Laser-assisted controlled heating hotspot mitigation for 3D printing
A system and method of three-dimensional printing that includes heating a portion of a build surface by impinging multiple laser pulses onto the build surface in a time controlled pattern to provide a desired heated build surface prior to depositing a molten material onto the build surface. The time controlled pattern of laser pulses includes at least one heating period and at least one cooling period, and the time for the cooling period is determined by the cooling time of the build surface material, and the temperature differences between the original temperature of the build surface and the desired temperature of the build surface material.
1 . A method of three-dimensional printing comprising:
providing a molten material to a printhead of a three-dimensional printer;
measuring an original temperature of a build surface;
determining a temperature difference between the original temperature of the build surface and a desired temperature of the build surface;
determining a number of laser pulses to achieve the temperature difference; and
calculating an increase in temperature needed during each of the laser pulses;
heating the build surface up to the desired temperature of the build surface temperature by impinging more than one laser pulses onto the build surface in a time controlled pattern; and
depositing the molten material onto the build surface that was heated to the desired temperature to form a layer.
2 . The method of claim 1 further comprising:
identifying a portion of the layer as a subsequent build surface;
heating the subsequent build surface by impinging more than one laser pulses onto the subsequent build surface; and
depositing the molten material onto the heated subsequent build surface.
3 . The method of claim 1 , wherein the molten material is aluminum or an aluminum alloy.
4 . The method of claim 1 , wherein the laser pulses have an irradiance of from about 1000 W/cm 2 to about 10,000 W/mm 2 .
5 . The method of claim 1 , wherein the laser pulses are impinged onto a surface area of the build surface of between about 0.01 mm to about 5 mm in diameter.
6 . A method of stepwise laser-assisted heating in a three-dimensional printing process comprising:
estimating an original temperature on a build surface;
calculating a temperature difference between the original temperature of the build surface and a desired temperature of the build surface;
determining a number N of incremental steps to increase the original temperature on the build surface to the desired temperature of the build surface;
calculating a temperature change needed during each of the N incremental steps using a formula (1/(N−1)) multiplied by the calculated temperature difference; and
heating the build surface for the determined number N of incremental steps using a laser.
7 . The method of claim 6 , wherein the incremental steps include a time controlled pattern of heating periods of time and cooling periods of time.
8 . The method of claim 7 , wherein the cooling periods of time is less than a 100% cooling time of the build surface.
9 . The method of claim 7 , wherein the heating periods of time are determined by a time needed to increase to the calculated temperature change needed during each of the N incremental steps.
10 . The method of claim 6 , wherein the laser has an irradiance of from about 1000 W/mm 2 to about 10,000 W/mm 2 .
11 . The method of claim 6 , wherein the laser heats the build surface by impinging one or more laser pulses onto a surface area of the build surface of between 0.01 mm to about 5 mm in diameter.
12 . The method of claim 8 , wherein the cooling time period of a build surface is a 50% cooling time of the build surface.
13 . The method of claim 6 , further comprising depositing a molten material to form a layer onto the build surface that was heated to the desired temperature.
14 . A method of three-dimensional printing comprising:
providing a molten material to a printhead of a three-dimensional printer;
measuring an original temperature of a build surface;
determining a temperature difference between the original temperature of the build surface and a desired temperature of the build surface;
heating the build surface up to the desired temperature of the build surface temperature by impinging more than one laser pulses onto the build surface in a time controlled pattern; and
depositing the molten material onto the build surface that was heated to the desired temperature to form a layer,
wherein the time controlled pattern includes one or more of heating time periods when the laser pulse is turned on, and one or more cooling time periods in between each one or more heating time period when the laser pulse is turned off.
15 . The method of claim 14 further comprising:
identifying a portion of the layer as a subsequent build surface;
heating the subsequent build surface by impinging more than one laser pulses onto the subsequent build surface; and
depositing the molten material onto the heated subsequent build surface.
16 . The method of claim 14 , wherein the cooling time period is less than a 100% cooling time of the build surface.
17 . The method of claim 16 , wherein the cooling time period of a build surface is a 50% cooling time of the build surface.
18 . The method of claim 14 , wherein the molten material is aluminum or an aluminum alloy.
19 . The method of claim 14 , wherein the laser pulses have an irradiance of from about 1000 W/cm 2 to about 10,000 W/mm 2 .
20 . The method of claim 14 , wherein the laser pulses are impinged onto a surface area of the build surface of between about 0.01 mm to about 5 mm in diameter.