Adaptive control for powder fusion

A powder processing machine comprising:

• a work bed;
• a powder deposition device operable to deposit layers of powder in the work bed;
• at least one energy beam device operable to emit an energy beam with a variable beam power and scan the energy beam in a path across a first layer of the powder in the work bed with a variable beam scan rate to melt and fuse regions of the first layer of the powder to produce a first fused layer;
• a sensor operable to detect topographic characteristics in the first layer of powder and in the first fused layer and produce signals representative of the topographic characteristics by location in the work bed;
• and
• a controller in communication with the sensor to receive the signals, the controller configured to identify positive and negative topographic anomalies in the first layer of powder and in the first fused layer and,
• for a negative topographic anomaly at a location in the first layer of powder, responsively decrease the beam power, increase the beam scan rate, or both at the location of the negative topographic anomaly,
• for a positive topographic anomaly at a location in the first layer of powder, responsively increase the beam power, decrease the beam scan rate, or both at the location of the positive topographic anomaly,
• for a negative topographic anomaly at a location in the first fused layer, as the energy beam scans across a second layer of the powder that is directly over the location of the negative topographic anomaly responsively increase the beam power, decrease the beam scan rate, or both, and
• for a positive topographic anomaly at a location in the first fused layer, as the energy beam scans across a second layer of the powder that is directly over the location of the positive topographic anomaly responsively decrease the beam power, increase the beam scan rate, or both.