3D打印技术资料.docx

1、3D打印技术资料3D printingFor methods of applying a 2D image on a 3D surface, see pad printing. For methods of printing 2D parallax stereograms that seem 3D to the eye, see lenticular printing and holography.An ORDbot Quantum 3D printer.Timelapse video of a hyperboloid object (designed by George W. Hart) m

2、ade of PLA using a RepRap Prusa Mendel 3D printer for molten polymer deposition.3D printing or Additive manufacturing1 is a process of making a three-dimensional solid object of virtually any shape from a digital model. 3D printing is achieved using an additive process, where successive layers of ma

3、terial are laid down in different shapes.2 3D printing is also considered distinct from traditional machining techniques, which mostly rely on the removal of material by methods such as cutting or drilling (subtractive processes).A 3D printer is a limited type of industrial robot that is capable of

4、carrying out an additive process under computer control.While 3D printing technology has been around since the 1980s, it was not until the early 2010s that the printers became widely available commercially.3 The first working 3D printer was created in 1984 by Chuck Hull of 3D Systems Corp.4 Since th

5、e start of the 21st century there has been a large growth in the sales of these machines, and their price has dropped substantially.5 According to Wohlers Associates, a consultancy, the market for 3D printers and services was worth $2.2billion worldwide in 2012, up 29% from 2011.6The 3D printing tec

6、hnology is used for both prototyping and distributed manufacturing with applications in architecture, construction (AEC), industrial design, automotive, aerospace, military, engineering, civil engineering, dental and medical industries, biotech (human tissue replacement), fashion, footwear, jewelry,

7、 eyewear, education, geographic information systems, food, and many other fields. One study has found7 that open source 3D printing could become a mass market item because domestic 3D printers can offset their capital costs by enabling consumers to avoid costs associated with purchasing common house

8、hold objects.8TerminologyThe term additive manufacturing refers to technologies that create objects through sequential layering. Objects that are manufactured additively can be used anywhere throughout the product life cycle, from pre-production (i.e. rapid prototyping) to full-scale production (i.e

9、. rapid manufacturing), in addition to tooling applications and post-production customization.9In manufacturing, and machining in particular, subtractive methods refers to more traditional methods. The term subtractive manufacturing is a retronym developed in recent years to distinguish it from newe

10、r additive manufacturing techniques. Although fabrication has included methods that are essentially additive for centuries (such as joining plates, sheets, forgings, and rolled work via riveting, screwing, forge welding, or newer kinds of welding), it did not include the information technology compo

11、nent of model-based definition. Machining (generating exact shapes with high precision) has typically been subtractive, from filing and turning to milling, drilling and grinding.9The term stereolithography was defined by Charles W. Hull as a system for generating three-dimensional objects by creatin

12、g a cross-sectional pattern of the object to be formedin a 1984 patent.1011General principles3D model slicing.PrintingTo perform a print, the machine reads the design from an STL file and lays down successive layers of liquid, powder, paper or sheet material to build the model from a series of cross

13、 sections. These layers, which correspond to the virtual cross sections from the CAD model, are joined or automatically fused to create the final shape. The primary advantage of this technique is its ability to create almost any shape or geometric feature.Printer resolution describes layer thickness

14、 and X-Y resolution in dpi (dots per inch),citation needed or micrometers. Typical layer thickness is around 100 ?m (250DPI), although some machines such as the Objet Connex series and 3D Systems ProJet series can print layers as thin as 16 ?m (1,600DPI).12 X-Y resolution is comparable to that of la

15、ser printers. The particles (3D dots) are around 50 to 100 ?m (510 to 250DPI) in diameter.Construction of a model with contemporary methods can take anywhere from several hours to several days, depending on the method used and the size and complexity of the model. Additive systems can typically redu

16、ce this time to a few hours, although it varies widely depending on the type of machine used and the size and number of models being produced simultaneously.Traditional techniques like injection molding can be less expensive for manufacturing polymer products in high quantities, but additive manufac

17、turing can be faster, more flexible and less expensive when producing relatively small quantities of parts. 3D printers give designers and concept development teams the ability to produce parts and concept models using a desktop size printer.FinishingThough the printer-produced resolution is suffici

18、ent for many applications, printing a slightly oversized version of the desired object in standard resolution and then removing material with a higher-resolution subtractive process can achieve greater precision.citation neededSome additive manufacturing techniques are capable of using multiple mate

19、rials in the course of constructing parts. Some are able to print in multiple colors and color combinations simultaneously. Some also utilize supports when building. Supports are removable or dissolvable upon completion of the print, and are used to support overhanging features during construction.A

20、dditive processesRapid prototyping worldwide 200113The Audi RSQ was made with rapid prototyping industrial KUKA robots.Several different 3D printing processes have been invented since the late 1970s. The printers were originally large, expensive, and highly limited in what they could produce.14A lar

21、ge number of additive processes are now available. They differ in the way layers are deposited to create parts and in the materials that can be used. Some methods melt or soften material to produce the layers, e.g. selective laser melting (SLM) or direct metal laser sintering (DMLS), selective laser

22、 sintering (SLS), fused deposition modeling (FDM), while others cure liquid materials using different sophisticated technologies, e.g. stereolithography (SLA). With laminated object manufacturing (LOM), thin layers are cut to shape and joined together (e.g. paper, polymer, metal). Each method has it

23、s own advantages and drawbacks, and some companies consequently offer a choice between powder and polymer for the material from which the object is built.15 Some companies use standard, off-the-shelf business paper as the build material to produce a durable prototype. The main considerations in choo

24、sing a machine are generally speed, cost of the 3D printer, cost of the printed prototype, and cost and choice of materials and color capabilities.16Printers that work directly with metals are expensive. In some cases, however, less expensive printers can be used to make a mould, which is then used

25、to make metal parts.17TypeTechnologiesMaterialsExtrusionFused deposition modeling (FDM)Thermoplastics (e.g. PLA, ABS), HDPE, eutectic metals, edible materials, Rubber (Sugru), Modelling clay, Plasticine, RTV silicone, Porcelain, Metal clay (including Precious Metal Clay)WireElectron Beam Freeform Fa

26、brication (EBF3)Almost any metal alloyGranularDirect metal laser sintering (DMLS)Almost any metal alloyElectron-beam melting (EBM)Titanium alloysSelective laser melting (SLM)Titanium alloys, Cobalt Chrome alloys, Stainless Steel, AluminiumSelective heat sintering (SHS) 18Thermoplastic powderSelectiv

27、e laser sintering (SLS)Thermoplastics, metal powders, ceramic powdersPowder bed and inkjet head 3D printingPlaster-based 3D printing (PP)PlasterLaminatedLaminated object manufacturing (LOM)Paper, metal foil, plastic filmLight polymerisedStereolithography (SLA)photopolymerDigital Light Processing (DL

28、P)photopolymerExtrusion depositionFused deposition modeling: 1 nozzle ejecting molten plastic, 2 deposited material (modeled part), 3 controlled movable table.Main article: Fused deposition modelingFused deposition modeling (FDM) was developed by S. Scott Crump in the late 1980s and was commercializ

29、ed in 1990 by Stratasys.19 With the expiration of the patent on this technology there is now a large open-source development community, as well as commercial and DIY variants, which utilize this type of 3D printer. This has led to a two orders of magnitude price drop since this technologys creation.

30、In fused deposition modeling the model or part is produced by extruding small beads of material which harden immediately to form layers. A thermoplastic filament or metal wire that is wound on a coil is unreeled to supply material to an extrusion nozzle head. The nozzle head heats the material and t

31、urns the flow on and off. Typically stepper motors or servo motors are employed to move the extrusion head and adjust the flow and the head can be moved in both horizontal and vertical directions. Control of this mechanism is typically done by a computer-aided manufacturing (CAM) software package ru

32、nning on a microcontroller.Various polymers are used, including acrylonitrile butadiene styrene (ABS), polycarbonate (PC), polylactic acid (PLA), high density polyethylene (HDPE), PC/ABS, and polyphenylsulfone (PPSU). In general the polymer is in the form of a filament, fabricated from virgin resins. Multiple projects in the open-source community exist that are aimed at processing post-consumer plastic waste into filament. These involve machines