System and method for additively manufacturing an object
A method of additively manufacturing an object includes successively forming a plurality of powder layers by depositing powder over a build platform using a powder-deposition apparatus. The method also includes successively forming a binder shell by bonding select regions of each one of the plurality of powder layers before forming each successive one of the plurality of powder layers using a binder-delivery apparatus. The binder shell encloses a portion of the powder. The method further includes densifying the portion of the powder bound by the binder shell using a consolidation apparatus.
1 . An additive manufacturing system comprising:
a build platform;
a recoater configured to deposit powder;
a base positioned over the build platform;
a printhead actuator coupled to the base;
a printhead coupled to and movable relative to the base by the printhead actuator, the printhead is configured to selectively deposit binder to the powder;
a tamper actuator coupled to the base;
a tamper coupled to and movable relative to the base by the tamper actuator, the tamper is configured to densify the powder; and
a controller programmed to cause:
the recoater to successively form a plurality of powder layers over the build platform;
the printhead to successively form a binder shell by applying the binder to bond select regions of each one of the plurality of powder layers before the recoater forms each successive one of the plurality of powder layers such that the binder shell is formed of bonded powder and the binder shell encloses an entirety of a powder core formed of unbonded powder; and
the tamper to selectively pack a portion of the unbonded powder bound within the binder shell during layer-by-layer formation.
2 . The additive manufacturing system of claim 1 , further comprising a vibrator coupled to the build platform and configured to compact the portion of the powder bound by the binder shell.
3 . The additive manufacturing system of claim 2 , wherein the vibrator comprises an ultrasonic vibration element configured to generate ultrasonic vibrations.
4 . The additive manufacturing system of claim 1 , wherein the tamper comprises a tamping head configured to consecutively compress sections of the portion of the powder bound by the binder shell.
5 . The additive manufacturing system of claim 1 , wherein the tamper comprises a plurality of tamping pins configured to simultaneously compress an entirety of the portion of the powder bound by the binder shell.
6 . The additive manufacturing system of claim 4 ,
further comprising a vibrator coupled to the build platform and configured to compact a portion of the powder bound by the binder shell.
7 . The additive manufacturing system of claim 1 , wherein the printhead configured to apply droplets of the binder at the select regions of each successive one of the plurality of powder layers under direction of the controller.
8 . The additive manufacturing system of claim 1 , wherein the recoater comprises at least one of a powder roller, a blade, or a powder sprayer.
9 . The additive manufacturing system of claim 1 , further comprising a sintering furnace configured to burn away the binder of the bonded powder and to consolidate the bonded powder and the unbonded powder.
10 . An additive manufacturing system comprising:
a power chamber;
a build platform;
a recoater configured to transfer powder from the powder chamber to the build platform;
a base positioned over the build platform;
a printhead actuator coupled to the base;
a printhead coupled to and movable relative to the base by the printhead actuator, the printhead is configured to deliver binder to the powder;
a tamper actuator coupled to the base;
a vibrator tamper coupled to and movable relative to the base by the tamper actuator, the tamper is configured to densify the powder; and
a controller programmed to cause:
the recoater to successively form a plurality of powder layers over the build platform;
the printhead to successively form a binder shell by bonding select regions of each one of the plurality of powder layers before the recoater forms each successive one of the plurality of powder layers such that the binder shell is formed of bonded powder and the binder shell encloses an entirety of a powder core formed of unbonded powder; and
the tamper to compact a portion of the unbound powder bound within the binder shell during layer-by-layer formation.
11 . The additive manufacturing system of claim 10 , further comprising a vibrator onfigured to compact the portion of the powder bound by the binder shell.
12 . The additive manufacturing system of claim 11 , wherein the vibrator is coupled to the build platform.
13 . The additive manufacturing system of claim 11 , wherein the vibrator comprises an ultrasonic vibration element configured to generate ultrasonic vibrations.
14 . The additive manufacturing system of claim 11 , wherein the tamper comprises a plurality of tamping pins configured to simultaneously compress an entirety of the unbonded powder bound by the binder shell.
15 . The additive manufacturing system of claim 10 , wherein the tamper comprises a tamping head configured to consecutively compress sections of the unbonded powder bound by the binder shell.
16 . The additive manufacturing system of claim 10 , wherein the tamper comprises a plurality of tamping pins configured to simultaneously compress an entirety of the unbonded powder bound by the binder shell.
17 . The additive manufacturing system of claim 10 , wherein the printhead is configured to apply droplets of the binder at the select regions of each successive one of the plurality of powder layers.
18 . The additive manufacturing system of claim 10 , further comprising a sintering furnace configured to burn away the binder of the bonded powder and to consolidate the bonded powder and the unbonded powder.
19 . The additive manufacturing system of claim 10 , wherein the recoater comprises at least one of a powder roller, a blade, or a powder sprayer.
20 . The additive manufacturing system of claim 5 , further comprising a vibrator coupled to the build platform and configured to compact a portion of the powder bound by the binder shell.