scholarly journals Analysis of Microstructure and Properties of a Ti–AlN Composite Produced by Selective Laser Melting

Materials ◽  
2020 ◽  
Vol 13 (10) ◽  
pp. 2218
Author(s):  
Ryszard Sitek ◽  
Maciej Szustecki ◽  
Lukasz Zrodowski ◽  
Bartlomiej Wysocki ◽  
Jakub Jaroszewicz ◽  
...  
Keyword(s):  
Phase Composition ◽  
Chemical Composition ◽  
Selective Laser Melting ◽  
Pure Titanium ◽  
Numerical Control ◽  
Titanium Nitrides ◽  
Commercially Pure Titanium ◽  
Laser Melting ◽  
X Ray ◽  
Wide Range

Selective Laser Melting (SLM) is a manufacturing technique that is currently used for the production of functional parts that are difficult to form by the traditional methods such as casting or CNC (Computer Numerical Control) cutting from a wide range of metallic materials. In our study, a mixture of commercially pure titanium (Ti) and 15% at. aluminum nitride (AlN) was Selective Laser Melted to form three-dimensional objects. The obtained 4 mm edge cubes with an energy density that varied from 70 to 140 J/mm3 were examined in terms of their microstructure, chemical and phase composition, porosity, and Vickers microhardness. Scanning Electron Microscopy (SEM) observations of the etched samples showed inhomogeneities in the form of pores and unmelted and partly melted AlN particles in the fine-grained dendritic matrix, which is typical for titanium nitrides and titanium aluminum nitrides. The AlN particles remained unmelted in samples, but no porosity was observed in the interface area between them and the dendritic matrix. Additionally, samples fabricated with the presintering step had zones with different sizes of dendrites, suggesting a differing chemical composition of the matrix and the possibility of the formation of the phases forming an Ti–Al–N ternary system. The chemical composition in the microareas of the samples was determined using Energy Dispersive X-Ray Spectroscopy (EDS) and revealed differences in the homogeneity of the samples depending on the SLM process parameters and the additional presintering step. The phase composition, examined using X-ray Diffraction analysis (XRD), showed that samples were formed from Ti, TiN, and AlN phases. Porosity tests carried out using a computer microtomography revealed porosities in a range from 7% to 17.5%. The formed material was characterized by a relatively high hardness exceeding 700 HV0.2 over the entire cross-section, which depended on the manufacturing conditions.

Densification behavior, microstructure evolution, and wear performance of selective laser melting processed commercially pure titanium

2012 ◽  
Vol 60 (9) ◽  
pp. 3849-3860 ◽  
Author(s):  
Dongdong Gu ◽  
Yves-Christian Hagedorn ◽  
Wilhelm Meiners ◽  
Guangbin Meng ◽  
Rui João Santos Batista ◽  
...  
Keyword(s):  
Selective Laser Melting ◽  
Microstructure Evolution ◽  
Pure Titanium ◽  
Densification Behavior ◽  
Commercially Pure Titanium ◽  
Laser Melting ◽  
Wear Performance ◽  
Commercially Pure

Kinetics of Titanium Alloy Nitriding by Diode Laser

2015 ◽  
Vol 809-810 ◽  
pp. 351-356
Author(s):  
Aleksander Lisiecki
Keyword(s):  
Titanium Alloy ◽  
Diode Laser ◽  
Pure Titanium ◽  
Schematic Model ◽  
Titanium Nitrides ◽  
Commercially Pure Titanium ◽  
Nitrogen Absorption ◽  
Melt Pool ◽  
Wide Range ◽  
Kinetics Of

Based on the wide range study of laser gas nitriding (LGN) of commercially pure titanium and the titanium alloy Ti6Al4V by means of high power direct diode laser (HPDDL), the kinetics of nitrogen absorption by the melt pool and related titanium nitrides growth was analyzed. Also a schematic model of nitrogen absorption by the melt pool was proposed. According to the hypothetical model three cases of nitrogen absorption by the melt pool were be distinguished and discussed. It was found that in a case of HPDDL nitriding of the Ti6Al4V alloy the presence of a thin homogenous layer of TiNx on the top surface of melt pool affects the nitrogen absorption kinetics. The process of nitrogen desorption at the cooling stage of melt pool is inhibited by the layer of TiNx as well as by the phase transformation and titanium nitrides formation.

The effect of hatch angle rotation on parts manufactured using selective laser melting

2019 ◽  
Vol 25 (2) ◽  
pp. 289-298 ◽  
Author(s):  
Joseph Henry Robinson ◽  
Ian Robert Thomas Ashton ◽  
Eric Jones ◽  
Peter Fox ◽  
Chris Sutcliffe
Keyword(s):  
Residual Stress ◽  
Surface Roughness ◽  
Selective Laser Melting ◽  
Pure Titanium ◽  
Commercially Pure Titanium ◽  
Laser Melting ◽  
Content Type ◽  
Axial Tensile ◽  
Effects Of Rotation ◽  
Scanning Strategies

Purpose This paper aims to present an investigation into the variation of scan vector hatch rotation strategies in selective laser melting (SLM), focussing on how it effects density, surface roughness, tensile strength and residual stress. Design/methodology/approach First the optimum angle of hatch vector rotation is proposed by analysing the effect of different increment angles on distribution of scan vectors. Sectioning methods are then used to determine the effect that the chosen strategies have on the density of the parts. The top surface roughness was analysed using optical metrology, and the tensile properties were determined using uni-axial tensile testing. Finally, a novel multi-support deflection geometry was used to quantify the effects of rotation angles on residual stress. Findings The results of this research showed that the hatch rotation angle had little effect on the density, top surface roughness and strength of the parts. The greatest residual stress deflection was measured parallel to unidirectional scan vectors. The use of hatch rotations other than alternating 90° showed little benefit in lowering the magnitude of residual stresses. However, the use of rotation angles with a good suitability measure distributes stresses in all directions more evenly for certain part geometries. Research limitations/implications All samples produced in this work were made from commercially pure titanium, therefore care must be taken when applying these results to other materials. Originality/value This paper serves to increase the understanding of SLM scanning strategies and their effect on the properties of the material.

Comparison of wear properties of commercially pure titanium prepared by selective laser melting and casting processes

2015 ◽  
Vol 142 ◽  
pp. 38-41 ◽  
Author(s):  
H. Attar ◽  
K.G. Prashanth ◽  
A.K. Chaubey ◽  
M. Calin ◽  
L.C. Zhang ◽  
...  
Keyword(s):  
Selective Laser Melting ◽  
Pure Titanium ◽  
Commercially Pure Titanium ◽  
Wear Properties ◽  
Laser Melting ◽  
Commercially Pure

Selective Laser Melting of Stainless Steel with Subsequent Processing

2020 ◽  
Vol 989 ◽  
pp. 845-849
Author(s):  
A.S. Raznoschikov ◽  
D.A. Kochuyev ◽  
Anna A. Voznesenskaya
Keyword(s):  
Stainless Steel ◽  
Phase Composition ◽  
Selective Laser Melting ◽  
Hot Isostatic Pressing ◽  
Phase Changes ◽  
Laser Melting ◽  
Metallographic Study ◽  
X Ray ◽  
Isostatic Pressing ◽  
Subsequent Processing

In this work we describe the results of selective laser melting of stainless steel. The obtained samples were processed by hot isostatic pressing. Metallographic study of samples obtained after selective laser melting and hot isostatic pressing procedure was conducted. Comparison of the structure of obtained samples and a significant decrease in porosity after hot isostatic pressing was registered. The results of the phase composition by X-ray diffractometry are presented. Identified significant structural and phase changes at the study of a surface of the obtained microsections of samples, and a change in the hardness of the samples were recorded.

scholarly journals Surface Micromorphology and Structure of Stainless and Maraging Steel Obtained via Selective Laser Melting: A Mössbauer Spectroscopy Study

Metals ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1028
Author(s):  
Fredericus Linderhof ◽  
Miroslav Mashlan ◽  
Hana Doláková ◽  
Tomáš Ingr ◽  
Tatiana Ivanova
Keyword(s):  
Mössbauer Spectroscopy ◽  
Phase Composition ◽  
Selective Laser Melting ◽  
Mossbauer Spectroscopy ◽  
Three Dimensional ◽  
Surface Phase ◽  
Laser Melting ◽  
X Ray ◽  
Manufacturing Method ◽  
Mößbauer Spectroscopy

Selective laser melting (SLM) as an additive manufacturing method makes it possible to quickly produce complexly shaped three-dimensional (3D) metal specimens from a powder. This work describes how SLM affects the surface phase composition of a 3D printed specimen, as analyzed with conversion electron Mössbauer spectroscopy (CEMS), conversion X-ray Mössbauer spectroscopy (CXMS) and X-ray diffraction (XRD). Both stainless 1.4404 (CL20ES) steel and maraging 1.2709 (CL50WS) steel have been investigated. A transformation of the phase composition from the ferritic phase into an austenitic one was proven by comparing the initial CL50WS powder and the final specimen using CXMS. This transformation takes place during the SLM process. No transformation was identified in stainless steel. The differences identified via CEMS between the surface phase composition of the final non-annealed specimens and the surface of the final annealed specimens demonstrated the oxidation of the surface layer. The oxidation occurs during the annealing of the sample in surface layers less than 1 μm thick. The quality of the surface was examined using scanning electron microscopy (SEM), which presented imperfections on the face of the final specimen. Granules of the initial powder bonded to the surface of the specimen and both irregular and spherical pores were observed.

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