Influence of the Direct Metal Laser Sintering Process on the Fatigue Behavior of the Ti6Al4V Alloy

2017 ◽  
Vol 891 ◽  
pp. 317-321 ◽  
Author(s):  
Adrián Bača ◽  
Radomila Konečná ◽  
Gianni Nicoletto
Keyword(s):  
Additive Manufacturing ◽  
Process Parameters ◽  
Fatigue Behavior ◽  
Laser Sintering ◽  
Ti6al4v Alloy ◽  
Process Conditions ◽  
Layer By Layer ◽  
Metal Powders ◽  
Direct Metal Laser Sintering ◽  
Post Process

Direct Metal Laser Sintering (DMLS) is additive manufacturing (AM) process that can produce near net shape parts from metal powders such as titanium alloys. DMLS is a layer by layer additive manufacturing technique based on high power fiber laser that creates solid layers from loose powder material and joins them in an additive manner. The specific DMLS process conditions, lead to a specific and complex microstructure and to mechanical properties that show a degree of directionality. It was found that microstructural characteristics are related to the building process parameters. The aim of this work is to evaluate the fatigue performance of the Ti6Al4V alloy depending on the process parameters, building orientations and post-process heat treatment.

scholarly journals Mechanical properties comparison of Ti6Al4V produced by different technologies under static load conditions

2019 ◽  
Vol 290 ◽  
pp. 08010
Author(s):  
Karolina Karolewska ◽  
Bogdan Ligaj
Keyword(s):  
Mechanical Properties ◽  
Additive Manufacturing ◽  
Selective Laser Sintering ◽  
Laser Sintering ◽  
Ti6al4v Alloy ◽  
Direct Metal Laser Sintering ◽  
Static Tests ◽  
Rolling Method ◽  
Manufacturing Techniques ◽  
Materials Used

The most commonly used technology among the additive manufacturing is Direct Metal Laser Sintering (DMLS). This process is based on selective laser sintering (SLS). The method gained its popularity due to the possibility of producing metal parts of any geometry, which would be difficult or impossible to obtain by the use of conventional manufacturing techniques. Materials used in the elements manufacturing process are: titanium alloys (e.g. Ti6Al4V), aluminium alloy AlSi10Mg, etc. Elements printed from Ti6Al4V titanium alloy find their application in many industries. Details produced by additive technology are often used in medicine as skeletal, and dental implants. Another example of the DMLS elements use is the aerospace industry. In this area, the additive manufacturing technology produces, i.a. parts of turbines. In addition to the aerospace and medical industries, DMLS technology is also used in motorsport for exhaust pipes or the gearbox parts. The research objects are samples for static tests. These samples were made of Ti6Al4V alloy by the DMLS method and the rolling method from a drawn rod. The aim of the paper is the mechanical properties comparative analysis of the Ti6Al4V alloy produced by the DMLS method under static loading conditions and microstructure analysis of this material.

Effect of Build Direction in Direct Metal Laser Sintering (DMLS) of Inconel 718 on Microstructure and Mechanical Behavior

2019 ◽  
Author(s):  
Sachin Alya ◽  
Chaitanya Vundru ◽  
Ramesh Singh ◽  
Khushahal Thool ◽  
Indradev Samajdar ◽  
...  
Keyword(s):  
Additive Manufacturing ◽  
Mechanical Behavior ◽  
Inconel 718 ◽  
Laser Sintering ◽  
Thermal Gradients ◽  
Layer By Layer ◽  
Direct Metal Laser Sintering ◽  
Powder Bed ◽  
Grain Orientations ◽  
End Use

Abstract Additive manufacturing (AM) technology is gaining enormous popularity in the manufacturing industries. The continuous improvements made in the AM processes features development of 3D metallic prototypes as well as fully functional end-use components. Direct Metal Laser Sintering (DMLS) is a pre-placed powder bed based technique, in which a thin layer of powder is place over the build tray and the areas need to be sintered are exposed to the laser. In the current work the microstructural and mechanical behavior of Inconel 718 parts produced by DMLS are investigated. As the DMLS produces parts in a layer by layer fashion, the orientation of parts with respect to the build direction is an important criterion. Microstructure and mechanical properties of the produce differs depending upon the orientation. This paper emphasize on the variation of grain sizes and grain orientations developed in the components built with different orientations. Another common issue with the additive manufacturing is the development of the residual stresses in the components arising due to the differential thermal gradients experienced during processing. The variation of the residual stress generated in the produced parts has also been characterized and modeled.

Game Theoretic Modelling Approach for Optimizing Direct Metal Laser Sintering Process Parameters Using Artificial Neural Network

2020 ◽  
Author(s):  
Suchana Jahan ◽  
Hazim El-Mounayri
Keyword(s):  
Neural Network ◽  
Artificial Neural Network ◽  
Additive Manufacturing ◽  
Process Parameters ◽  
Laser Sintering ◽  
Optimization Techniques ◽  
Direct Metal Laser Sintering ◽  
Game Theoretic ◽  
Artificial Neural ◽  
Modelling Approach

Abstract Additive Manufacturing, also known as Rapid Prototyping and 3D Printing is a three-dimensional fabrication process, executed by adding materials in layers. Among many different classes of AM processes, Direct Metal Laser Sintering is a widely used metal part manufacturing method. The design, planning and implementation of overall DMLS process and its process parameters are yet to be optimized. To be able to render minimum defects as well as higher quantity of production, it is essential to apply ever developing computer technologies, data storage capabilities and optimization techniques. Typically, the defects on any 3D printed part can alter mechanical properties and shorten its durability. To minimize the defects and produce good quality parts at a mass level, has been a challenge in additive manufacturing industry. In this paper, a framework is presented to utilize game theoretic modelling approach to optimize DMLS process parameters. Online monitoring of DMLS process can identify defects of printed layers and correlate them with temperature signatures. An Artificial Neural Network is trained to predict printing defects and process parameters. predicted model can be further used in a game theoretic playoff matrix to identify the most optimal combination or configuration of DMLS process parameters to minimize defects and maximize the production quantity. The proposed method can also be applied in different domains of additive and advanced manufacturing.

High Cycle Fatigue Life of Ti6Al4V Alloy Produced by Direct Metal Laser Sintering

2016 ◽  
Vol 258 ◽  
pp. 522-525 ◽  
Author(s):  
Radomila Konečná ◽  
Gianni Nicoletto ◽  
Adrián Bača ◽  
Ludvík Kunz
Keyword(s):  
Fatigue Life ◽  
High Cycle Fatigue ◽  
Fatigue Testing ◽  
Fatigue Behavior ◽  
Fatigue Crack Initiation ◽  
Laser Sintering ◽  
Ti6al4v Alloy ◽  
Cycle Fatigue ◽  
Direct Metal Laser Sintering ◽  
Stress Relieving

High cycle fatigue life of Ti6Al4V alloy specimens manufactured by Direct Metal Laser Sintering (DMLS) was experimentally determined. The DMLS fabrication process was characterized by a 400 W laser power and 50 μm layer melted thickness. Post-fabrication heat treatment consisted in stress relieving for 3 h at 720 °C in vacuum with subsequent cooling in argon atmosphere. Fatigue testing of specimens oriented in three different directions with respect to the material build direction was performed with the aim to examine the influence of the layered microstructure on the fatigue behavior. Results of measurement of surface roughness, metallographic examinations of the layered material and fractographic investigation of the fatigue fracture surfaces were employed in the discussion of fatigue crack initiation in DMLS fabricated Ti6Al4V alloy.

Metallographic Characterization and Fatigue Damage Initiation in Ti6Al4V Alloy Produced by Direct Metal Laser Sintering

2017 ◽  
Vol 891 ◽  
pp. 311-316 ◽  
Author(s):  
Radomila Konečná ◽  
Gianni Nicoletto ◽  
Adrián Bača ◽  
Ludvík Kunz
Keyword(s):  
Fatigue Behavior ◽  
Fatigue Crack Initiation ◽  
Structural Heterogeneity ◽  
Cyclic Stress ◽  
Laser Sintering ◽  
Fatigue Tests ◽  
Ti6al4v Alloy ◽  
Direct Metal Laser Sintering ◽  
Damage Initiation ◽  
Complex Process

Direct Metal Laser Sintering (DMLS) is a complex process where a part is build-up by localized melting of gas atomized powder layers by a concentrated laser beam followed rapid solidification. The microstructure of DMLS produced material is substantially different from that of conventionally manufactured materials, although the ultimate strength is similar. However, yield strength and elongation and especially fatigue behavior may vary considerably according to the process parameters and post fabrication heat treatment because they affect structural heterogeneity, porosity content, residual stresses, and surface conditions. Fatigue tests of DMLS Ti6Al4V alloy are interpreted in the light of a thorough metallographic and fractographic investigation. The fatigue crack initiation for three different cyclic stress directions with respect to build direction is determined by fractography.

scholarly journals Recent Studies and Developments in Titanium Biomaterials

2020 ◽  
Vol 321 ◽  
pp. 02004
Author(s):  
M. Ikedaa ◽  
M. Ueda ◽  
M. Ninomi
Keyword(s):  
Health Care ◽  
Additive Manufacturing ◽  
Titanium Alloys ◽  
Young’S Modulus ◽  
Young's Modulus ◽  
Layer By Layer ◽  
Metal Powders ◽  
Alloy Development ◽  
Dental Surgery ◽  
Artificial Bones

Titanium and its alloys have a high specific strength, excellent corrosion resistance, and good biocompatibility. Therefore, these alloys are adopted as raw materials for artificial bones and joints. Furthermore, these alloys are used as materials for dental surgery. In the development of alloy design, beta-type titanium alloys that possess a lower Young’s modulus than other types of titanium alloys, e.g., Ti-6Al-4V alpha-beta-type alloys, are being actively investigated worldwide. Based on these studies, titanium-niobium-tantalum and zirconium system alloys were developed. For example, Ti-29Nb-13Ta-4.6Zr alloy has a low Young’s modulus, excellent biocompatibility, and improved mechanical properties. Many researchers are actively investigating surface modifications and surface treatments. Additive manufacturing, namely 3D printing, wherein metal powders are piled up layer by layer to produce goods without a mold, has attracted attention in many fields, including manufacture of implants, especially porous structural implants with a low Young’s modulus. It is very important that titanium and its alloys be applied to health-care goods, e.g., wheelchairs and prostheses. Therefore, we herein consider four topics: alloy development, coating and surface modification, additive manufacturing, and health care applications.

Investigation on the Effect of Process Parameters on Hardness of Components Produced by Direct Metal Laser Sintering (DMLS)

2012 ◽  
Vol 488-489 ◽  
pp. 1414-1418 ◽  
Author(s):  
C.D. Naiju ◽  
K. Annamalai ◽  
P.K. Manoj ◽  
K.M. Ayaz
Keyword(s):  
Process Parameters ◽  
Statistical Design ◽  
Laser Sintering ◽  
Optimum Process ◽  
Direct Metal Laser Sintering ◽  
Significant Extent ◽  
Statistical Design Of Experiments ◽  
Layer Manufacturing ◽  
Manufacturing Technologies ◽  
Hatch Spacing

Direct metal laser sintering (DMLS) is one of the methods in layer manufacturing technologies by which metal powder can be directly used to produce both prototype and production tools. The components manufactured by DMLS should have essential hardness for its application in the industry. This study was carried out to determine the optimum process parameters influencing the hardness of the components produced by DMLS. Sintering speed, hatch spacing, post contouring, infiltration and hatch type are the process parameters taken up for study. Statistical design of experiments using Taguchi’s orthogonal array was employed for this study. The experimental data obtained were analyzed using ANOVA. From the results, it is found that one of the process parameters; scan spacing affects the hardness of the parts produced by this technology to a significant extent.

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