scholarly journals Effects of Heat Treatment of Selective Laser Melting Printed Ti-6Al-4V Specimens on Surface Texture Parameters and Cell Attachment

2021 ◽  
Vol 11 (5) ◽  
pp. 2234
Author(s):  
Pei-Wen Peng ◽  
Jen-Chang Yang ◽  
Wei-Fang Lee ◽  
Chih-Yuan Fang ◽  
Chun-Ming Chang ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Selective Laser Melting ◽  
Surface Texture ◽  
Large Scale ◽  
Cell Attachment ◽  
Characteristic Length ◽  
Laser Melting ◽  
Heat Treated ◽  
Texture Parameters ◽  
Areal Surface

Selective laser melting (SLM) is extensively used for fabricating metallic biomedical products. After 3D printing, it is almost always advisable to apply a heat treatment to release the internal tensions or optimize the mechanical properties of the printed parts. The aim of this paper is to investigate the effects of heat treatment of SLM printed Ti-6Al-4V (Ti64) circular specimens on the areal surface texture parameters and cell attachment. Areal surface texture parameters, including the arithmetic mean height (Sa), root-mean-square height (Sq), skewness (Ssk), and kurtosis (Sku) were characterized. In addition, wavelet-based multi-resolution analysis was applied to investigate the characteristic length scales of untreated and heat-treated Ti64 specimens. In this study, the vertical distance between the highest and lowest position of cell attachment for each sampling area was defined as DH. Results showed that an increase in the periodic characteristic length scale was primarily due to the formation of large-scale aggregations of Ti64 metal powder particles on the heat-treated surface. In addition, MG-63 cells preferred lying in concave hollows; in heat-treated specimens, values of DH statistically significantly decreased from 31.6 ± 4.2 to 8.8 ± 2.8 μm, while Sku decreased from 3.3 ± 1.4 to 2.6 ± 0.6, indicating a strong influence of Sku on cell attachment.

Mechanical Behaviour of Gas Nitrided Ti6Al4V Bars Produced by Selective Laser Melting

2016 ◽  
Vol 704 ◽  
pp. 225-234 ◽  
Author(s):  
Peter Franz ◽  
Aamir Mukhtar ◽  
Warwick Downing ◽  
Graeme Smith ◽  
Ben Jackson
Keyword(s):  
Heat Treatment ◽  
Selective Laser Melting ◽  
Nitrided Layer ◽  
Xrd Analysis ◽  
Compound Layer ◽  
Processing Parameters ◽  
Heat Treatments ◽  
Laser Melting ◽  
Gas Nitriding ◽  
Heat Treated

Gas atomized Ti-6Al-4V (Ti64) alloy powder was used to prepare distinct designed geometries with different properties by selective laser melting (SLM). Several heat treatments were investigated to find suitable processing parameters to strengthen (specially to harden) these parts for different applications. The results showed significant differences between tabulated results for heat treated billet Ti64 and SLM produced Ti64 parts, while certain mechanical properties of SLM Ti64 parts could be improved by different heat treatments using different processing parameters. Most heat treatments performed followed the trends of a reduction in tensile strength while improving ductility compared with untreated SLM Ti64 parts.Gas nitriding [GN] (diffusion-based thermo-chemical treatment) has been combined with a selected heat treatment for interstitial hardening. Heat treatment was performed below β-transus temperature using minimum flow of nitrogen gas with a controlled low pressure. The surface of the SLM produced Ti64 parts after gas nitriding showed TiN and Ti2N phases (“compound layer”, XRD analysis) and α (N) – Ti diffusion zones as well as high values of micro-hardness as compared to untreated SLM produced Ti64 parts. The microhardness profiles on cross section of the gas nitrided SLM produced samples gave information about the i) microhardness behaviour of the material, and ii) thickness of the nitrided layer, which was investigated using energy dispersive spectroscopy (EDS) and x-ray elemental analysis. Tensile properties of the gas nitrided Ti64 bars produced by SLM under different conditions were also reported.

Influence of Post Heat Treatment on Microstructure and Mechanical Property of Ti6Al4V Parts Produced by Selective Laser Melting

2017 ◽  
Vol 898 ◽  
pp. 1312-1317 ◽  
Author(s):  
Hong Yu Ding ◽  
Pei Kun Qiu ◽  
Yuan Fei Han ◽  
Zhong Gang Sun ◽  
Jie Huang ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Selective Laser Melting ◽  
Room Temperature ◽  
Preliminary Investigation ◽  
Side View ◽  
Laser Melting ◽  
Post Heat Treatment ◽  
Heat Treated ◽  
Top View ◽  
Microstructure And Mechanical Property

A preliminary investigation of the post heat treatment for Ti6Al4V tensile specimens fabricated via selective laser melting (SLM) are reported. The resultant microstructure and mechanical behavior at room temperature, normal and parallel to the building direction, was investigated in detail. Moreover, the as-prepared samples were compared with the samples post heat treated at 600°C~800°C for 2 h. It was found that the SLM fabricated samples consisted of long columnar original β grains together with parallel acicular α' martensitic structure dominated in the β matrix, which was observed in the side view, and fully equaixed β grains pattern in the top view. The post heat treatment did not completely disrupt the layered structure, but leading to the acicular α' martensites decomposing into α platelets distributed in a metastable β matrix. Ultimate tensile strength and elongation were analyzed and explained based on the microstructure evolution. After post heat treatment, an increase in elongation was observed for the tensile samples, inducing more ductile like morphology after fracture.

scholarly journals Microstructure and Mechanical Properties of Al–(12-20)Si Bi-Material Fabricated by Selective Laser Melting

Materials ◽  
2019 ◽  
Vol 12 (13) ◽  
pp. 2126 ◽  
Author(s):  
Shikai Zhang ◽  
Pan Ma ◽  
Yandong Jia ◽  
Zhishui Yu ◽  
Rathinavelu Sokkalingam ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Tensile Strength ◽  
Selective Laser Melting ◽  
Dimensional Accuracy ◽  
High Dimensional ◽  
Laser Melting ◽  
Geometrical Complexity ◽  
Microstructure And Mechanical Properties ◽  
Heat Treated

In this study, a combination of Al–12Si and Al–20Si (Al–(12-20)Si) alloys was fabricated by selective laser melting (SLM) as a result of increased component requirements such as geometrical complexity and high dimensional accuracy. The microstructure and mechanical properties of the SLM Al–(12-20)Si in as-produced as well as in heat-treated conditions were investigated. The Al–(12-20)Si interface was in the as-built condition and it gradually became blurry until it disappeared after heat treatment at 673 K for 6 h. This Al–(12-20)Si bi-material displayed excellent mechanical properties. The hardness of the Al–20Si alloy side was significantly higher than that of the Al–12Si alloy side and the disparity between both sides gradually decreased and tended to be consistent after heat treatment at 673 K for 6 h. The tensile strength and elongation of the Al–(12-20Si) bi-material lies in between the Al–12Si and Al–20Si alloys and fracture occurs in the Al–20Si side. The present results provide new insights into the fabrication of bi-materials using SLM.

scholarly journals Effect of Heat Treatment on Microstructure and Mechanical Properties of a Selective Laser Melting Processed Ni-Based Superalloy GTD222

Materials ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 3668
Author(s):  
Tian Xia ◽  
Rui Wang ◽  
Zhongnan Bi ◽  
Guoliang Zhu ◽  
Qingbiao Tan ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Additive Manufacturing ◽  
Selective Laser Melting ◽  
Treatment Process ◽  
Heat Treatment Process ◽  
Laser Melting ◽  
Microstructure Characteristics ◽  
Microstructure And Mechanical Properties ◽  
Heat Treated

Additive manufacturing (AM) of nickel-based superalloys is of high interest for application in complex hot end parts. However, it has been widely suggested that the microstructure-properties of the additive manufacturing processed superalloys are not yet fully clear. In this study, the GTD222, an important superalloy for high-temperature hot-end part, were prepared using selective laser melting and then subjected to heat treatment. The microstructure evolution of the GTD222 was investigated and the mechanical properties of heat treated GTD222 were tested. The results have shown that the grain size of the heat treated GTD222 was close to its as-built counterparts. Meanwhile, a large amount of γ’ and nano-scaled carbides were precipitated in the heat treated GTD222. The microstructure characteristics implied that the higher strength of the heat treated GTD222 can be attributed to the γ’ and nano-scaled carbides. This study provides essential microstructure and mechanical properties information for optimizing the heat treatment process of the AM processed GTD222.

Assessment of Heat Treatment Effect on AlSi10Mg by Selective Laser Melting through Indentation Testing

2019 ◽  
Vol 813 ◽  
pp. 171-177 ◽  
Author(s):  
Giacomo Maculotti ◽  
Gianfranco Genta ◽  
Massimo Lorusso ◽  
Maurizio Galetto
Keyword(s):  
Selective Laser Melting ◽  
Melt Spinning ◽  
Ad Hoc ◽  
Indentation Test ◽  
Al Alloy ◽  
Laser Melting ◽  
Heat Treated ◽  
Processing Properties ◽  
Am Processes ◽  
Metal Additive

Selective Laser Melting (SLM) is one of the leader metal Additive Manufacturing (AM) processes thanks to its capability of coupling freeform design and environmental and economical sustainability to high mechanical properties. AlSi10Mg is a light weight Al-alloy with interesting processing properties and enhanced strength thanks to the presence of Mg, which, hence, finds application in several industrial fields. Furthermore, SLM allows overcoming those design constraints set by casting and melt spinning; however, SLM AlSi10Mg components require to be heat treated, both to strengthen the material and to engineer the microstructure. In this work, in order to assess the effectiveness of heat treatments on AlSi10Mg by SLM, an ad hoc analysis procedure based on statistical tools is applied in combination with indentation characterisation tests. In particular, to achieve full scale characterisation, traditional Brinell hardness and Instrumented Indentation Test (IIT) in macro and nano-range are considered. In particular, IIT is applied both at the lower end of macro range to provide consistency and statistically investigate relationship with Brinell scale and in the nano-range, enabling local, i.e. grain, and surface properties to be characterised.

Effect of laser rescanning on Ti6Al4V microstructure during selective laser melting

2020 ◽  
pp. 095440542097609
Author(s):  
Weipeng Duan ◽  
Meiping Wu ◽  
Jitai Han
Keyword(s):  
Wear Resistance ◽  
Titanium Alloy ◽  
Selective Laser Melting ◽  
Human Body ◽  
High Impact ◽  
Laser Melting ◽  
Heat Treated ◽  
Volume Porosity ◽  
Biomedical Field

TC4, which is one of the most widely used titanium alloy, is frequently used in biomedical field due to its biocompatible. In this work, selective laser melting (SLM) was used to manufacture TC4 parts and the printed parts were heat-treated using laser rescanning technology. The experimental results showed that laser rescanning had a high impact on the quality of SLMed part, and a different performance on wear resistance can be found on the basis. It can be seen that the volume porosity of the sample was 7.6 ± 0.5% without using any further processing technology. The volume porosity of the sample processed using laser rescanning strategy was decreased and the square-framed rescanning strategy had a relative optimal volume porosity (1.5 ± 0.3%) in all these five samples. With the further decreasing of volume porosity, the wear resistance decreased at the same time. As its excellent bio-tribological properties, the square-framed rescanning may be a potential suitable strategy to forming TC4 which used in human body.

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