What is 3D Metal Printing?
3D Printing is a method of merging material to form an object, usually by layer to layer and providing a required shape and size while forming a real-time and a real structure. 3D Printing is also known as ‘Additive Manufacturing’. It is a tool-less method of manufacturing parts directly from digital models and merging the metals at a defined shape.
3D printing has been started since the 1980s, and the first material was a small cup and designed and printed by 'Chuck Hall'. The multiple thinly sliced layers are arranged in a cross-section of the actual image. 3D Printing manufacturing requires less material than the traditional manufacturing process. The method of working on 3D printing requires visualization of real life 3-dimensional image, which is prepared by using the computer software. The final image has been sent as a command form to the printer which creates the 3D structure.
How does 3D Metal Printer Works?
Normal Printers works by only melting the plastic, and then depositing it while giving a defined shape. Whereas the melting point of metals is too high, so 3D Metal Printing follows a different approach.
According to the efficiencies of the various methods, only 2 methods are used for 3D Metal Printing.
1. Binder Jetting, and
2. Selective Laser Melting.
Working Process of Binder Jetting
Binder Jetting Print process involves the following steps:
1. To prevent the oxidation of the metal, the build chamber is filled with an Inert Gas like Argon.
2. A metal powder layer is spread according to the flow of properties having the thickness of about 20 to 50 microns.
3. As per the requirement of models outline, a polymer compound has been spread automatically to create a layer.
4. This step is repeated until the model has been completed.
5. The excess powder has been collected for future use. Before using it again the powder has been filtered and refreshed by adding unused powder.
6. The accuracy level of the printed model is within ±0.1 mm.
After the model has been completed, the object has poor mechanical strength and high porosity. So, to minimize this, it can be treated in either of the two ways:
a) Sintering: After the printing of the model, it has been placed in a high-temperature furnace. Where the mechanical strength of the model is increased and porosity is decreased.
b) Infiltration: In this process also the model has been put into the furnace, where 40% of its voids has been removed. Then it is infiltrated with Bronze to fill the remaining voids. Through this process, 90% of voids are removed from the model.
Working of Selective Laser Melting
Selective Laser Melting is slightly different from the Binder Jetting Process. It follows the following step.
1. The build chamber is filled with Inert Gas, a layer of metal powder is spread over the floor.
2. To create the solid layer of the object, the powder has been fussed with the laser.
3. As the layer is made the platform moves downwards by 50 to 200 microns. Then using the re-coater another layer of metal powder is spread.
4. Then the laser scans the whole area and fuses the new layer of metal. To finish the component repeat the step again and again.
5. Here also the excess powder has been extracted from the machine and filtered and mixed with fresh powder to reuse again.
Selective Laser Melting process doesn’t require Sintering or Infiltration process to remove the voids. So, the final product of Selective Laser Melting has higher mechanical strength. Which makes this method to be preferred more as compared to the Binder Jetting Process.
While, the metal powder is reused in both the techniques, and it minimizes the amount of waste to less than 5%.
Some Real-World Examples of 3D Printing
1. Prosthetic Limbs and Other Body Part
In the veterinary field, to save the life of an injured dog. Doctors used the 3D Printed mask to avoid the severe face injury. The experiment has been conducted over a mouse as well in a Medicine University, Chicago. The mouse ovaries have been replaced with 3D Printed ovaries and it gave birth to a healthy baby.
2. Constructing Homes and Buildings
In Moscow, with the help of #D Printing Technology, a 400 square foot house has been built in less than 24 hours. The speed of building the house will be very helpful during a natural calamity, where the need of house would be at its peak.
3. Edible 3D Printing
This technique is very much in use in the Baking Industry, where decorating a cake is the biggest task. 3D Printer makes decorating design while chocolate or any other eatable, and with sheer precision and accuracy each layer of design has been made.
In Automobile Industry the 3D Printers are used very efficiently to save the time and minimize the manufacturing cost. It is maximally used in the car industry, where the many designer parts are made by using the 3D Printers.