Journal ArticleDOI
Effect of defects on the constant-amplitude fatigue behavior of as-built Ti-6Al-4V alloy produced by laser powder bed fusion process: Assessing performance with metallographic analysis and micromechanical simulations
Reads0
Chats0
TLDR
In this article , the influence of various process parameters on the mechanical behavior (including tensile strength, strain-to-failure and constant-amplitude fatigue performance) of as-built Ti-6Al-4V alloy, produced via laser powder bed fusion (L-PBF) process, is demonstrated using complementary information obtained from mechanical (uniaxial tensile and fatigue) tests, fractography analysis, metallographic analysis and micromechanical simulations.Abstract:
The influence of various process parameters on the mechanical behavior (including tensile strength, strain-to-failure and constant-amplitude fatigue performance) of as-built Ti-6Al-4V alloy, produced via laser powder bed fusion (L-PBF) process, is demonstrated using complementary information obtained from mechanical (uniaxial tensile and fatigue) tests, fractography analysis, metallographic analysis and micromechanical simulations. Four different build conditions were considered such that the laser power and velocity were varied for each build while holding the build orientation, hatch spacing, layer thickness, laser spot size and hatch rotation constant. The volumetric energy densities (E) of the four unique builds were: 33 J/mm3, 66 J/mm3, 130 J/mm3 and 180 J/mm3, respectively. Two coupons per build were subjected to constant-amplitude fatigue loading while one coupon per build was subject to uniaxial tensile loading at room temperature. Coupons belonging to Builds 1 and 2 (corresponding to E values of 33 J/mm3 and 66 J/mm3, respectively) had considerably longer fatigue lives compared to coupons from Builds 3 and 4 (corresponding to E values of 130 J/mm3 and 180 J/mm3, respectively). To reconcile the relative lifing capability of the four builds, fractography, two-dimensional (2D) pore analysis, and multiscale finite-element simulation campaigns are detailed. Collectively, these exercises underscore the centrality of pore clustering on the fatigue performance of the builds. Moreover, they highlight the role that microstructural character (viz. grain orientation with respect to loading) plays on the accumulation of plastic strain in the vicinity of pores. Specifically, it is demonstrated that a pore embedded in a grain favorably oriented for slip accumulates a significant amount of plastic strain compared to one embedded in a grain not favorably oriented for slip. Comparing the relative performance and defect character of the four builds, this study suggests that both pore spacing and relative grain hardness act in concert with other fatigue-limiting characteristics including pore size, shape and distance to free surface. read more
Citations
More filters
Journal ArticleDOI
Hot isostatic pressing of laser powder-bed-fused 304L stainless steel under different temperatures
TL;DR: In this paper , the effect of hot isostatic pressing temperature on material characteristics and mechanical properties of additively manufactured austenitic stainless steel was investigated, where the authors comprehensively investigated material characteristics (porosity, residual stress, microstructures, phase composition, and inclusion), mechanical properties (microhardness, tensile properties, and fatigue properties), and deformation behaviors of LPBF 304L stainless steel (ASS) subjected to HIP process with different temperatures.
Journal ArticleDOI
Corrosion behavior and mechanism of laser powder bed fusion produced CoCrW in an acidic NaCl solution
TL;DR: In this article , the corrosion behavior and mechanism of the laser powder bed fusion (L-PBF) produced CoCrW were investigated in 0.9 wt% NaCl solution with a pH of 2.
Journal ArticleDOI
A point field driven approach to process metrics based on laser powder bed fusion additive manufacturing models and in situ process monitoring
Samuel J.A. Hocker,H. Richter,Peter W. Spaeth,Andrew R. Kitahara,Joseph N. Zalameda,Edward H. Glaessgen +5 more
TL;DR: In this article , a point field driven AM model-based process metric (AM-PM) approach was proposed to calculate melt track resolved process conditions with maximal computational speed. But the AM-PM approach is not suitable for modeling and monitoring process conditions.
References
More filters
Journal ArticleDOI
NIH Image to ImageJ: 25 years of image analysis
TL;DR: The origins, challenges and solutions of NIH Image and ImageJ software are discussed, and how their history can serve to advise and inform other software projects.
Journal ArticleDOI
Heat treatment of Ti6Al4V produced by Selective Laser Melting: Microstructure and mechanical properties
TL;DR: In this paper, the effect of several heat treatments on the microstructure and mechanical properties of Ti6Al4V processed by Selective Laser Melting (SLM) is studied.
Journal ArticleDOI
Metal Additive Manufacturing: A Review of Mechanical Properties
John J. Lewandowski,Mohsen Seifi +1 more
TL;DR: A review of published data on the mechanical properties of additively manufactured metallic materials can be found in this paper, where the additive manufacturing techniques utilized to generate samples covered in this review include powder bed fusion (eBM, SLM, DMLS) and directed energy deposition (eBF3).
Journal ArticleDOI
Effects of defects, inclusions and inhomogeneities on fatigue strength
Yukitaka Murakami,Masahiro Endo +1 more
TL;DR: In this article, the effects of defects, inclusions and inhomogeneities on the fatigue strength of metals are reviewed, from the Isibasi model and the Frost model to recent models based on fracture mechanics.
Journal ArticleDOI
DREAM.3D: A Digital Representation Environment for the Analysis of Microstructure in 3D
TL;DR: The approach to building a generalized representation strategy for digital microstructures and the barriers encountered when trying to integrate a set of existing software tools to create an expandable codebase are discussed.