Selective laser melting (slm) additive manufacturing

A selective laser melting (SLM) additive manufacturing device, comprising:

• a material forming laser to form layers of a three-dimensional (3D) object;
• an electromagnetic wave source to produce a detection beam;
• an interferometer interposed between the electromagnetic wave source and a target detection area;
• a photodetector to detect displacement measuring interference between electromagnetic waves from the electromagnetic wave source and reflected electromagnetic waves from the target detection area through the interferometer;
• and
• control logic to cause the detection beam to follow a print path of the material forming laser,
• wherein the detection beam is placed on a re-cooled portion of a layer of the 3D object formed by the material forming laser.

A method of monitoring for defects within a selective laser melting (SLM) additive manufacturing process, comprising:

• with an electromagnetic wave source, projecting a detection beam onto a target detection area through an interferometer;
• controlling the detection beam to follow a print path of a material forming laser, the detection beam being projected onto a cooled portion of a layer of the 3D object formed by the material forming laser;
• and
• with a photodetector, detecting displacement measuring interference between electromagnetic waves from the electromagnetic wave source and reflected electromagnetic waves from the target detection area through the interferometer.