Decarburization of stainless steel during selective laser melting and its influence on Young's modulus, hardness and tensile strength

2015 ◽  
Vol 647 ◽  
pp. 58-61 ◽  
Author(s):  
Xiao Zhao ◽  
Bo Song ◽  
Yuanjie Zhang ◽  
Xiaomeng Zhu ◽  
Qingsong Wei ◽  
...  
Keyword(s):  
Tensile Strength ◽  
Stainless Steel ◽  
Young’S Modulus ◽  
Selective Laser Melting ◽  
Young's Modulus ◽  
Laser Melting

Analytical Solution and Experimental Study of Effective Young's Modulus of Selective Laser Melting-Fabricated Lattice Structure With Triangular Unit Cells

2018 ◽  
Vol 140 (9) ◽  
Author(s):  
Jie Niu ◽  
Hui Leng Choo ◽  
Wei Sun ◽  
Sui Him Mok
Keyword(s):  
Analytical Solution ◽  
Young’S Modulus ◽  
Selective Laser Melting ◽  
Triangular Lattice ◽  
Young's Modulus ◽  
Numerical Results ◽  
Lattice Structures ◽  
Shape Parameters ◽  
Laser Melting ◽  
Unit Cells

Research on materials, design, processing, and manufacturability of parts produced by additive manufacturing (AM) has been investigated significantly in the past. However, limited research on tensile behavior of cellular lattice structures by AM was carried out. In this paper, effective tensile Young's modulus, E*, of triangular lattice structures was determined. Firstly, analytical solution was derived based on Euler–Bernoulli beam theory. Then, numerical results of E* were obtained by finite element analysis (FEA) for triangular lattice structures classified by three shape parameters. The effects of side length, L, beam thickness, t, and height, h, on E* were investigated individually. FEA results revealed that there is a relationship between E* and the relative density and shape parameters. Among them, t has the most significant effect on E*. Numerical results were also compared with the results from modified general function for cellular structures and modified formula for triangular honeycomb. The E* predicted by the proposed analytical solution shows the best agreement with the numerical results. Finally, tensile tests were carried out using AlSi10 Mg triangular lattice structures manufactured by selective laser melting (SLM) process. The experimental results show that both analytical and numerical solutions are able to predict E* with good accuracy. In the future, the proposed solution can be used to design lightweight structures with triangular unit cells.

Evaluation of Physicomechanical Properties of Ti-45Nb Specimens Obtained by Selective Laser Melting

2017 ◽  
Vol 743 ◽  
pp. 9-12
Author(s):  
Zhanna G. Kovalevskaya ◽  
Margarita A. Khimich ◽  
Andrey V. Belyakov
Keyword(s):  
Young’S Modulus ◽  
Selective Laser Melting ◽  
Laser Power ◽  
Young's Modulus ◽  
Scanning Speed ◽  
Physicomechanical Properties ◽  
Optical Methods ◽  
Laser Melting ◽  
Average Value ◽  
Hardness Tester

Porosity, values of nanohardness and Young’s modulus of the specimens obtained with the method of selective laser melting were measured with optical methods, scanning electron microscopy and Nano Hardness Tester NHT-S-AX-000X device for measuring physicomechanical properties. Ti-45wt%Nb powder obtained with mechanical alloying was used for selective laser melting. The results have shown that increased heat input due to the laser power growth up to 80 W and scanning speed decrease down to 40 mm/s decreases the porosity of the specimen. The nanohardness average value is not sensitive to the changes of scanning modes in the investigated range. The Young’s modulus decreases with energy input increase.

Manufacturing of Porous Biomaterials for Dental Implant Applications through Selective Laser Melting

2012 ◽  
Vol 535-537 ◽  
pp. 1222-1229 ◽  
Author(s):  
Francesco Cardaropoli ◽  
Vittorio Alfieri ◽  
Fabrizia Caiazzo ◽  
Vincenzo Sergi
Keyword(s):  
Mechanical Properties ◽  
Young’S Modulus ◽  
Dental Implants ◽  
Selective Laser Melting ◽  
Young's Modulus ◽  
Bulk Material ◽  
Total Porosity ◽  
Porous Metals ◽  
Efficient Technology ◽  
Laser Melting

The paper discusses the possibility of manufacturing dental implants through Selective Laser Melting (SLM) of a Ti-6Al-4V alloy powder. Among all possible biomaterials, this alloy is widely used in biomedical applications due to high biocompatibility. Selective Laser Melting allows to obtain biomaterials with peculiar characteristics in terms of porosity gradient, roughness, customized geometry, and mechanical properties. Influence of input process parameters on porosity and analysis of Selective Laser Melting capabilities in implant dentistry have been focused. Porosity is a key parameter in dental implants as it affects stiffness, which is related to Young’s modulus. Ti-6Al-4V bulk material presents a Young’s modulus of 110 GPa, whereas the bone one ranges from 10 to 26 GPa. The relative difference of mechanical properties causes the phenomenon of stress shielding, which has a detrimental effect on the longevity of dental implants. Total porosity is important in reducing the effective modulus of porous metals. Biomaterials specimens obtained during experimental phase have been examined in terms of porosity (in inverse ratio to relative density), microstructure, microhardness and roughness. According to test results discussed in this paper, Selective Laser Melting is proved to be an efficient technology for the construction of Ti-6Al-4V dental implants, because biomaterials with adequate properties can be obtained changing processing parameters. Other fabrication techniques fail to produce biomaterials for dental implants with the desired features.

scholarly journals 316L Stainless Steel Manufactured by Selective Laser Melting and Its Biocompatibility with or without Hydroxyapatite Coating

Metals ◽  
2018 ◽  
Vol 8 (7) ◽  
pp. 548 ◽  
Author(s):  
Jiapeng Luo ◽  
Xiao Jia ◽  
Ruinan Gu ◽  
Peng Zhou ◽  
Yongjiang Huang ◽  
...  
Keyword(s):  
Tensile Strength ◽  
Stainless Steel ◽  
Selective Laser Melting ◽  
316L Stainless Steel ◽  
Primary Dendrite ◽  
Sol Gel ◽  
Scanning Speed ◽  
Steel Matrix ◽  
Laser Melting ◽  
Relative Growth

To fabricate metallic 316L/HA (hydroxyapatite) materials which meet the requirements of an implant’s mechanical properties and bioactivity for its function as human bone replacement, selective laser melting (SLM) has been employed in this study to prepare a 316L stainless steel matrix, which was subsequently covered with a hydroxyapatite (HA) coating using the sol-gel method. High density (98.9%) as-printed parts were prepared using a laser power of 230 W and a scanning speed of 800 mm/s. Austenite and residual acicular ferrite existed in the microstructure of the as-printed 316L stainless steel, and the sub-grain was uniform, whose primary dendrite spacing was around 0.35 μm. The as-printed 316L stainless steel showed the highest Vickers hardness, elastic modulus, and tensile strength at ~ (~ means about; same applies below unless stated otherwise) 247 HV, ~214.2 GPa, and ~730 MPa, respectively. The elongation corresponding to the highest tensile strength was ~38.8%. The 316L/HA structure, measured by the Relative Growth Rate (RGR) value, exhibited no cell cytotoxicity, and presented better biocompatibility than the uncoated as-printed and as-cast 316L samples.

Effects of laser power on the microstructure and mechanical properties of 316L stainless steel prepared by selective laser melting

2017 ◽  
Vol 31 (16-19) ◽  
pp. 1744015 ◽  
Author(s):  
Zeng Zheng ◽  
Lianfeng Wang ◽  
Biao Yan
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Stainless Steel ◽  
Selective Laser Melting ◽  
Laser Power ◽  
Laser Scanning ◽  
316L Stainless Steel ◽  
Laser Melting ◽  
Scanning Strategy ◽  
Microstructure And Mechanical Properties

Selective laser melting (SLM) was used to prepare 316L stainless steel parts and the effects of laser power on the microstructure and mechanical properties of the final products were studied. With increasing applied laser power, the defects of as-built parts were reduced greatly and the as-built parts presented a highest relative density of 99.1%. The tensile strength of samples was significantly improved from 321 ± 10 MPa to 722 ± 10 MPa. The microhardness was homogeneous; the residual stresses in the samples were tensile, which were higher in the section perpendicular to the laser scanning strategy. The probable reasons for this phenomenon were proposed.

Heat Treatment on Microstructure and Tensile Strength of 316 Stainless Steel by Selective Laser Melting

2015 ◽  
Vol 42 (4) ◽  
pp. 0406003
Author(s):  
丁利 Ding Li ◽  
李怀学 Li Huaixue ◽  
王玉岱 Wang Yudai ◽  
黄志涛 Huang Zhitao
Keyword(s):  
Heat Treatment ◽  
Tensile Strength ◽  
Stainless Steel ◽  
Selective Laser Melting ◽  
Laser Melting ◽  
316 Stainless Steel

scholarly journals Effects of Laser Spot Size on the Mechanical Properties of AISI 420 Stainless Steel Fabricated by Selective Laser Melting

Materials ◽  
2021 ◽  
Vol 14 (16) ◽  
pp. 4593
Author(s):  
Xi-Huai Yang ◽  
Chong-Ming Jiang ◽  
Jeng-Rong Ho ◽  
Pi-Cheng Tung ◽  
Chih-Kuang Lin
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Stainless Steel ◽  
Energy Density ◽  
Selective Laser Melting ◽  
Spot Size ◽  
Laser Spot ◽  
Laser Melting ◽  
Laser Spot Size ◽  
Aisi 420

The purpose of this study is to investigate the effects of laser spot size on the mechanical properties of AISI 420 stainless steel, fabricated by selective laser melting (SLM), process. Tensile specimens were built directly via the SLM process, using various laser spot diameters, namely 0.1, 0.2, 0.3, and 0.4 mm. The corresponding volumetric energy density (EV) is 80, 40, 26.7, and 20 J/mm3, respectively. Experimental results indicates that laser spot size is an important process parameter and has significant effects on the surface roughness, hardness, density, tensile strength, and microstructure of the SLM AISI 420 builds. A large laser spot with low volumetric energy density results in balling, un-overlapped defects, a large re-heated zone, and a large sub-grain size. As a result, SLM specimens fabricated by the largest laser spot diameter of 0.4 mm exhibit the roughest surface, lowest densification, and lowest ultimate tensile strength. To ensure complete melting of the powder and melt pool stability, EV of 80 J/mm3 proves to be a suitable laser energy density value for the given SLM processing and material system.

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