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Additive Manufacturing:Fused Deposition Modelling, Selective Laser Sintering(SLS)

Additive Manufacturing(AM): As the name implies, additive manufacturing adds the material to create a 3D object. Additive Manufacturing is also called 3D Printing.

Contents:

1.Additive Manufacturing

1.1 Additive Manufacturing Materials

1.2 Additive Manufacturing Applications

1.3 Additive Manufacturing Advantages

2.Additive Manufacturing Technologies

2.1Fused Deposition Modeling(FDM)

2.1.1 Parts of Fused Deposition Modeling

2.1.2 Working of Fused Deposition Modeling

2.2 Selective Laser Sintering(SLS)

2.2.1 Parts of Selective Laser Sintering

2.2.2 Working of Selective Laser Sintering

 

 

 

Additive Manufacturing is a process in which the model of an object has to be created in any Modelling Software(CAD Software) and has to save in the format of.STL.

[.STL stands for Standard Triangular Language]

This format essentially “slices” the object into ultra-thin layers. Each successive layer bonds to the preceding layer of partially melted or melted material.

This file has to be sent to Additive Manufacturing machine or 3D Printing Machine to produce a 3D object in the form of fine layers.

The 3D Printing Machine understands the data in the(.STL) file created in CAD software by CAD Engineer and process accordingly in the form of smooth and Fine layers of plastic to create precise geometry shapes.

1.1 Additive Manufacturing Materials:

They are a variety of materials used in the Additive Manufacturing machine to create 3D objects and some of them are as follows.

1.Plastics(Thermoplastics)

One of the most popular materials used in Additive Manufacturing machine is Thermoplastics.

They are used because of the following reasons:

  • When it is heated, it turns soft and at this point, we can change the shape of the component.
  • Light Weight.
  • It is recyclable.

Ex: Acrylonitrile Butadiene Styrene (ABS), Polycarbonate (PC) and Polylactic Acid (PLA) offer distinct advantages in various applications.

2.Ceramics:

A variety of ceramics are also been used in additive manufacturing such as Zirconia,

Tricalcium phosphate, alumina etc.

3.Metals:

Metals and Metal alloys are used in additive manufacturing machine from precious metals like gold, silver etc. to strategic metals like stainless etc.

1.2 Additive Manufacturing Applications:

1.Aerospace:

Additive Manufacturing excels in producing the components for aerospace applications which are light in weight and stronger enough to withstand the desired load.

Ex: Jet engine parts.

2.Automotive Industry:

Aluminum alloys are used to produce exhaust pipes and parts of the pump, and polymers are used to produce bumpers of an automobile.

3.Health Care:

  • At, New York University School of Medicine, a study of 300 patients will evaluate the efficacy of patient-specific, multi-colored kidney cancer models using additive manufacturing.
  • 3D printed surgical implants for patients suffering from bone cancer disease.

1.3 Additive Manufacturing Advantages:

  • AM creates the components which are lighter, stronger and which otherwise by conventional methods(machining etc) takes huge time, money etc.
  • In AM, which offers digital-to-digital process eliminates traditional machining and offers a more dynamic, design-driven process.
  • The Lead time is frequently reduced in AM compared to Traditional.
  • The parts which are assembled in traditional methods can be eliminated by fabricating into single components in Additive Manufacturing.

2.Additive Manufacturing Technologies:

There are various Additive Manufacturing Technologies and a few of them are as follows.

  1. Fused Deposition Modelling(FDM)
  2. Selective Laser Sintering(SLS)
  3. Vat Photopolymerization
  4. Material Jetting
  5. Binder Jetting
  6. Direct Energy Deposition

Two of the popular additive manufacturing Technologies are presented below

2.1 Fused Deposition Modelling(FDM):

It is one of the Rapid Prototyping techniques which fuses or melts the material(similar to extrusion Process) and deposit in the form of layer by layer in order to construct a component whose data had been taken from the cad(.stl) file.

Additive Manufacturing-Fused deposition modelling
Additive Manufacturing-Fused deposition modeling

2.1.1 Parts of Fused Deposition Modelling:

  1. Base(For Support)
  2. Filament (Plastic Material)
  3. Feed Rollers (Provide the proper amount of material)
  4. Supply Rollers (Supply plastic material at the beginning)
  5. Heating Elements (Heats the Plastic to a semi-liquid state)
  6. Nozzle or Extrusion Chamber

2.1.2 Working of Fused Deposition Modelling(FDM):

In this process, the raw material is a plastic component, which is also called as a filament in FDM technique is drawn by means of rollers and is to be passed into the heating chamber by means of Feed rollers.

The plastic material is to be heated up to the formation of semi-liquid and is to be passed into the extrusion chamber.

In the Extrusion chamber, it has to be passed through a nozzle(similar to the extrusion process) and the product is obtained in the form of layers.

This is the detailed explanation about the working of the fused deposition modeling technique in additive manufacturing.

2.2 Selective Laser Sintering(SLS):

It is also one of the Rapid Prototyping Technique which uses laser machine for sintering the raw material to get the desired shape in the form of layer by layer.

Sintering means heating the raw material(Powder) so that it is melted and converted into a thick layer called as sintering.

It is a process that creates a physical object from a digital design. The engineering design of a model can be prepared in CAD software.

The design file(.stl) is then sliced Into small layers of equal thickness and Uploaded to an additive manufacturing machine.

Above figure shows the sintering of the material layer by layer to form a final component.

Selective laser sintering-Additive manufacturing
Selective laser sintering-Additive manufacturing

2.2.1 Parts of Selective Laser Sintering:

  1. Laser
  2. Scanner
  3. Powder
  4. Chambers with Piston Arrangement
  5. Roller

2.2.2 Working of Selective Laser Sintering:

The manufacturing process begins once the thin layer of metal powder is spread across the platform.

On the Platform, two chambers are present with Piston arrangement. One piston is moving up and the other piston is moving down as shown in the figure.

The First Chamber Piston pushes up the powder so that it is above the platform. Now roller will push and spread the powder to another chamber.

The Second chamber whose piston is pushed down so that the powder material has to be filled in the form of layer by layer.

Now, a heat source such as laser or electron beam then notes the first layer of the 3D design and scanner can scan the work region and post the laser so that the powder melts and deposits on the work platform in the form of layers.

The platform is loaded again and the layer of metal powder is spread across the platform.

The layering and melting process is then repeated till the process is complete.

The metallic powder is removed and the physical object is revealed or taken out from the powder and was cleaned so that impurities cannot be deposited.

Watch the video below to understand the concept of SLS Process:

The parts produced by the Selective Laser Sintering are lighter, stronger and more adorable than traditional or Conventional parts.

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