM 2560 quot steps Plot x y nyFy a5mm A d25mm P106 line 4 of the task speci cation the SDM system parameters are k 25 e 7 Nm the letter M is replaced by m meters Replace Fig P111 As shown here the letter kg is replaced by kg P1111 Finite Difference computation of a thermal field of a weld This task is analogous to Example 1111 The size of the eld is different as is also the way of presenting the results The size of the field is given by i 120 j 1150 The transformed independent variable Thas the dimension n 13000 It is Ax 3 mm Ay 3 mm g 45 mm The arc is in location n 2001 The welded material is steel with parameters k 43 Nsec C a 12 mm2 sec pc 37N C mmz a The starting parameters are power inputP 800 W welding speed v 2 mmsec Calculate the final temperature Tf Write the computer program to compute the 3000 values of T and plot a graph of temperature profiles along lines parallel with the weld line those in rows i 1 2 3 10 20 Use enmax 2 0C Determine the number of iterations k Read the maximum temperature T2001 Plot all five lines in one graph versus distance x b Change inputP so as to obtain T2001 1490 0C with the same welding speed and obtain new plots What is the value of the new P c Increase the speed to v 4 mmsec and run the computation with the original value of P Obtain new plots read maximum temperature T2001 Attach the three graphs P1112 Residual stresses see Fig P 1112 Carry out an exercise like those in Sec 119 but assume different gradients of temperature in the direction away from the weld line as shown in the models at a and b Use yield strength Y 300 Nmm2 and for simplicity keep it constant independent of temperature thermal expansion coef cients 0 1e 5 C and modulus of elasticity E 2e5 Nmm2 Plot graphs like those in Fig 11105 and determine temperatures T1 and T2 at which first the middle bar and then the outer bar become plastic Determine the residual stresses cm of 00 There are also corrections for the text of the book Page 116 Table 31 Fig iron r quot39 The heading ofthe last column should be C instead of Fe Page 56 Eq 212 should read Y 07 k D39 0395 the exponent is negative Page 656 Eq1043 should be to 7rud x is replaced by 7r Page 813 the equation that follows Eq 1180 and the words modifying and acknowledging that AxAy should read Ti Lj iTijI f j1 lj Pgk Ti11 quotTM 4 the signs of the subscript of the second term and of the fth term in the parentheses of the left hand side are to be changed Page 814 the top line in the expression B Axva the capital letterB replaces b Page 846 the paragraph between Eq 1215 and Eq 1216 the value of c is 418 Nmg gOC and not 418 In Eq 1217 in the denominator instead of R e 025 025 it should be written Re 544 A CHAPTER 9 Design of Machine Tools Drives and Structures marked at the t 0 axis in the graph and show the three de ection components that determine the error of location of the machined surface The surface 5 is overcut by 2375 mm 39 A EXAMPLE 98 Slotting with a TwoFluted Cutter Nonresonant Conditions V Assume the same natural frequency of the system f speed n 8400 rpm 140 revsec the tooth freque cy is f odic force is exciting the system below resonance z and the spindle Hz the peri Axial depth of cut b 10 mm Speci c force K 1000 Nmm Chip load c 01 mm Stiffness on the tool k 1000 Nmm The components of the cutting force Fy are expressed in the same way as in Example 97 except for the frequency Fyl 500 cos 27139 X 280 t N F 150 sin 27 X 280 t N 39DC 500 N and the force graph is the same as Fig 938a except for the time scale The phase shift of the vibration behind the forces is obtained using Eq 941 2 p 4gt atan2 1 p2 where p ffn Thus 280 p m 09032 9b and the ratio of the vibration amplitude A to the force amplitude is obtained from Eq942as llk0 27 00051 F V 1 pf2 4572 Thus we obtain 1 mm and A2 m The forces and vibration components are shown in Fig 939 where they are represented by rotating vectors the projection of which onto the real axis deter mines the instantaneous values At time t 0 a positive cosine function is on the positive real axis and a positive sine function is on the negative imaginary axis Thus F 1 negative cosine is on the negative real axis and Y1 is 3 6439sin3 11 W and the error 6 is obtained as w MeiEAng ff u rj 56x m5JaTtamp aquot a dif vg a mi AL kc f vza39 0 VAr JAN M Z W z f Z 7amp9 Wxgg2x 5 Mg Mgr ma T 3901 MM 0 gt 22 3 a 0 am 9 735 We 33 m Cawjyuwar 0 wt S ANVL Cag u w a EM we QQ LH Q j p 724 5 O b mgru m wQ K BA 9mm quot4amp5 l v w amp 9 mam 2 4e Wm 43m ramm W W Qtsz J4 6 966ng C digEm M AHQL CERT A0 4O 414quot so 3 20 x 4 H03 v 3 V aw 3g W No L 7 7 Sac no0 auemag th twg L s tv m Woz QUMg Addie 7J5 r EOIUW d amp gt MS UQUquotWL Awagka 39 t S w 7W 541 z VAAC Z m 3 Pkg m 03 Lwwgtw AL 2 wxw xs 5 New A a u MWUIJ INC 71 62 nambv 36509 52303 z oati il 202300 91100 gtlt vx 4W0quot lag5 M03 r 5264 MB 50 14 Ag pwk lugJ m 6 6 7 5 23 mpg z w 4 2M ws 6v e 51246 My 4 WWW aky m came PEWS if We wo laud 7 gnarlLS as P05194754 m ou cvoinm v v w Wv 4 MicroMachining GQorgiaDE EEE g ME 4210 Manufacturing Processes amp Engineering 1Te hm gy Prof JS Colton Micromachining Photolithography Etching LIGA LaserAblation Mechanical Micromachining GQorgia mg gg ME 4210 Manufacturing Processes amp Engineering 1Techm gy Prof JS Colton Micromachining Basics Refers to techniques for fabrication of 3D structures on the micrometer scale Applications include MEMS devices eg airbag sensor medical devices microdies and molds etc Most methods use silicon as substrate material Georgia mgs gj ME 4210 Manufacturing Processes amp Engineering frTechmobgy Prof JS Colton Photolithography Resisi Used in xvii microelectronics a UViight source fabrication S k Mask Used to pattern oxidenitridepolysiicon WWW WieResis films on silicon b substrate Ema Basic steps um g photoresistdevelopment C v Etching v Resist removal Georgia m m ME 4210 Manufacturing Processes amp Engineering 4 fFTechm Prof JS Colton Photolithography Process Description The wafers are chemically cleaned to remove particulate matter organic ionic and metallic impurities Highspeed centrifugal whirling of silicon wafers known as quotSpin Coatingquot produces a thin uniform layer of photoresist a light sensitive polymer on the wafers Photoresist is exposed to a set of lights through a mask often made of quartz Wavelength of light ranges from 300500 nm UV and Xrays wavelengths 450 Angstroms Two types of photoresist are used Positive whatever shows goes Negative whatever shows stays EXPOSURE RADIATION I l l I I I I I I NEGATIVE RESIST lb POSITIVE RESIST a Resist exposure characteristics In Resist after development Georgia mgj ii n Va ME 4210 Manufacturing Processes amp Engineering 5 TechLIebq Prof JS Colton Etching Vwammabove Process Variations m 1 Wet etching 547quot 2 etCh I ng Cross section Hquot Huh 335k amp Slow etching crystal plane Etch mask 7 non Anisotropic Isotropic Variations of wet etching Georgia m gg ME 4210 Manufacturing Processes amp Engineering TechLi g Prof JS Colton Wet Etching Process Description The wet etching process involves Transport of reactants to the surface Surface reaction Transport of products from surfaces The key ingredients are Oxidizer eg H202 HNO3 Acid or base to dissolve the oxidized surface eg H2804 NH4OH Dilutent media to transport the products through eg H20 Georgia mgs gj ME 4210 Manufacturing Processes amp Engineering ffTechmebgy Prof JS Colton Dry Etching Writs i iigulit39or r tr f quot K 397 Upper electrode I Lower electrode Process Variations Waferhower 1 Plasma based 2 Non plasma based Diffuser nossles l Gas Pump Gas A typical parallel plate plasma etching Georgia mlg m ME 4210 Manufacturing Processes amp Engineering 8 fFTechU lJ Prof JS Colton Bulk Micromachining Process for producing 3D MEMS structures older process Uses anisotropic etching of single crystal silicon Example silicon cantilever beam for atomic force microscope Georgia mgs gj ME 4210 Manufacturing Processes amp Engineering fiTechmobgy Prof JS Colton Bulk Micromachining a Di usedlayu39 egPWPG Si Dopant DifquIon b one mgmask eg silicon nitride Masking a Fmgstauding Anisotropic Etching Georgia g ME 4210 Manufacturing Processes amp Engineering 10 Techm Prof JS Colton Surface Micromachining Newer process for producing MEMS structures Uses etching techniques to pattern micro scale structures from polycrystalline poly silicon or metal alloys Examples accelerometers pressure sensors micro gears and transmissions micro mirrors etc Georgia mgs gj ME 4210 Manufacturing Processes amp Engineering 11 fiTechmebgy Prof JS Colton Surface Micromachining c b a Phosphosilicateglass sp ayer a deposition of a phosphosilicate glass PSG spacer later b etching of the spacer layer C deposition of polysilicon d etching of polysilicon e selective wet etching of PSG leaving the silicon substrate and deposited polysilicon unaffected Georgia mg m ME 4210 Manufacturing Processes amp Engineering 12 Techrm ii gjy Prof JS Colton Comb Drives and Gears I quot 2 Spider Mites on Ring slow Spider Mite on Ring faster ME 4210 Manufacturing Processes amp Engineering Georgia ms i u e Prof JS Colton Techmebgj Typical MEMS Parts Six gear chain Georgia mg ME 4210 Manufacturing Processes amp Engineering 14 Techm Prof JS Colton Typical MEMS Parts Silicon mirror assembly Georgia g im e Techm ii ME 4210 Manufacturing Processes amp Engineering Prof JS Colton Typical MEMS Parts Motor Georgia ng ME 4210 Manufacturing Processes amp Engineering 16 39Techm Prof JS Colton LIGA German Acronym chographie Lithography Qalvanoformung Electroforming A bformung Molding 1 Lithography 2 Elactroformlng Irrdlotlnn Wm M mewi im Mn v I r I Divalupmlm mumquot quotIMO I 51 III Wm armva uid Inlg i 7 3 Mnldlng 4 Ceramic Fabrlcatlun any cumin siurry WW 5quotquot culinl Mm 39 mm 39 W Georgia img m ME 4210 Manufacturing Processes amp Engineering Techm Prof JS Colton LIGA Basic Steps Mask membrane Absorber structure PMIMA Resist Subsnaw Developing PMMA Structure Elech oform mg b Xray Imion Mold cavity Mold lling Plastic Electrically conduct substrate Resrst Developme Mold removal Plastic structure as mo 01 final product Elect roforml n Metal from electro 3914 r ceram from slip casting electmfmming Resrst Removal Metalorceram39rc Fmal product Mold insert Final Pmducl mane Georgia g m eg ME 4210 Manufacturing Processes amp Engineering 18 Techm gjy Prof JS Colton LIGA Process Description Deep Xray lithography and mask technology Deep Xray 001 1nm wavelength lithography can produce high aspect ratios 1 mm high and a lateral resolution of 02 pm Xrays break chemical bonds in the resist exposed resist is dissolved using wetetching process Electroforming The spaces generated by the removal ofthe irradiated plastic material are filled with metal eg Ni using electrodeposition process Precision grinding with diamond slurrybased metal plate used to remove substrate layermetal layer Resist Removal PMMA resist exposed to Xray and removed by exposure to oxygen plasma or through wetetching Plastic Molding Metal mold from LIGA used for injection molding of MEMS structures Georgia ms M m Techmo ME 4210 Manufacturing Processes amp Engineering Prof JS Colton LIGA Process Capability High aspect ratio structures 1050 Max height 1500 um Surface roughness lt 50 nm High accuracy lt 1pm Resis structure of refiediuri nralirm 025 um hei h125 um shuctuml height H g h a Bar struclure 43VVLHEH with parallel High aspect ratio Georgia mgs g ME 4210 Manufacturing Processes amp Engineering 20 Techm H giy Prof JS Colton Laser Ablation LONG PULSE ALASER BEAM EIECTED MoLTEN MAI RIAL DANAGE GUJSED m E SURFACE DEBRIS ADJACENT SIRUCTURES RECAST LAYER SURFACE RIPPLES DUE TO SHOCK WAX E IRAN Fr R m BLIRROUNDINB MATERIAL Georgia m m ME 4210 Manufacturing Processes amp Engineering 21 fFTechm Prof JS Colton Laser Ablation Process Description Highpower laser pulses are used to evaporate matter from a target surface A supersonicjet of particles plume is ejected normal to the target surface which condenses on substrate opposite to target The ablation process takes place in a vacuum chamber either in vacuum or in the presence of some background gas Georgia mgs gj ME 4210 Manufacturing Processes amp Engineering 22 Techmobgy Prof JS Colton Mechanical Micromachining Lithography andor etching methods not capable of making true 3D structures eg free form surfaces Also limited in range of materials Mechanical machining is capable of making free form surfaces in wide range of materials Can we scale conventionalnontraditional machining processes down to the micron level Yes ME 4210 Manufacturing Processes amp Engineering 23 Georgia mss iiw e Prof JS Colton Techmebgy Mechanical Micromachining Two approaches used to machine micron and submicron scale features Design ultra precision nanometer positioning resolution machine tools and cutting tools Ultra precision diamond turning machines Design miniature but precise machine tools Microlathe micromill microEDM etc GQorgia mg gg ME 4210 Manufacturing Processes amp Engineering Techmebgy P 24 ref JS Colton Ultra Precision Machine Tools Y spin Z X Mold for sphericaspheric lenses Source wwwtoshibamachinecom Georgia m m ME 4210 Manufacturing Processes amp Engineering 25 Techm lJ Prof JS Colton Miniature Machine Tools 4 Micro Lathe Source MEL AIST Japan Georgia mg w ME 4210 Manufacturing Processes amp Engineering 26 Techm1 U gjy Prof JS Colton Miniature Machine Tools Micro Turning Micro Milling Source MEL AIST Japan Georgia mg nm ME 4210 Manufacturing Processes amp Engineering 27 TechUi y Prof JS Colton cro Cutting Tools Cutting tools made by Focused Ion Beam FIB machining 10 um A 25 1m end mill fool right with ve curring ricated using focused Ion beam machin mg The end ml was used to make his 25pm wide x 25pin deep channel 5 above In aluminum Source httpwwwsandiagov Source Adams et al Prec Eng 24 2000 347356 Georgia g m eg ME 4210 Manufacturing Processes amp Engineering 28 frTechUt jy Prof JS Colton Micro Cutting Tool 10 um tool with human hair Georgia mg ME 4210 Manufacturing Processes amp Engineering 29 Techm Prof JS Colton Micro Injection Molds Microcantilever Cavity Base Part Cavity Georgia Dmg i w e Techm D y Microcantilever 330 micron Microcantilever Base Part Tweezer Arm ME 4210 Manufacturing Processes amp Engineering Prof JS Colton 30 Stencil Machining 1 50 gm N 50000 rpm feed 100 mmmin chip size 100 nm Georgia mg m ME 4210 Manufacturing Processes amp Engineering 31 Techm ily Prof JS Colton Mechanical Micromachining Process Description Can produce extremely smooth precise high resolution true 3D structures Expensive nonparallel but handles much larger substrates Precision cutting on lathes produces miniature screws etc with 12 um accuracy Relative tolerances are typically 110 to 11000 of feature Absolute tolerances are typically similar to those for conventional precision machining micrometer to submicrometer Georgia mgs gg ME 4210 Manufacturing Processes amp Engineering 32 Techmobgy Prof JS Colton Summary Micromachining methods IC fabrication based processes Mechanical machining based processes Applications in MEMS medical device fabrication etc Still evolving field Georgia mgs gj ME 4210 Manufacturing Processes amp Engineering 33 ffTechmebgy Prof JS Colton