Additive manufacturing system using a pulse modulated laser for two-dimensional printing
A method of additive manufacture is disclosed. The method may include providing a powder bed and directing a shaped laser beam pulse train consisting of one or more pulses and having a flux greater than 20 kW/cm 2 at a defined two dimensional region of the powder bed. This minimizes adverse laser plasma effects during the process of melting and fusing powder within the defined two dimensional region.
1. A method of additive manufacture, the method comprising:
performing preliminary halo test;
providing a powder bed;
directing a shaped laser beam pulse train including one or more pulses and having a flux greater than 20 kW/cm 2 at a defined two-dimensional region of the powder bed; and
melting and fusing powder within the defined two-dimensional region;
wherein the method further comprises a calibration step that includes adjusting at least one of a laser beam energy, pulse width, or area of the defined two-dimensional region in response to a detected area of a halo formed by the preliminary halo test.
2. The method of claim 1 , wherein less than 10% by weight of powder particles in the powder bed are ejected into areas outside the defined two-dimensional region.
3. The method of claim 1 , wherein the shaped laser beam pulse train is provided by a system including an arbitrary pulsed laser source, at least one pre-amplifier, and at least one power amplifier.
4. The method of claim 1 , wherein the flux is between 20 kW/cm 2 and 10 GW/cm 2 at the powder bed.
5. The method of claim 1 , wherein the defined two-dimensional region of the powder bed is between 0.000025 cm 2 and 1,000 cm 2 .
6. The method of claim 1 , thickness of the powder bed is between at least one of 1-2000 μm range, a 25-250 μm range, and 50-100 μm range.
7. The method of claim 1 , wherein the powder used is <100,000 um in diameter using a pulsed laser intensity <10 GW/cm 2 at the powder bed.
8. The method of claim 1 , wherein the powder used is <500 um in diameter using a pulse intensity >20 kW/cm 2 at the powder bed.
9. The method of claim 1 , wherein a laser temporal pulsewidth of the shaped laser beam pulse train is between 20 nanoseconds and 100 microseconds.
10. The method of claim 1 , wherein a laser pulse train is utilized with number of pulses greater than 1.
11. The method of claim 1 wherein a laser pulse peak power of the shaped laser beam pulse train is adjusted as a function of time.
12. A method of additive manufacture, the method comprising:
performing preliminary halo test;
providing a powder bed;
directing a shaped laser beam pulse train including one or more pulses and having a flux greater than 20 kW/cm 2 at a defined two-dimensional region of the powder bed; and
melting and fusing powder within the defined two-dimensional region;
wherein the method further comprises a calibration step that includes adjusting at least one of pulse shape, number of pulses, or pulse peak power as a function of time in response to detected area of a halo formed by the preliminary halo test.
13. The method of claim 1 , further comprising A method of additive manufacture, the method comprising:
performing preliminary halo test;
providing a powder bed;
directing a shaped laser beam pulse train including one or more pulses and having a flux greater than 20 kW/cm 2 at a defined two-dimensional region of the powder bed; and
melting and fusing powder within the defined two-dimensional region;
wherein the method further comprises a step of detecting a halo area formed by the preliminary halo test, with detected radius of the halo area being set greater than 50 microns beyond the defined two-dimensional region.