Forming a single crystal structure during additive manufacturing

An apparatus, comprising:

• a powder bed;
• a recoater head configured to recoat the powder bed with unmelted metal powder;
• a tool actuator coupled to the recoater head;
• and
• a tool coupled to the tool actuator, wherein the apparatus is configured to:
• spread, utilizing the recoater head, the layer of unmelted metal powder on the powder bed;
• melt a portion of the layer in a shape of a cross-section of a corresponding layer of a plurality of layers of the additively manufactured 3D printed part;
• remove, utilizing the tool, metal powder adjacent to a first melted edge of the shape;
• remelt at least one of:
• the first melted edge, or the portion of the layer in the shape of the cross-section of the corresponding layer of the plurality of layers of the additively manufactured 3D printed part;
• and
• repeat the spread, the melt, the remove, and the remelt at each successive layer of the plurality of layers of the additively manufactured 3D printed part.

A method of additively manufacturing a three-dimensional (3D) printed part, comprising:

• spreading a layer of unmelted metal powder on a powder bed;
• melting a portion of the layer in a shape of a cross-section of a corresponding layer of a plurality of layers of the additively manufactured 3D printed part, the portion of the layer having a melted edge;
• repeating the spreading and the melting of L−1 successive layers of metal powder corresponding to L−1 respective layers of the plurality of layers of the additively manufactured 3D printed part, where L is an integer greater than 1;
• and
• removing, following the spreading and melting of a topmost layer, utilizing a first tool, a polycrystalline shell adjacent to the melted edge of each respective layer to a depth of L layers relative to the topmost layer.

An apparatus, comprising:

• a powder bed;
• a recoater head configured to recoat the powder bed with an unmelted metal powder;
• a tool actuator coupled to the recoater head;
• and
• a tool coupled to the tool actuator, wherein the apparatus is configured to:
• spread, utilizing the recoater head, a layer of the unmelted metal powder on the powder bed;
• melt a portion of the layer in a shape of a cross-section of a corresponding layer of a plurality of layers of the additively manufactured 3D printed part, the portion of the layer having a melted edge;
• repeat the spreading and the melting of L−1 successive layers of metal powder corresponding to L−1 respective layers of the plurality of layers of the additively manufactured 3D printed part, where L is an integer greater than 1;
• and
• remove, following the spreading and the melting of a topmost layer, utilizing the tool, a polycrystalline shell adjacent to the melted edge of each respective layer to a depth of L layers relative to the topmost layer.