Additive Manufacturing (AM) is a process of automating the building of 3-D structures like home items, vehicles, buildings, etc. One knows AM as 3-D Printing also. A process which makes physical objects using digital design.
Also, Additive Manufacturing needs 3D object Scanner or CAD software to get information on materials, number of layers and shape of each layer. Then, it adds material to create an object having exact required shape.
How AM Works
AM creates an object by creating layers. Each layer lies over other layer which differs in shape. Then, it sticks to the layer below it. The below layer has either melted or partially melted material. Also, materials used are thermoplastics, metal powder, composites, ceramics, chocolate, glass, etc.
A CAD software identifies the shape of Object. It creates a file with (extension .stl). This file contains 3-D drawing of the object. Then, using this file, the software can slice the object into very thin layers.
A nozzle is present on the machine which releases material to make the layer. Using information of layer from CAD software, it decides a path and follows it. Therefore, in this way, the nozzle makes perfect shape of the layer.
Alternative to nozzle, AM uses laser or electronic beam. It melts or partially melts in a bed of powdered material based on selection.
Then materials are allowed to cool with cure. As a result, materials of each layer sticks together to form a 3-D object.
Additive Manufacturing Process Types
1. Material Extrusion (ME)
ME process uses nozzles and beds. Nozzle moves horizontally and bed moves vertically. Here, nozzle takes a fixed path based on the shape of layer to move horizontally. Whereas bed keeps track of nozzle to complete its path. If completed then the bed moves down for a new layer.
This allow materials to be built layer by layer. Also, proper sticking of layers is ensured either by controlling the temperature perfectly or by using some chemicals. In the nozzle, the material is first heated and then is applied on the layer.
2. Direct Energy Deposition (DED)
DED is a complex process and is used for fixing or adding material to existing components. A DED Machine has nozzle fixed on an arm having multiple axis. It releases melted material on given surface where the material becomes solid.
DED’s process is almost similar to ME with slight difference. In DED, the nozzle can move in any direction and in ME, nozzle can move only horizontally. Materials given to DED is either in wire or in powdered form.
3. Material Jetting (MJ)
It uses the concept of 2-D ink jet printer for the process. So the material is dropped on the base surface where it becomes solid. Then, MJ builds the object layer by layer on base surface and nozzle moves in horizontal manner on the surface.
Different machines for MJ are available. They differ in ways of controlling the material released on build surface. UV light is used for curing and hardening the material. Since MJ releases materials as drops, so such materials are less. Waxes and Polymers are suitable as they are able to form drops.
4. Binder Jetting (BJ)
BJ allows printing objects with colors and the process is faster than others. It uses two materials i.e. binder and powdered based material. Binder is in liquid form which acts as a glue to make sure that each layer sticks with the one below it. Then, Powdered material is used for building a layer.
BJ has a print head which moves horizontally and vertically along the axis of machine. Then, it releases build material along with binder material in alternate layers. After completing each layer, object is lowered on the base surface.
5. Sheet Lamination (SL)
SL process include two methods of achieving it. These are Ultrasonic Additive Manufacturing (UAM) and Laminated Object Manufacturing (LOM).
UAM uses either metal ribbons or sheets. Ultrasonic welding binds these materials. Also, it needs additional CNC machining and removal of metal which are not bound in welding process.
LOM uses the same approach of layer by layer printing. It uses paper as material and adhesive other than welding. Also, it uses a method for printing which makes easy to remove materials after printing is completed.
Benefits of AM
1. Entry Cost and Equipment Cost is Cheap
In the beginning, companies had suffered high cost of equipment. Previously, AM machine was too costly for small manufacturers to keep it. But because of improvement in technology, the machine became affordable.
Also AM has capability to reduce the amount of capital needed to expand production. Without making big changes, manufacturers may able to increase the production speed.
2. Easy to Change or Improve the Product
AM not only can create a product, but can be used to innovate designs. It gives freedom to create new structures with least cost and time. AM solves the problem of old manufacturing method by allowing engineers to make various designs with speed in cost-effective manner.
Engineers using AM can easily make objects again and again without any human efforts.
3. Training is easy
AM needs operating and controlling the machine only. So training process becomes easy as compared to training on making the entire physical object which asks a lot of hard work.
The load of designing complex parts, deciding number of parts for an assembly, number of sub-assemblies in main assembly, etc is removed.
4. Material Wastes are less
In old way of manufacturing lot of materials are wasted. Because the processes involves i.e. cutting, carving, shaving the materials. Due to which the waste created cannot be reused.
But in AM, since it works on layers, so only required material are used. Rest other materials are saved. The nozzle uses material in a perfect manner and does not need to cut, carve or shave it.