XLENCE AM 3D INERTION PRINTER
Embedded Files
BACKGROUND
Metal 3D Printers use high-powered lasers to selectively fuse metal powder on the print bed while simultaneously preventing oxidation in the metal prints by introducing an inert gas such as argon or nitrogen. Although current metal printers in the industry use vacuum chambers to minimize the need for multiple argon purge cycles, the design is restricted by the inextensible limitations of its print area. As the printable area increases, the bulkier the vacuum chamber needs to be to withstand atmospheric pressure. Ensuring a leak-proof system also requires expensive components, many engineering hours, and a significant amount of testing to prevent leakage. These chambers also depend on multiple argon purge cycles to displace oxygen at the print area, making it an inefficient use of argon. In general, current metal 3D printers are bulky, expensive, and difficult to use due to the limitations created by vacuum chambers. Innovation in this area is necessary if metal 3D printing is to be considered a viable option in comparison to traditional manufacturing methods.
OBJECTIVE
Make More & Vacuum-Less !
To put our objective into context, we must first reflect on how the current manufacturing industry is split. There is a general understanding by some that a vacuum chamber is necessary, as they find it necessary in limiting the exposure of the metal powders to atmospheric gasses and almost completely necessary to ensure purity in a metal print.
Therefore, our objective as a team was to prove that a vacuum-less design in a Metal 3D printer is viable. That is, that removing the vacuum chamber does not mean sacrificing quality in metal prints. In order to demonstrate how viable this innovative design is, the project must prove that oxygen concentration levels at the print area below 1% are possible while still minimizing the argon gas usage in the system. The design must also be able to maintain these oxygen levels despite motion in XYZ directions.
THE SOLUTION
The Gantry — one fluid motion
The Gantry — one fluid motion
In order to complete our objective, the first step was creating a Gantry System capable of:
creating parts in a 1ft. x 1ft. x 1ft. print area
supporting a fluidics loop system
capable of simple interface and movement
being easily extensible
The Fluidics Loop — impurities ar-gone
The Fluidics Loop — impurities ar-gone
Second came the fluidics loop, necessary for proving that vacating oxygen in a print area is in fact possible. This was done by:
implementing a nozzle for the dispersion of argon gas
driving the fluidics system with a blower
using an O2 sensor to ensure that the 1% oxygen concentration goal is being met
RESULTS
RESULTS
OPTIMAL CONFIGURATIONS
The surface plot on the upper left is a three-dimensional graph that shows the various configurations of PWM inputs and argon tank flow rates (CFH) that allow the system to maintain a steady-state oxygen concentration less than 1% which is shown in green. From the graph on the right, it is evident that lower PWM inputs and higher flow rates from the argon tank allow the system to achieve such a goal.
The importance of the optimization of the system is ultimately related to making the system more cost effective. Minimizing the use of argon is very important as metal 3D prints can typically range from thirty minutes to several days which highlights the importance of optimizing the system and using less argon to achieve the goal of 1 % oxygen concentration on the print bed.
Page updated
Report abuse