On productivity of laser additive manufacturing

• Published in: Journal of materials processing technology Vol. 261; pp. 213 - 232
• Main Authors: Gusarov, Andrey V., Grigoriev, Sergey N., Volosova, Marina A., Melnik, Yuriy A., Laskin, Alexander, Kotoban, Dmitriy V., Okunkova, Anna A.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 01-11-2018; Elsevier BV
• Subjects: Additive manufacturing; Alloy powders; Chemical analyzes; Defects; Diagnostics; Efficiency; Factors; Gaussian beams (optics); Laser beam; Laser beam melting; Lasers; Melting; Metal powders; Microstructure; Modeling; Monitoring; On-line systems; Organic chemistry; Parameters; Process parameters; Processing; Production methods; Productivity; Profiling; Quality; Selective laser melting; SEM; Shaping; Solid solutions; Temperature fields; Three dimensional models; Productivity; Profiling; Parameters; Diagnostics; Factors; Additive manufacturing; Modeling; Processing; Temperature fields; Selective laser melting; Laser beam; Efficiency; Shaping; Quality; SEM; Chemical analyzes; Monitoring
• ISSN: 0924-0136; 1873-4774
• DOI: 10.1016/j.jmatprotec.2018.05.033

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•The efficiency of laser additive manufacturing.•Influence of energy distribution in a laser beam.•Modulation of the laser beam with selective laser melting.•Optical diagnostics and production monitoring.•Modern tendencies for the development of 3D-printing from metal powder.
One of the most perspective methods of additive manufacturing is selective laser melting. It allows producing the parts directly from 3D-model to 3D-object from metallic powders and alloys. Nowadays the method has very low productivity, which limits its extensive use and possible application to solve a modern design problem by introducing direct and fast metal production. The solution of its productivity would allow receiving metallic 3D-objects with complex geometry in short production period.
The method was improved by the installation of laser beam profiling and online monitoring systems on the developed experimental setup. The profiler contributes to obtaining the alternative power density distributions of the laser beam. The CoCrMo powder was chosen because of its excellent melting qualities, and the initial powder was pre-treated with the purpose to get the diameter of the particles less than 20 μm. During the experiments, 3D-samples were obtained by the improved method of selective laser melting with parameters of two process windows for each of the laser beam spot. The 3D-samples were studied for the revelation of common material defects of the microstructure.
The chemicalanalyses of the samples were implemented by scanning electronic microscopy. The analyses showed that the samples of each laser beam spot had defects related to the formation of a solid solution. Application of Inverse Gaussian laser beam spot into the SLM-machine for production of 3D-objects allows producing the pieces with the values of the parameters exceeding the value for Gaussian laser beam spot in several times. The typically recommended parameters for production of the piece on the modern SLM-machine are less than 100 W for laser source power and less than 30 mm/s for scanning speed. The analytical data, presented in the article demonstrated the field of process parameters, which can give a possibility to obtain 3D-object with the parameters up to 1 kW for laser source power and up to 0.3 m/s for scanning speed. The analyses of microstructure give a possibility to conclude about no visible difference between the formation of the objects with different laser beam spots. The online video-monitoring shows that with the application of laser beam profiling system the negative effects of the selective laser melting reduces visibly.