scholarly journals Fracture Toughness of Hybrid Components with Selective Laser Melting 18Ni300 Steel Parts

2018 ◽  
Vol 8 (10) ◽  
pp. 1879 ◽  
Author(s):  
Luis Santos ◽  
Joel de Jesus ◽  
José Ferreira ◽  
José Costa ◽  
Carlos Capela

Selective Laser Melting (SLM) is currently one of the more advanced manufacturing and prototyping processes, allowing the 3D-printing of complex parts through the layer-by-layer deposition of powder materials melted by laser. This work concerns the study of the fracture toughness of maraging AISI 18Ni300 steel implants by SLM built over two different conventional steels, AISI H13 and AISI 420, ranging the scan rate between 200 mm/s and 400 mm/s. The SLM process creates an interface zone between the conventional steel and the laser melted implant in the final form of compact tension (CT) samples, where the hardness is higher than the 3D-printed material but lower than the conventional steel. Both fully 3D-printed series and 3D-printed implants series produced at 200 mm/s of scan rate showed higher fracture toughness than the other series built at 400 mm/s of scan rate due to a lower level of internal defects. An inexpressive variation of fracture toughness was observed between the implanted series with the same parameters. The crack growth path for all samples occurred in the limit of interface/3D-printed material zone and occurred between laser melted layers.

Author(s):  
Catrin M. Davies ◽  
Ruijan Zhou ◽  
Olivia Withnell ◽  
Richard Williams ◽  
Tobias Ronneberg ◽  
...  

Selective laser melting (SLM) is a relatively new manufacturing technique which offers many benefits. However the utilisation of SLM manufactured components depends on the assurance of their integrity during operation. Fracture toughness testing (JIC) has been performed on as-built compact tension fracture mechanics samples manufactured in three orthogonal directions. When the crack growth plane was transverse to the interface of the build layers, the fracture toughness values were found to be similar to those manufactured using conventional techniques. However, the fracture toughness is significantly reduced when the crack plane is parallel to the interface of the build layers. Simple heat treatments have been performed on Charpy fracture samples and the resulting impact energy values indicate that the fracture toughness of a component may be improved by heat treatment.


Metals ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 528
Author(s):  
Chunyue Yin ◽  
Zhehao Lu ◽  
Xianshun Wei ◽  
Biao Yan ◽  
Pengfei Yan

The objective of the study is to investigate the corresponding microstructure and mechanical properties, especially bending strength, of the hypereutectic Al-Si alloy processed by selective laser melting (SLM). Almost dense Al-22Si-0.2Fe-0.1Cu-Re alloy is fabricated from a novel type of powder materials with optimized processing parameters. Phase analysis of such Al-22Si-0.2Fe-0.1Cu-Re alloy shows that the solubility of Si in Al matrix increases significantly. The fine microstructure can be observed, divided into three zones: fine zones, coarse zones, and heat-affected zones (HAZs). Fine zones are directly generated from the liquid phase with the characteristic of petaloid structures and bulk Al-Si eutectic. Due to the fine microstructure induced by the rapid cooling rate of SLM, the primary silicon presents a minimum average size of ~0.5 μm in fine zones, significantly smaller than that in the conventional produced hypereutectic samples. Moreover, the maximum value of Vickers hardness reaches ~170 HV0.2, and bending strength increases to 687.70 MPa for the as-built Al-22Si-0.2Fe-0.1Cu-Re alloys parts, which is much higher than that of cast counterparts. The formation mechanism of this fine microstructure and the enhancement reasons of bending strength are also discussed.


2021 ◽  
Vol 346 ◽  
pp. 01010
Author(s):  
Dmitry Efremov ◽  
Alla Gerasimova ◽  
Nikita Kislykh ◽  
Cristina Shaibel

The paper presents the results of studying the possibility of using the selective laser melting method for production of permanent magnets. This process allows to manufacture not only product models and prototypes, but also finished functional products by adding material layer by layer and bonding particles and layers to each other. We have considered the application areas of selective laser melting (SLM) based on powders obtained by different methods for the study. In addition, we have analyzed the traditional magnetic alloy casting technology, studied magnetic materials, and compared the powder magnet properties with standard data. We have found that the parameters of powders obtained by gas atomization are qualitatively superior to those of powders obtained using other methods, whereas the resulting magnets meet the requirements for magnets. Based on the 25Kh15KA alloy powder atomized by gas atomization, a SLM plant allows to manufacture permanent magnets with a material density of 7.59–7.55 g/cu.cm, which meets the requirements recommended by the State Standard GOST 24897-81, and to obtain the magnet properties that can be achieved using traditional metallurgical technologies.


2016 ◽  
Vol 2016 (1) ◽  
pp. 000517-000522
Author(s):  
Aarief Syed-Khaja ◽  
Christopher Kaestle ◽  
Joerg Franke

Abstract Additive manufacturing (AM) has the potential to lead significant changes in the present state-of-the-art production processes. This provides tool-free and direct manufacturing of complex geometries simultaneously integrating various functions into components. Though AM techniques are widely used in various sectors, the application into electronics production has been not yet explored. In electronics production, substrate development has high relevance due to their multi-functionality in giving the mechanical support and electrically connecting electronic components. This contribution introduces an innovative approach in the development of high-temperature substrates through additive layered manufacturing. The technique used in the investigations was selective laser melting (SLM) of copper based powder materials mainly bronze alloy and pure copper, for the generation of conductive patterns on ceramic surfaces. The process parameters for the SLM technique and the influential factors in the generation of conductive structures are discussed in detail.


Author(s):  
Mohammad Masoomi ◽  
Xiang Gao ◽  
Scott M. Thompson ◽  
Nima Shamsaei ◽  
Linkan Bian ◽  
...  

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.


2014 ◽  
Vol 783-786 ◽  
pp. 898-903 ◽  
Author(s):  
Anne Mertens ◽  
Sylvie Reginster ◽  
Quentin Contrepois ◽  
Thierry Dormal ◽  
Olivier Lemaire ◽  
...  

In this study, samples of stainless steel AISI 316L have been processed by selective laser melting, a layer-by-layer near-net-shape process allowing for an economic production of complex parts. The resulting microstructures have been characterised in details in order to reach a better understanding of the solidification and consolidation processes. The influence of the processing parameters on the mechanical properties was investigated by means of uniaxial tensile testing performed on samples produced with different main orientations with respect to the building direction. A strong anisotropy of the mechanical behaviour was thus interpreted in relation with the microstructures and the processing conditions.


2017 ◽  
Vol 50 (3) ◽  
pp. 279-282
Author(s):  
Erin Komi ◽  
Petteri Kokkonen

Additive manufacturing (AM) of metal components is characterized by the joining of material particles or feedstock to make parts described by 3D model data in typically a layer by layer fashion [1]. These modern and constantly improving manufacturing techniques inherently allow far more geometric freedom than traditional “subtractive” manufacturing processes, and thus necessitate novel approaches to component design. Careful utilization of this geometric freedom can be translated into products characterized by improved functionality and performance, simplified assemblies, are customizable, and/or lightweight [2-5]. This paper provides a brief overview design approaches, manufacturing limitations, and available tools for successful design of additive manufactured components, with special attention paid to the selective laser melting (SLM) approach.


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