Experimental Study of Direct Metal Laser Sintering: High Cycle Fatigue Life and Process Parameters

2021 ◽  
Author(s):  
Sudhir Kaul ◽  
Riley Seyffert
Keyword(s):  
Experimental Study ◽  
Fatigue Life ◽  
Process Parameters ◽  
High Cycle Fatigue ◽  
Laser Sintering ◽  
Cycle Fatigue ◽  
Direct Metal Laser Sintering

Experimental Study of Direct Metal Laser Sintering: High Cycle Fatigue Life and Process Parameters

2020 ◽  
Author(s):  
Riley Seyffert ◽  
Sudhir Kaul
Keyword(s):  
Fatigue Life ◽  
Layer Thickness ◽  
Process Parameters ◽  
High Cycle Fatigue ◽  
Laser Sintering ◽  
Bending Test ◽  
Cycle Fatigue ◽  
Direct Metal Laser Sintering ◽  
Build Time ◽  
Scan Speed

Abstract Direct Metal Laser Sintering (DMLS) is a relatively new manufacturing process in additive manufacturing (AM) that fuses powdered metal by using a high-powered laser. Although this process allows manufacturing prototypes without requiring specific tooling, it is challenging to use this process for manufacturing high volume production parts since complex shapes can take a significant amount of build time. Furthermore, manufactured parts also need some amount of post-processing to remove the support material that may be required due to the layer-by-layer build process. This study investigates three process parameters that could be optimized to substantially reduce production time. These three parameters are as follows: build layer thickness, laser scan speed, and laser hatch distance. In order to evaluate the influence of these parameters, manufactured parts made of AISI 316L Stainless Steel are tested for fatigue life and static strength. A three-point bending test is used as per ASTM E466. While none of the three parameters is seen to significantly influence ultimate tensile strength, results indicate that build layer thickness is a significant process parameter that directly affects fatigue life. Furthermore, the interaction between build layer thickness and laser scan speed is found to be statistically significant for high cycle fatigue. However, laser scan speed and laser hatch distance are seen to be statistically insignificant for fatigue life. The initial results of this study indicate that process parameters of DMLS need to be selected judiciously in order to minimize build time while maintaining structural integrity.

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.

Fatigue Behavior of Aerospace Al-Cu, Al-Li and Al-Mg-Si Sheet Alloys

2015 ◽  
Vol 1099 ◽  
pp. 1-8
Author(s):  
Nikolaos D. Alexopoulos ◽  
Vangelis Migklis ◽  
Stavros K. Kourkoulis ◽  
Zaira Marioli-Riga
Keyword(s):  
Mechanical Properties ◽  
Experimental Study ◽  
Fatigue Life ◽  
High Cycle Fatigue ◽  
Endurance Limit ◽  
Fatigue Behavior ◽  
Cycle Fatigue ◽  
Constant Amplitude ◽  
6Xxx Series ◽  
Fatigue Endurance

In the present work, an experimental study was performed to characterize and analyze the tensile and constant amplitude fatigue mechanical behavior of several aluminum alloys, namely 2024 (Al-Cu), 2198 (Al-Li) and 6156 (Al-Mg-Si). Al-Li alloy was found to be superior of 2024 in the high cycle fatigue and fatigue endurance limit regimes, especially when considering specific mechanical properties. Alloy 6156 was found to have superior constant amplitude fatigue performance that the respective 6xxx series alloys; more than 15% higher endurance limit was noticed against 6061 and almost 30% higher than 6082. Alloy 6156 presented only a marginal increase in fatigue life for the HCF regime.

High-cycle fatigue tests of pretensioned concrete beams

PCI Journal ◽  
2022 ◽  
Vol 67 (1) ◽  
Author(s):  
Jörn Remitz ◽  
Martin Empelmann
Keyword(s):  
Fatigue Life ◽  
High Cycle Fatigue ◽  
Concrete Beams ◽  
Fatigue Behavior ◽  
Fatigue Tests ◽  
Design Methods ◽  
Test Results ◽  
Cycle Fatigue ◽  
Pretensioned Concrete ◽  
Current Design

Pretensioned concrete beams are widely used as bridge girders for simply supported bridges. Understanding the fatigue behavior of such beams is very important for design and construction to prevent fatigue failure. The fatigue behavior of pretensioned concrete beams is mainly influenced by the fatigue of the prestressing strands. The evaluation of previous test results from the literature indicated a reduced fatigue life in the long-life region compared with current design methods and specifications. Therefore, nine additional high-cycle fatigue tests were conducted on pretensioned concrete beams with strand stress ranges of about 100 MPa (14.5 ksi). The test results confirmed that current design methods and specifications overestimate the fatigue life of embedded strands in pretensioned concrete beams.

High Cycle Fatigue Damage Evaluation of Steel Pipelines Based on Microhardness Changes During Cyclic Loads: Part II

2018 ◽  
Author(s):  
Geovana Drumond ◽  
Bianca Pinheiro ◽  
Ilson Pasqualino ◽  
Francine Roudet ◽  
Didier Chicot
Keyword(s):  
Fatigue Life ◽  
Fatigue Damage ◽  
High Cycle Fatigue ◽  
Steel Structures ◽  
New Method ◽  
Microplastic Deformation ◽  
Surface Phenomenon ◽  
Cyclic Loads ◽  
Cycle Fatigue ◽  
Indentation Tests

The hardness of a material shows its ability to resist to microplastic deformation caused by indentation or penetration and is closely related to the plastic slip capacity of the material. Therefore, it could be significant to study the resistance to microplastic deformations based on microhardness changes on the surface, and the associated accumulation of fatigue damage. The present work is part of a research study being carried out with the aim of proposing a new method based on microstructural changes, represented by a fatigue damage indicator, to predict fatigue life of steel structures submitted to cyclic loads, before macroscopic cracking. Here, Berkovich indentation tests were carried out in the samples previously submitted to high cycle fatigue (HCF) tests. It was observed that the major changes in the microhardness values occurred at the surface of the material below 3 μm of indentation depth, and around 20% of the fatigue life of the material, proving that microcracking is a surface phenomenon. So, the results obtained for the surface of the specimen and at the beginning of the fatigue life of the material will be considered in the proposal of a new method to estimate the fatigue life of metal structures.

Sign in / Sign up

Export Citation Format

Share Document