Indirekte Fabrikation af Lattice Metals med tyndslib Brug Centrifugal Casting
Summary
En indirekte additiv fremstillingsmetode kombinere en 3D-printning af polymerer med en centrifugal casting er skitseret for fremstilling 3D Oktet truss metaller (Al og Cu legeringer) med en enhedscelle længde på 5 mm med en vægtykkelse på 0,5 mm.
Abstract
En af de typiske metoder til at fremstille 3D-gitter metaller er den direkte metal fremstillingsvirksomhed (AM) proces additiv såsom Selective Laser Melting (SLM) og Electron Beam Melting (EBM). På trods af sin potentielle behandlingsevne, direkte AM metode har adskillige ulemper, såsom høje omkostninger, dårlig overfladefinish på slutprodukter, begrænsning i materialevalg, høj termisk belastning, og anisotropiske egenskaber dele. Vi foreslår en omkostningseffektiv metode til at fremstille 3D-gitter metaller. Formålet med denne undersøgelse er at tilvejebringe en detaljeret protokol om fremstilling af 3D lattice metaller med en kompleks form og en tynd vægtykkelse, fx Oktet truss fremstillet af Al og Cu legeringer med en enhedscelle længde på 5 mm og en cellevæg tykkelse på 0,5 mm. En samlet eksperimentelle procedure er opdelt i otte sektioner: (a) 3D-print af offer mønstre (b) smelte-out af support materialer (c) fjernelse af rester af support materialer (d) mønster assembly (e) investeringer (f) udbrændthed af offer mønstre (g) centrifugal støbning (h) efterbehandling for slutprodukter. Den foreslåede indirekte AM teknik giver mulighed for at fremstille ultra-letvægts gittermaster metaller. F.eks gitterkonstruktioner med Al-legeringer. Det fremgår, at procesparametre skal kontrolleres korrekt, afhængigt af materialer og gitter geometri, observere de endelige produkter af oktet truss metaller ved den indirekte AM teknik.
Introduction
Cellular metaller er metaller, der består af et sammenhængende netværk af faste stivere eller plader og har komplekse mikro-arkitekturer med hulrum 1. Som eksempler kan nævnes både i) tilfældigt strukturerede stokastiske skum og ii) periodisk bestilt todimensionale (2D) honningtavler og tredimensionale (3D) gitter truss strukturer. De har fået opmærksomhed på grund af deres høje specifikke stivhed og styrke 1-3 og høj specifik modstandsdygtighed 4-5, fremragende energi absorption for virkningen lastning 6, lydisolering 7, mulig udformning af varme dissipaters og varmevekslere 8. Især, periodisk ordnede gitterstrukturer har potentiale til at konstruere de egenskaber, overlegen med en evne til at styre interne porøse netværk geometri.
På grund af deres komplekse interne porøse netværk geometri, er det vanskeligt at fremstille cellulære metaller anvendelse af den konventionelle subtraktive machining. Som sådan, forskere er begyndt på udkig efter alternative metoder til at fremstille cellulære metaller: danne gas i flydende metal eller blanding metalpulver med blæsemidler blev udforsket til fremstilling stokastiske metal formularer 9. På grund af den manglende kontrol med celle topologi, er det svært at skræddersy mekaniske egenskaber. Alternativt blev fremstillingsmetoder til periodisk bestilt cellulære metaller udforsket: stempling tynde plader af metal ind i en bølget form efterfulgt af forbinde dem til at skabe periodiske strukturer 10, limning slidsede metalplader 11, ekstrudering 12, vævning og flammende metal filamenter at fabrikere tekstiler 13. Selv om disse fremstillingsmetoder tilbyde gentagelige mønstre, er mønstrene stadig begrænset i den plane retning. I et forsøg på at generere 3D mønster gentagelse, forskerne begyndte at bruge additiv produktion (AM), f.eks Selective Laser Melting (SLM) 14, Electron Beam Melting (EBM) <sup> 15, og Direkte Metal Laser sintring (DML) 16. På trods af deres evne til at fremstille 3D bestilt komplekse gitter geometrier, der stadig eksisterer nogle begrænsninger: problemer med at bruge metaller med høj varmeledningsevne og høj optisk refleksivitet 17, høj termisk resterende stress 18, dårlig overfladefinish med "Balling" fænomen under laser eller elektron smeltning 19, anisotrope egenskaber 20-21 af dele som følge af en kombineret effekt af den lagdelte produktion, anisotropisk dannelse af korn, pulver størrelse, magt og scanning hastighed laser eller elektronstråle 15, stort energiforbrug, osv.
Kombinere polymer baseret AM med metal støbning kan tilvejebringe en alternativ metode til at fremstille gitter metaller. Man kan kalde dette "indirekte AM". Indirekte AM kan en løsning at overvinde de tekniske problemer med direkte AM af metaller, der er nævnt ovenfor. Adskillige indsats har været made at fremstille gittermaster metaller ved hjælp indirekte AM kombinerer 3D-print af polymerer med tyngdekraften baseret støbning 22-25, fx en investering støbning kombineret med smeltet deposition modellering (FDM) for at fremstille et gitter legering 22-25 eller sandstøbning kombineret med en sand pulver baseret AM 23. Den tyngdekraft baseret casting synes at forblive en teknisk udfordring at overvinde – misrun og porøsitet forårsaget af pludselige størkning af smeltede metaller, når de mødes netværksstrukturer med skarpe hjørner af gitter strukturelle forme 25-26. Relativt store overfladeareal af lattice strukturelle forme synes også at bidrage til pludselig afkøling, hvilket resulterer i for tidlig størkning 25-26.
I denne undersøgelse foreslår vi en alternativ indirekte AM, der kan overvinde misrun under fremstilling af lattice metaller – centrifugal casting til et gitter formhulhed foretaget af en 3D trykt gitter offer polymer mønster. Vi bruger en digitallys behandling (DLP) baseret 3D-print metode til at opbygge et gitter strukturel offer mønster efterfulgt af centrifugal støbning af Al og Cu-legeringer. Formålet med denne undersøgelse er at give en detaljeret protokol om fremstilling af 3D-gitter metaller med en kompleks form og en tynd vægtykkelse. Det vigtigste bidrag i denne proces er at give mulighed for at udvide valg af materialer med lave omkostninger produktion til fremstilling gitter metaller.
Protocol
Representative Results
Discussion
For konventionel metal støbning, er det vigtigt at holde det smeltede metal flow glat og strømlinet i "laminar 'i formhulrummet og hellere undgå uregelmæssige og ophidsede flow generelt observeret i turbulent strømning 27. Det er derfor vigtigt at tilrettelægge indløbet af sprue system er forbundet med rotationshastigheden af en centrifugal arm for at opretholde strømmen af smeltet metal inden i gitter formhulrummet 'laminar «.
I denne undersøgel…
Disclosures
The authors have nothing to disclose.
Acknowledgements
Denne undersøgelse modtaget støtte fra Research Indledning Grant (RIG) i Vice President for forskning og økonomisk udvikling ved University of North Texas (UNT). Forfatterne også takke KCIS Co. Ltd for delvist at støtte denne undersøgelse. Støtten fra PACCAR Teknologi Institut på UNT for succes i denne publikation er meget værdsat.
Materials
| Motorized centrifugal casting machine | Rey Motorized Centrifugal Casting Machine, Rey Industries Inc. | Made in U.S.A. by Rey industries, Inc. Dallas, TX 75220 | |
| Gypsum powder | Satin Cast 20, FindingKing Kerr | 7960 | Gypsum powder is used to make the investment mixture |
| Ployjet 3D printer | Projet HD3500 Plus, 3D Systems | This polymer based 3D printer to print out sacrificial pattern for casting. | |
| Cartridge materials – UV curable and castable acrylic plastic | VisiJet Procast, 3D Systems | This is castable material that is going to be burn out before casting | |
| Cartridge materials- support material | VijiJet S300, 3D Systems | This is support material that is going to be removed before pattern assemble | |
| Ancient Bronze Casting Grain | Rio Grande | 706051 | This true bronze grain contains no zinc. Highly fluid, it melts quickly, casts cleanly and provides a good balance between strength and durability. The warm, deep-bronze color has rich red undertones, and the alloy takes a good patina. Composition is 90% copper with an amount of tin; fits into the CDA#90700 category. This grain is sold in 1-lb. packages. |
| Aluminum Round Wire, 1/8", 1-Lb. Spool, Dead Soft | Rio Grande | 134700 | Lightweight and strong, aluminum wire is an economical and versatile choice. Not as bright-white as silver, aluminum offers a warmer tone much like that of platinum. Solder ONLY with low-temp solders such as Stay-Brite; suitable for both pulse-arc and laser welding. This quality aluminum wire is packaged on 1-lb. spools. |
| Computer aided design software (Pro-e) | This software can be replaced with the others such as Auto CAD, Catia, and so on. | ||
| ProJet Finisher 1-A | 3D Systems | This machine is used to melt the support material. | |
| 160 Watt 2.5 Liters Digital Ultrasonic Cleaner with Timer Heater Rings Tools | Chicago, Electric, Power Tools | 85 oz. capacity, Five cleaning cycles: 90, 180, 280, 380 and 480 seconds, Clean with or without heat, Easy-to-read LED digital timer, Clear-view window | |
| Fan | Honeywell Inc. | HT-800 | 120V A.C., 60Hz., 0.85A. TP |
| Paraffin wax for wax sheet – Modeler's Pink Wax Sheet, 3" by 6", 24-Ga. | Rio Grande | 700075 | Sheet wax is flexible and can be cut or formed into any shape. It’s ideal for designing since you can draw or trace directly onto the sheet; choose green or pink depending on which will best show your designs. High manufacturing standards ensure exceptional consistency and significant price savings. Value is enhanced by larger package quantities at the same price as the smaller packages available elsewhere. Each 8-oz. package contains approximately 30 sheets. |
| Paraffin wax for wax stick – Modeler's Medium Red Sprue Wax, 8-Ga | Rio Grande | 700741 | A pliable, softer sprue wax than the firm blue. Good for forming gates and sprues and burns out cleanly with no residue. |
| Alcohol Lamp | Rio Grande | 700008 | Use this lamp to heat wax-working tools or as a flame polisher. The heavy glass reservoir has faceted sides to allow it to be tipped for angling the flame. A screw adjustment for the 7" x 3/16" wick controls the height of the flame. A safety cap snuffs the flame and prevents fuel evaporation. For the best flame, use methyl alcohol fuel. Replacement wicks available. Reservoir holds 5 oz. (150ml) of fuel. |
| Wax carving tool set – Soft Grip Wax Carvers, Set of 10 | Rio Grande | 700329 | This boxed set offers the best in cutting and shaping technology. Each of these ten high-quality steel wax-carving tools features a 5/16" PVC covered handle that ensures a sure, comfortable grip through hours of work and all have sharp edges for shaping and fine detailing. Sharpen or custom-shape each tool to fit your needs. These tools provide exceptional tool strength and deliver excellent results. This set comes in a hinged, foam-lined wood box. |
| Rubber Mixing Bowl, 1-1/2 Qt. | Rio Grande | 702131 | This highly-flexible vulcanized rubber bowl is easy to grip, will not be marred by a spatula and cleans with ease. |
| Pyrex Beaker, 1,000ml | Rio Grande | 335040 | Ideal for holding and heating bath plating solutions, this genuine Pyrex glass beaker is sturdy and durable. |
| Rio Premium Stainless Steel Flask, 2-1/2" dia. | Rio Grande | 70201514 | This solid, #304-quality stainless steel flask is corrosion-resistant, durable for a long service life and performs under extreme temperature without distortion. |
| CAST/T Ceramic Casting Crucible, 450g | Rio Grande | 705047 | Made exclusively for the CAST/T centrifugal casting machine, this crucible is designed with an angled base that slides into the hinged bracket on top of the casting machine. This brings the crucible into perfect alignment with the center of the flask ring to ensure an error-free pour. |
| MyWeigh iBalance 300 Digital Scale | Rio Grande | 116850 | This scale is used to measure the weight of the sacrificial and sprue system for metal which is going to be used for centrifugal casting. |
| Rubber bottom – CAST/T Flask Ring Base | Rio Grande | 705025 | Specially made for the CAST/T centrifugal casting machine, this rubber base accommodates all Table King flask ring styles, creating a secure, airtight seal throughout the investment process. The center post fits either of the wax disc styles for complete versatility. |
| Scotch® Colored Duct Tape, 1 7/8" x 20 Yd., Blue | OfficeMax | 22353766 | This scotch tape is used to make sure that the gypsum-water mixture fully covers the assembled sacrificial pattern inside the flask by allowing for extra material above the flask height |
| Vacuum casting machine – V.I.C. 12 Tabletop Solid- and Perforated-Flask Casting Machine with The Rio Assistant, 110-Volt | Rio Grande | 70511814 | The V.I.C. 12 casting machine offers all the latest technical innovations for efficient, productive vacuum investing and casting. Designed to meet the demands of medium-sized casting operations, this machine includes a powerful 1/2hp, 5cfm vacuum pump for effective vacuuming and outstanding casting results. The V.I.C. 12 casts small or large flasks. Includes an adapter table that accepts standard solid flasks up to 5" x 7" high and is mounted on rubber feet for stability. |
| Furnace for burn out sacrificial pattern -Rio Model 1000 Enameling Kiln with Nine Program Controller | Rio Grande | 703121 | The Rio enameling kiln features three pre-set firing temperatures for enamels and six that you can define. Use the exclusive Rio controller to set and maintain firing temperatures. Perfect for all types of enameling, including tall pieces. Includes ample space for firing and an easy-latch door that will not jar your enamels when opening and closing. Also suitable for metal clay, glass and ceramics. Galvanized steel case with high-temperature insulating firebrick keeps them cool. Element protected in recessed groove. Includes user instructions. |
| Smith Complete Little Torch Acetylene and Oxygen System | Rio Grande | 500030 | Get everything you need to equip your shop for soldering and brazing. Use Little Torch systems for gold or silver soldering, brazing and casting applications. Complete every soldering and melting job with confidence and ease! This system accepts all Little Torch accessory tips for melting, brazing and large soldering jobs and is a staple for every jeweler. |
| Heat-Resistant Safety Apron | Rio Grande | 750160 | The specially designed apron has an 800°F (427°C) temperature resistance. Its reflective finish repels hot metal splashes and helps insulate the wearer from heat. |
| Radnor Heat-Resistant Gloves | Rio Grande | 350050 | These flexible, heat-resistant gloves are ideal for enameling projects, allowing you to grip even small tongs securely. Blue, shoulder-split leather gloves are made of tough cowhide and lined with cotton and foam, and have reinforced thumb wings. |
| Platinum Soldering Glasses, #7 | Rio Grande | 113914 | Protect yourself and your employees when soldering platinum. Comfortable glasses feature adjustable earpieces and 52mm IR green polycarbonate #7 lenses. The #7 lens is approved by The Platinum Guild. |
| Economy Light-Duty Flask Tongs | Rio Grande | 704026 | Constructed of bent steel, these tongs are designed to handle flasks 3-1/2" or less in diameter. The small-angle notches grip smaller flask sizes and the larger, rounded contour area securely holds larger flasks. |
| Separating Screen Bucket | Rio Grande | 201360 | 15"-diameter, 11-1/2"-deep |
| Sand blaster – Econoline – 101701CB-A – Free-Standing Cabinets Workspace Width (Inch): 60 Workspace Depth (Inch): 48 | MSC industrial supply Co. | 223818 | Ree-Standing Cabinets; Workspace Width (Inch): 60; Workspace Depth (Inch): 48; Workspace Height (Inch): 40; Air Requirement: 12 CFM @ 80 psi; Overall Cabinet Width (Inch): 65; Maximum Cabinet Depth (Inch): 86 |
| Johnson's Baby Oil Shea & Cocoa Butter | Wal-Mart | 260074132 | This baby oil is used for removing the residue of the support material for the castable sacrificial pattern using Digital Ultrasonic Cleaner. |
| German 4" Saw Frame and Saw Blade Kit | Rio Grande | 110112 | Quality, German-made frames are our most popular saw frames, and this frame includes a sampler pack of Rio German saw blades! The adjustable saw frame allows you to achieve the blade tension you want. Throat depth is 102mm (4"). Saw blades have rounded backs that make cutting curves and corners easy and are made from hardened, tempered steel. |
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