Experimental Determination of Uniform Heating in the Selective Laser Sintering Part Bed

Becca Statum

Abstract


Selective Laser Sintering (SLS) is an Additive Manufacturing (AM) process in which powdered material is spread out on a part bed and sintered with a laser layer upon layer in succession. The design for this part is usually prescribed by a CAD file uploaded to the SLS computer system. Part bed temperature is typically raised to just below the melting temperature of the material being processed. It is critical that the part bed temperature remain uniform in the selective laser sintering machine, so that warping and shrinking of the part leading to defects does not occur. A user-friendly testing method was developed to ascertain whether or not the part bed is at uniform temperature so heating adjustments can be made accordingly. The optimum heater setting for various zones was established using a structure of a thermocouple-embedded, 0.25-in think, 12-in by 12-in polytetrafluoroethylene (PTFE) sheet. Testing was conducted on a multi-zone SLS machine for various heater settings to establish the optimum parameters needed to maintain a uniform temperature throughout the structure. It was determined that recommended settings were keeping a relative uniform temperature while uniform heater settings were not. Optimum settings were decided upon and tested to reveal a more uniform temperature distribution than before. Testing was then conducted on a regular SLS machine with only two heater zones; it was concluded that this machine was not as consistent nor as capable in keeping a uniform temperature as the multi-zone SLS machine.


Keywords


Laser Sintering, part bed, uniform temperature, multi-zone heater

Full Text: PDF

Refbacks

  • There are currently no refbacks.