Progress on Investigation of Pores During Selective Laser Melting of Metal Powders and Future Work Discussion

2011 ◽  
Vol 291-294 ◽  
pp. 3088-3094
Author(s):  
Jin Hui Liu ◽  
Wen Juan Xie ◽  
Qing Song Wei ◽  
Li Wang
Keyword(s):  
Selective Laser Melting ◽  
Physical And Mechanical Properties ◽  
Porous Metal ◽  
Complex Structures ◽  
Metal Powders ◽  
Porous Metals ◽  
Laser Melting ◽  
Metal Structures ◽  
Metal Parts ◽  
Future Work

Pores are always considered as a kind of defect during manufacturing metal parts via many conventional processes. But porous metals have outstanding physical and mechanical properties which providing them double natures of function and structure, and are applied in many fields of science and technology. Selective laser melting (SLM), developed within current years, has the advantages of producing metal parts with complex structures, and can be used to manufacture complex structures of any kind theoretically. A new method of making porous complicated metal structures via SLM is put forward. Then, the meaning of this method, research advance and future work discussion are presented in this paper, which lays a method foundation for future study and build a new field for both porous metal parts and SLM technology.

On Formation and Estimation of Pores during Selective Laser Melting of Single-Phase Metal Powders

2011 ◽  
Vol 338 ◽  
pp. 94-101
Author(s):  
Jin Hui Liu ◽  
Wen Juan Xie ◽  
Sheng Bing Xiao ◽  
Wei Ling Zhao ◽  
Jia Zhang
Keyword(s):  
Selective Laser Melting ◽  
Formation Mechanism ◽  
Single Phase ◽  
Porous Metal ◽  
Processing Parameters ◽  
Metal Powders ◽  
Porous Metals ◽  
Laser Melting ◽  
Metal Parts ◽  
Powder Particles

Porous metals are applied in many more fields than other porous materials. Pores in porous metal parts manufactured by selective laser melting (SLM) should not be regarded as defects but favorable characters because they are the main composition of porous metal parts. Therefore, fully densification is not the only target in forming metal parts via SLM. The formation mechanism of pores in SLM is studied mathematically in this article, and mathematical model is built to describe the formation mechanism. It is concluded that the shape of pores and the porosity of parts are the function of SLM processing parameters and the diameter of powder particles. Pores can be controlled and estimated by adjusting processing parameters and the nature of forming materials. Porous metal parts produced by SLM can be applied in many more fields owing that SLM technology is flexible to change the shape of these part and the nature of materials.

scholarly journals Thermodynamic Behavior of Fe-Mn and Fe-Mn-Ag Powder Mixtures during Selective Laser Melting

Metals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 234
Author(s):  
Jakob Kraner ◽  
Jožef Medved ◽  
Matjaž Godec ◽  
Irena Paulin
Keyword(s):  
Selective Laser Melting ◽  
Manganese Oxides ◽  
Elevated Temperatures ◽  
Manganese Content ◽  
Chemical Compositions ◽  
Metal Powders ◽  
Laser Melting ◽  
Powder Mixtures ◽  
Ε Martensite ◽  
The Impact

Additive manufacturing is a form of powder metallurgy, which means the properties of the initial metal powders (chemical composition, powder morphology and size) impact the final properties of the resulting parts. A complete characterization, including thermodynamic effects and the behavior of the metal powders at elevated temperatures, is crucial when planning the manufacturing process. The analysis of the Fe-Mn and Fe-Mn-Ag powder mixtures, made from pure elemental powders, shows a high susceptibility to sintering in the temperature interval from 700 to 1000 °C. Here, numerous changes to the manganese oxides and the αMn to βMn transformation occurred. The problems of mechanically mixed powders, when using selective laser melting, were highlighted by the low flowability, which led to a less controllable process, an uncontrolled arrangement of the powder and a large percentage of burnt manganese. All this was determined from the altered chemical compositions of the produced parts. The impact of the increased manganese content on the decreased probability of the transformation from γ-austenite to ε-martensite was confirmed. The ε-martensite in the microstructure increased the hardness of the material, but at the same time, its magnetic properties reduce the usefulness for medical applications. However, the produced parts had comparable elongations to human bone.

scholarly journals Determination of geometric accuracy and surface roughness of small parts of circular and square sections, obtained depending on the printer location in the working space using selective laser melting technology from steel grade 12KH18N10T

2019 ◽  
pp. 59-67
Author(s):  
I. V. Gorbatov ◽  
Y. A. Orlov ◽  
V. A. Antiufeev ◽  
T. V. Telgerekova ◽  
N. Y. Orlova
Keyword(s):  
Selective Laser Melting ◽  
Physical And Mechanical Properties ◽  
Steel Grade ◽  
Geometric Accuracy ◽  
Laser Melting ◽  
Working Space ◽  
Properties Of Materials ◽  
Number Of Publications ◽  
Small Parts

The introduction of additive technologies for the manufacture of parts will significantly improve the efficiency and mobility of production. The technology of selective laser melting has the greatest accuracy in the manufacture of metal and alloyed parts. There are a number of publications on the physical and mechanical properties of such products, which often exceed the properties of materials obtained by traditional technology, but there is no data on the geometric accuracy of manufacturing. This paper provides explicit data on geometric accuracy, depending on various factors.

Current Status and Progress on Technology of Selective Laser Melting of Metal Parts

2018 ◽  
Vol 55 (1) ◽  
pp. 011401 ◽  
Author(s):  
杨永强 Yang Yongqiang ◽  
陈杰 Chen Jie ◽  
宋长辉 Song Changhui ◽  
王迪 Wang Di ◽  
白玉超 Bai Yuchao
Keyword(s):  
Selective Laser Melting ◽  
Current Status ◽  
Laser Melting ◽  
Metal Parts

Investigation of Physical and Mechanical Properties of Samples Grown by Selective Laser Melting of Iron Powder

2019 ◽  
Vol 11 ◽  
pp. 95-100
Author(s):  
Ivan Shakirov ◽  
Anton Zhukov ◽  
Pavel Kuznetsov ◽  
Vitaliy Bobyr' ◽  
Tatiana Fedina ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Iron Powder ◽  
Selective Laser Melting ◽  
Physical And Mechanical Properties ◽  
Laser Melting

Modeling, Simulation and Experimental Validation of Heat Transfer During Selective Laser Melting

2015 ◽  
Author(s):  
Mohammad Masoomi ◽  
Xiang Gao ◽  
Scott M. Thompson ◽  
Nima Shamsaei ◽  
Linkan Bian ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Mechanical Properties ◽  
Selective Laser Melting ◽  
Heat Fluxes ◽  
Transient Temperature ◽  
Thermal Gradients ◽  
Layer By Layer ◽  
Metal Powders ◽  
Laser Melting ◽  
Powder Bed

Selective Laser Melting (SLM), a laser powder-bed fusion (PBF-L) additive manufacturing method, utilizes a laser to selectively fuse adjacent metal powders. The powders are aligned in a bed that moves vertically to allow for layer-by-layer part construction-Process-related heat transfer and thermal gradients have a strong influence on the microstructural features, and subsequent mechanical properties, of the parts fabricated via SLM. In order to understand and control the heat transfer inherent to SLM, and to ensure high quality parts with targeted microstructures and mechanical properties, comprehensive knowledge of the related energy and mass transport during manufacturing is required. In this study, the transient temperature distribution within and around parts being fabricated via SLM is numerically simulated and the results are provided to aid in quantify the SLM heat transfer. In order to verify simulation output, and to estimate actual thermal gradients and heat transfer, experiments were separately conducted within a SLM machine using a substrate with embedded thermocouples. The experiments focused on characterizing heat fluxes during initial deposition on an initially-cold substrate and during the fabrication of a thin-walled structure built via stainless steel 17-4 powders. Results indicate that it is important to model heat transfer thorough powder bed as well as substrate.

Optical Monitoring and Numerical Simulation of Temperature Distribution at Selective Laser Melting of Ti6Al4V Alloy

2015 ◽  
Vol 828-829 ◽  
pp. 474-481 ◽  
Author(s):  
Ivan Zhirnov ◽  
Ina Yadroitsava ◽  
Igor Yadroitsev
Keyword(s):  
Numerical Simulation ◽  
Temperature Distribution ◽  
Selective Laser Melting ◽  
Ti6al4v Alloy ◽  
Advanced Technology ◽  
Temperature Fields ◽  
Optical Monitoring ◽  
Metal Powders ◽  
Laser Melting ◽  
Ir Camera

Selective laser melting (SLM) is a modern method for producing objects with complex shape and fine structures in one working cycle from metal powders. Combination of the advanced technology of SLM with unique properties of Ti6Al4V alloy allows creating complex 3D objects for medicine or aerospace industry. Since properties of SLM parts depend on the geometrical characteristics of tracks and their cohesion, optical monitoring is actually used to for control the process. Temperature gradient determines the microstructure and mechanical properties of the SLM part, so studies about temperature fields are primarily important. On-line monitoring during laser scanning of Ti6Al4V alloy and formation of a single track in real-time with high-speed IR camera was studied. Numerical simulation allowed estimation the temperature distribution during processing. Conclusion regarding control system based on the online monitoring of deviations of the signal from IR camera during the SLM process was done.

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