Adaptive path for additive manufacturing using a laser source

A method of determining a trajectory followed by a laser beam for selective additive manufacture of a three-dimensional object, the method comprising:

• (I) an emitting step including emitting, via a laser source, a laser beam toward a layer of powder for manufacturing the three-dimensional object;
• (II) a determining step comprising:
• (a) a first determining step including determining, on a predetermined reference path, a plurality of reference points,
• (b) a second determining step including determining a plurality of adjacent points located on a same side of the predetermined reference path, each adjacent point being associated with a reference point and being such that a simulated adjacent melt zone that surrounds the adjacent point and a simulated reference melt zone that surrounds the reference point have an overlap corresponding to a fraction of a transverse width of the simulated reference melt zone that is comprised between a predetermined minimum fraction and a predetermined maximum fraction, the second determining step comprising successively, for each adjacent point in one direction of travel of a trajectory of the laser beam, the following steps:
• (1) estimating, for a reference point associated with an adjacent point, a transverse width of a reference simulated melt zone;
• (2) determining an initial position of the adjacent point, a distance separating the initial position of the adjacent point from a position of the reference point being equal to a product of the transverse width of the reference simulated melt zone and of a predetermined target degree of overlap, the adjacent point being placed with respect to the reference point in a direction that is orthogonal to the predetermined reference path at the reference point, comprised in a plane of the layer of powder and directed from the predetermined reference path toward an adjacent path;
• and
• (3) carrying out secondary steps, which are as follows:
• (i) estimating an initial transverse width of a simulated adjacent melt zone;
• (ii) estimating an overlap between the reference simulated melt zone and the adjacent simulated melt zone;
• and
• (iii) repeating the secondary steps while modifying the initial position of the adjacent point if the estimated overlap corresponds to a fraction of the simulated reference melt zone less than a predetermined minimum fraction or greater than a predetermined maximum fraction;
• (c) a third determining step including determining an adjacent path linking the plurality of adjacent points;
• and
• (d) repeating the first determining step, the second determining step, and the third determining step in a loop using the adjacent path determined as a new reference path, so as to determine, on each iteration, a new adjacent path among the plurality of adjacent paths, until all adjacent paths to be travelled by the laser beam in the layer of powder have been determined, the plurality of adjacent paths that have been determined defining a determined trajectory, which is followed by the laser beam;
• (III) a storing or transmitting step including storing or transmitting the determined trajectory to the control unit of a selective additive manufacturing apparatus;
• (IV) an estimating step including estimating the transverse width of a zone being a total width in a direction transverse to a direction of scanning of the laser beam;
• and
• (V) a moving step, occurring after the determining step (II), including moving the laser beam along the determined trajectory made up of the plurality of adjacent paths to cause the layer of powder to melt according to the determined trajectory to optimize overlapping of melt zones for melting the layer of powder such that non-melted portions of the layer of powder are avoided to prevent defects in the three-dimensional object, the determined trajectory being directed by a computer simulation that provides a desired path of the laser beam, wherein the moving step includes controlling the laser source, via a control unit, to emit the laser beam onto the layer of powder according to the determined trajectory.