Review of Detection Analysis and Control of Temperature Fieldin Laser Additive Manufacturing

Laser metal additive manufacturing, which is referred to a near-net-shaping process, builds metal parts by rapid melting, solidification and layer-wise cladding. The large temperature gradient in laser additive manufacturing process causes the thermal stress, thermal deformation, metallurgical defects and microstructure degradation of the part; therefore, the detection, analysis and control of the temperature fields are always the key problems of metal additive manufacturing. The review is presented of detection, analysis and control technologies of the temperature fields in additive manufacturing at home and abroad, including the finite element simulation, the in-process detection based on the infrared camera and pyrometer, the closed-loop control and the substrate preheating control. The advantages and disadvantages of the present techniques of detection, analysis and control of the temperature fields are compared, and the future trend is analyzed.