Rapid Prototyping Of Die Casting .. Presentation

RAPID PROTOTYPING OF DIE CASTING, INVESTMENT CASTING COMPONENTS IN INDUSTRY Guided By Prof. D.V. Shirbhate Submitted By Ashish B. Agrawal Sudhir D. Godle Ku. Vaishali R. Joshi Mangesh H. Kambekar

Scope of Project •

The project work is assigned by Professor D.S. Ingole, Assistant Professor, Department of Production Engineering, College of Engineering and Technology Badnera.

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The work consist of developing the rapid prototype model of Maruti 800 and investment, die casting components of Jadhav Steel and Alloys

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The Company have hard copy drawing which needs to e converted into solid models for better understanding and rapid prototyping

Method by which project work is carried out Step 1 Drawing reading Step 2 Learning of CATIA software to develop the model. Step 3 Conversion of CAT format into STL format for rapid prototyping Step 4 Developing rapid prototype model by FMD process

Introduction to Rapid Prototyping The term Rapid Prototyping (RP) refers to a class of technologies that can automatically construct physical models from Computer-Aided Design (CAD) data. These "three dimensional printers" allow designers to quickly create tangible prototypes of their designs, rather than just twodimensional pictures. Such models have numerous uses. They make excellent visual aids for communicating ideas with co-workers or customers. In addition, prototypes can be used for design testing. The technique are often collectively refer to as solid free form fabrication CAM or layered manufacturing

Rapid Prototyping Techniques •

Stereolithography

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Laminated object manufacturing

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Selective laser sintering

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Fused deposition modeling

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Solid ground curing

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Ink-Jet printing

Stereolithography Patented in 1986, stereolithography started the rapid prototyping revolution. The Stereolithography process is the most widely used of all Rapid Prototyping processes in the year 2004. The technique builds three-dimensional models from liquid photosensitive polymers that solidify when exposed to ultraviolet light. As shown in the figure below, the model is built upon a platform situated just below the surface in a vat of liquid epoxy or acrylate resin. A low-power highly focused UV laser traces out the first layer, solidifying the model’s cross section while leaving excess areas liquid.

Schematic diagram of stereolithography HeCd laser Lenses

Mirror Elevator

Liquid polymer

HeNe laser Platform

Laminated Object Manufacturing In this technique, developed by Helisys of Torrance, CA, layers of adhesive-coated sheet material are bonded together to form a prototype. The original material consists of paper laminated with heat-activated glue and rolled up on spools. As shown in the figure below, a feeder/collector mechanism advances the sheet over the build platform, where a base has been constructed from paper and double-sided foam tape. Next, a heated roller applies pressure to bond the paper to the base. A focused laser cuts the outline of the first layer into the paper and then crosshatches the excess area

Laser

Mirror Heated roller

Feeder

Optical head

Platform Collector

Schematic diagram of laminated object manufacturing.

Selective Laser Sintering Developed by Carl Deckard for his master’s thesis at the University of Texas, selective laser sintering was patented in 1989. The technique, shown in Figure, uses a laser beam to selectively fuse powdered materials, such as nylon, elastomer, and metal, into a solid object. Parts are built upon a platform which sits just below the surface in a bin of the heat-fusable powder. A laser traces the pattern of the first layer, sintering it together. The platform is lowered by the height of the next layer and powder is reapplied.

Schematic Diagram of Selective Laser Sintering

Solid Ground Curing In this process photosensitive resin is sprayed on the build platform. Next, the machine develops a photomask (like a stencil) of the layer to be built. This photomask is printed on a glass plate above the build platform using an electrostatic process similar to that found in photocopiers. The mask is then exposed to UV light, which only passes through the transparent portions of the mask to selectively harden the shape of the current layer. After the layer is cured, the machine vacuums up the excess liquid resin and sprays wax in its place to support the model during the build. The top surface is milled flat, and then the process repeats to build the next layer. When the part is complete, it must be de-waxed by immersing it in a solvent bath.

UV Light Source Spray Resin Develop photomask Expose mask Vacuum uncured resin

Spray wax Mill flat

Schematic diagram of solid ground curing

3-D Ink-Jet Printing Ink-Jet Printing refers to an entire class of machines that employ ink-jet technology. Parts are built upon a platform situated in a bin full of powder material. An ink-jet printing head selectively deposits or "prints" a binder fluid to fuse the powder together in the desired areas. Unbound powder remains to support the part. Typical layer thicknesses are on the order of 0.1 mm. This process is very fast, and produces parts with a slightly grainy surface. Machines with 4 color printing capability are available. 3D Systems' version of the ink-jet based system is called the Thermo-Jet or Multi-Jet Printer. It uses a linear array of print heads to rapidly produce thermoplastic models.

Fused Deposition Modeling In this technique, filaments of heated thermoplastic are extruded from a tip that moves in the x-y plane. Like a baker decorating a cake, the controlled extrusion head deposits very thin beads of material onto the build platform to form the first layer. The platform is maintained at a lower temperature, so that the thermoplastic quickly hardens. After the platform lowers, the extrusion head deposits a second layer upon the first. Supports are built along the way, fastened to the part either with a second, weaker material or with a perforated junction. There are variety of FDM machines ranging from fast concept modelers to slower, high-precision machines. Materials include ABS (standard and medical grade), elastomer (96 durometer), polycarbonate, polyphenolsulfone, and investment casting wax.

Schematic diagram of fused deposition modeling.

DM features Competitive with other RP technologies Strong and durable model APS plastic (with color choices) and Elastomer material choices Water proof, paintable

FDM Applications •

Si3N4 components with good mechanical properties and microstructure were produced with a filament containing 55 vol % of the ceramic. After FDM, green parts were densified by hot pressing and gave four point bend strengths similar to that of hot isostatic pressed parts.

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A fine scaled piezoelectric composite structure can be made consisting of PZT AND POLYMER. The piezoelectric properties of the composite are similar or superior to conventionally processed PZT composites.

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Composites with controlled composition distribution and a variety of microstructures can be made by combining filaments of different compositions.

Investment casting Investment casting is a versatile process, used to manufacture parts ranging from turbocharger wheels to golf club heads, from electronic boxes to hip replacement implants. The industry, through heavily dependent on aerospace and defence outlets, has expended to meet a widening range of applications. Modern investment casting ha its adoption of jet propulsion for military and then for civilian aircraft. Investment casting expanded greatly worldwide during the 1980s in particular to meet growing demands for aircraft engine and airframe industry, with investment castings now accounting for 15 per cent by value of all cast metal production in the inducers.

Materials are used in investment casting Investment casting is used for a wide range of applications, small parts from the bulk of production, but the very large components, can be be made commercially. Nickel and cobalt base super alloys account for 50 per cent of total output by value, steels of all account for 35 per cent , aluminium accounts for about 10 per cent and copper ant titanium alloys make up a large part of the remaining 5 per cent.

The Basic Process Although several rapid prototyping techniques exist,

all

employ

the

same

basic

five-step

process. The steps are: •

Create a CAD model of the design

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Convert the CAD model to STL format

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Slice the STL file into thin cross-sectional layers

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Construct the model one layer atop another

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Clean and finish the model

SOLID MODELS DRAWN IN CATIA FOR RAPID PROTOTYPING

Yoke Gear Shift

Bracket

Bracket Engine Mounting

Engine Hook

Hose Outlet

Oil Transmission Pan

JSAM1

Pump Assay Water

Applications of Rapid Prototyping Rapid prototyping is widely used in the automotive, aerospace, medical, and consumer products industries. Although the possible applications are virtually limitless, nearly all fall into one of the following categories: prototyping, rapid tooling, or rapid manufacturing. 5. Prototyping 6. Rapid tooling • Indirect tooling • Direct tooling • Rapid manufacturing

Future Development •

Rapid prototyping is starting to change the way companies design and build products.

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One such improvement is increased speed. "Rapid" prototyping machines are still slow by some standards. By using faster computers, more complex control systems, and improved materials, RP manufacturers are dramatically reducing build time. Continued reductions in build time will make rapid manufacturing economical for a wider variety of products.

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Another future development is improved accuracy and surface finish. Today’s commercially available machines are accurate to ~0.08 millimeters in the x-y plane, but less in the z (vertical) direction.