IKBAL AHMED13PH40016

DEPARTMENT OF PHYSICSIIT KHARAGPUR

3DPRINTING

WHAT IS 3D PRINTING

1.) 3D printing refers to any of the various methods used for printing a three dimensional object.

2.) Primarily additive processes are used where successive layers of material are laid down with the help of computer.

3.) Objects of almost any kind or shape may be printed by this method.

4.) It is a kind of INDUSTRIAL ROBOT.

HOW IT WORKS

MODELING STL FILE SLICER SOFTWARE Cura,slic3r

G CODE FILE

PRINTINGFINISHING

Technology , for printing 3d objects from digital data ,first developed by CHARLES HULL in 1984.

He named the technique as stereo lithography and obtained a patient for the same in 1986.

By the end of 1980 SLS, FDM methods were introduced.

In 1993 MIT patented another technology named 3 dimensional printing technique .

In 2005,z corp. made a product named spectrum z510 which was the first high definition colour 3d printer.

HISTORY

• Granular type formation, have a wide range of materials.

• Used materials are thermoplastics, metal powders, ceramic powders.

1. SELECTIVE LASER

SINTERING (SLA)

• Extrusion type, printed materials have high strength and durability.

• Mainly thermoplastics, rubber metal-clay, porcelain are used.

2. FUSED DEPOSITION

MODELLING (FDM)

• Light polymerised type, highly complex objects can be made.

• Photopolymers are used

3.STEREOLITHOGRAPHY

(SLA)INKJET POWDER PRINTING, ELECTRON BEAM MELTING (EBM), SELECTIVE LASER MELTING (SLM), PLASTER

BASED PRINTING, LAMINATED OBJECT

MANUFACTURING (LOM) etc.

3D PRINT TECHNIQUES

SELECTIVE LASER SINTERING

1) POWERFUL LASER AND POWDER MATERIAL.

2) A HIGH POWER LASER FUSES SMALL PARTICLES OF PLASTIC, METAL OR CERAMIC POWDERS.

3) CAN BE USED FOR WIDE MATERIAL RANGE.

4) TYPICAL THICKNESS IS AROUND 100 μm

SINTERING

Def- A process of forming solid mass by heating without melting it to the point of liquefaction.

DENSIFICATION PROCESS-

1) Bulk coupling2) Powder coupling

≛ it is high power density, short interaction time process.

DENSIFICATION RATE-

1) Process parameters2) Material properties(assuming constant)

Parameters affecting energy delivered to the surface are- 1) laser power (P) 2) laser beam diameter (d) 3) scan rate (v) 4) scan line spacing (h)

Energy density , Q=πɳP H4dv

Where, ɳ is coupling efficiency

1.) Sintering temperature, T(s)= T(0) +1/C [ πɳ/4ρ (P/hvw) - ∆H ] it is a empirical relation.where, w is layer density , C is specific heat, T(s) is sintering temp , T(0) is initial temp, ρ is density and ∆H is latent heat.

2.) The rate of change in void fraction of powder bed is , d€/dt = -k€, €(i) ≤ € ≤ €(s) where k is sintering rate and € is void fraction.

3.) empirically , k ⋉ P/wh

4.) Full densification can not be obtained

STEREO-LITHOGRAPHY

stereo lithography

layer thickness~ .05-.15mm

It is additive manufacturing process with ultraviolet curable ‘resin’ and uv- laser

High speed manufacturing .Complex objects are made.But photo curable resin and the machine is too expensive

How SLA works

P-I R* (free radical formation)

M + R* R-M* (initiation)

RM* +RM* →RM-MR (termination)

→

→

nRM* → R-M-M-M-M* (propagation)

WORKING CURVE EQUATION FOR RESIN

From BEER-LAMBERT law, it can be shown that,

C=Dln[E(max)/E(crt)) Where C is cure depth, D is depth of penetration by laser until irradiance becomes 1/e, E(max) is peak exposure of laser and E(crt) is critical exposure.

A SEMILOG PLOT OF C VS E(max)

WHY 3D PRINTING1.) Increase innovation

2.) Reduce development costs

3.) Improve communications-(like, recently a 3D printer has been sent to space (by NASA’s MARSHALL SPACE FLIGHT CENTER in Huntsville, Ala) to help astronauts building replacement parts or any other important tools )

4.) Win business.

APPLICATIONSEducation and research

1.)Beam trapper for absorbing radar radiation to camouflage military aircrafts, ships, buildings .

2.) complex models, cross sections, architectural designs can be made for practical purposes.

A beam trapper made by swiss researchers from ETH Zurich Institute

IN BIOSCIENCE 1.)Different organ models like nose, kidney, skin can be made by bio materials for replacements2.) Nanoscale bio printing can be used for replacement parts according to genetics.

IN INDUSTRY

Most of the applications are industrious of 3D printing. Starting from small machine tools to 3D printed home are made cheaply.In automobiles, medicines, firearms, art it has huge applications.

3d printed home in china3D printed car

4. "How Stereo lithography Works". THRE3D.com. Retrieved 4 February 2014

2. Jacobs PF (1992) Rapid prototyping & manufacturing, fundamentals of stereo lithography. Society of Manufacturing Engineers, New York, NY

3. http://www.space.com/23532-3d-printer-space-station-video.html

REFERENCES and SOURCES

1.)www.elsevier.com/locate/msea; A. Simchi / Materials Science and Engineering A 428 (2006) 148–158

THANK YOU