Large area sintering test platform and associated method of use
A large area sintering platform, system, and methodology. The system includes a convection oven with a projection window disposed within a top surface of the oven. A platform is disposed within the oven below the window at a spaced distance away from the window. A powder is positioned on top of the platform, with a thermocouple positioned within the powder on the platform. A high intensity projector moves in sync with the platform, and uses low intensities and long exposure times to project an image through the window onto the powder and sinter the powder to fabricate the desired model layer by layer.
1. A system for sintering a powder, comprising:
a sintering chamber comprising a window;
a platform positioned within the sintering chamber and at a spaced apart distance from the window, wherein the platform holds a powder layer thereupon;
a powder preheating mechanism to preheat the powder layer on the platform; and
a high intensity projector disposed in overlying relation to the window and positioned to project an image through the window, wherein the high intensity projector projects an image at a wavelength through the window and onto the powder layer at a predetermined optical intensity, whereby the system heats and sinters the powder layer based upon the image projected from the high intensity projector, resulting in a 2D cross-sectional layer of sintered powder.
2. The system of claim 1 , wherein the powder layer comprises one or more combinations of a polymer, a metal, and a ceramic.
3. The system of claim 1 , wherein the window is transparent to a majority of the wavelength of light provided by the projector and opaque or reflective to a majority of light in a temperature sensing wavelength band.
4. The system of claim 1 , wherein the window further comprises a lens.
5. The system of claim 1 , further comprising a powder reservoir for depositing additional powder layers onto the platform for generation of subsequent 2D cross sectional layers of sintered powder.
6. The system of claim 5 , wherein the system further comprises a rotating drum combined with the powder reservoir for depositing additional powder layers onto the platform for generation of subsequent 2D cross sectional layers of sintered powder.
7. The system of claim 6 , wherein the rotating drum comprises one or more grooves.
8. The system of claim 5 , wherein the reservoir is combined with a synchronized movement of the platform to control deposition of additional powder layers onto the platform.
9. The system of claim 1 , wherein the platform is movable within the chamber relative to the window, thus permitting the projector to sinter large areas on the platform.
10. The system of claim 1 , wherein the projector includes an optical power provided by one of, an ultra-high-pressure mercury vapor lamp, a metal halide lamp, a high intensity discharge lamp, a high-pressure sodium lamp, a low-pressure sodium lamp, a light emitting diode and a laser, to transmit light in the visible or ultraviolet spectrum.
11. The system of claim 1 , further comprising a temperature measurement device to measure the temperature of the powder layer on the platform.
12. The system of claim 1 , wherein the system further comprises a closed loop temperature control of the projector to sinter the powder layer.
13. The system of claim 12 , wherein the closed loop temperature control of the projector further comprises:
a thermal camera to monitor temperatures of the 2D cross sectional layer of sintered powder to generate monitored temperatures, wherein
the monitored temperatures are passed through a control algorithm to compare the monitored temperatures to desired temperatures; and
a signal is transmitted to the projector to alter a temperature of the projector based on a difference between the monitored temperatures and the desired temperatures.
14. The system of claim 12 , wherein the window transmits the wavelength at which the high intensity projector projects the image while acting as a mirror to reflect the wavelength at which the monitored temperature is measured.
15. The system of claim 12 , wherein the system further comprises one or more mirrors, and wherein the one or more mirrors are optionally metal or metal coated.
16. The system of claim 15 , wherein a light at the wavelength for the monitored temperature is transmitted to a separate opening for a temperature measurement.
17. The system of claim 1 , wherein the window is further opaque to the dominant emitted wavelengths through which the image is projected by the projector.