Online monitoring method of laser additive manufacturing process based on multi-source heterogeneous data

Abstract

The invention discloses an online monitoring method of a laser additive manufacturing process based on multi-source heterogeneous data. The online monitoring method of the laser additive manufacturingprocess based on the multi-source heterogeneous data comprises the steps of 1, building laser energy distribution; 2, obtaining a medium vibration speed; 3, obtaining the maximum surface temperatureof a powder bed; 4, obtaining the width of a molten pool; 5, building a multi-field coupling thermodynamic model during a laser melting process; 6, sparse-coding the multi-source heterogeneous data; and 7, obtaining an online monitoring model. According to the online monitoring method of the laser additive manufacturing process based on the multi-source heterogeneous data provided by the invention, the laser additive manufacturing process can be monitored in real time and controlled, so that process parameters are automatically adjusted when micro defects appear so as to eliminate the defects,the part forming quality is further improved, and the actual precision and reliability demands are met.

Description

technical field [0001] The invention belongs to the technical field of sensors and monitoring, and more specifically relates to an online monitoring method for laser additive manufacturing driven by big data. Background technique [0002] Additive manufacturing (3D printing / rapid prototyping) technology is gradually changing people's traditional lifestyles and production methods, and is considered to promote the third industrial revolution with its characteristics of rapidity, customization, digitalization and networking. Laser additive manufacturing technology is currently one of the metal additive manufacturing processes with the widest application range and the greatest practical significance. This technology uses high-energy laser beams to melt or sinter powders according to a predetermined path, and then form them after cooling and solidification. It has significant advantages in the manufacture of difficult-to-machine parts such as complex structures, free-form surface...

AI Technical Summary

Problems solved by technology

[0003] However, because the laser additive manufacturing process is accompanied by complex physical and chemical processes, the formed parts have a large temperature gradient and thermal stress, and the forming process is prone to defects such as spheroidization, pores, and cracks, which affect the accuracy and reliability of the formed parts. Formed parts are easy to deform and crack, and lack of process control of forming quality, which seriously hinders the application of laser additive manufacturing technology

[0004] However, due to the complex dynamic characteristics of the laser additive manufacturing process, the high difficulty of sensor installation, and the lack of understanding of related physical processes, real-time monitoring and process control of the laser additive manufacturing process are not easy to carry out, and the monitoring models are limited. Most of them use infrared temperature information. Modeling with Machining Quality

However, the error of online temperature measurement is relatively large, and the mechanism of defects in the powder melting or sintering process is complex, and the reliability of quality measurement only based on temperature information is insufficient, and related research still needs to be further advanced.

[0005] Although post-processing such as sandblasting and heat treatment can obtain better surface finish and reduce fracture and delamination, post-processing will bring about changes in the size of parts. For parts with complex internal structures, key functional parts, and precision parts, post-processing method will no longer apply

Images