A5019782713- Additive Manufacturing Materials and Processes
- Additive Manufacturing and 3D Printing Technologies
- Shape Memory Alloy Transformations
- Welding Techniques and Residual Stresses
- Fatigue and fracture mechanics
- Hydrogen embrittlement and corrosion behaviors in metals
- Material Properties and Failure Mechanisms
- Microstructure and Mechanical Properties of Steels
- High Entropy Alloys Studies
- Metal Alloys Wear and Properties
- Creativity in Education and Neuroscience
- Titanium Alloys Microstructure and Properties
- Non-Destructive Testing Techniques
- Structural Analysis of Composite Materials
- Advanced materials and composites
- Microstructure and mechanical properties
- Force Microscopy Techniques and Applications
- Epoxy Resin Curing Processes
- Elasticity and Wave Propagation
- Advanced machining processes and optimization
- High Temperature Alloys and Creep
- Material Properties and Applications
- Aeroelasticity and Vibration Control
- Corrosion Behavior and Inhibition
- Polymer crystallization and properties
Delft University of Technology
2002-2024
This paper addresses the effect of post-process heat treatments on microstructure and fatigue crack growth behaviour functionally graded (FG) laser powder bed fusion (L-PBF) Inconel 718 (IN718) superalloy. Sets samples were additively manufactured (AM) altering process parameters, namely power, scanning speed, layer thickness, hatch distance, beam distribution function, resulting in distinctly different microstructures. Two categories underwent treatment (HT) hot isostatic pressing followed...
In energy absorption applications, architectured metallic materials generally suffer from unrecoverable deformation as a result of local yield damage or inelastic buckling.Nitinol (NiTi) offers recoverable and dissipation due to its unique superelasticity, which can change the way we design additively manufacture energy-absorbing materials.The interplay between microstructure, mesoscopic deformation, macroscopic thermomechanical response NiTi is still not studied in depth.In this work,...
In this paper, the effect of microstructural anisotropy on fatigue crack growth behaviour functionally graded Inconel 718 fabricated through laser powder bed fusion (L-PBF) is investigated. Different manufacturing parameters, including low and high powers, were used to produce a variety non-graded (NG) (G) specimens in two build directions, vertical horizontal. addition, group heat treated wrought samples was tested as reference. It observed that different parameters result various grain...
In this work, the hydrogen fatigue of pipeline steel X60, its girth welds and weld defects were investigated through in situ testing. A novel gaseous charging set-up was developed, which involves a sample geometry that mimics small-scale with high internal gas pressure. The effect by measuring crack initiation growth, using direct current potential drop (DCPD) set-up, probes outer surface specimen. base metal specimens both experienced reduction life presence hydrogen. For metal, manifested...
Superelastic metallic materials possessing large recoverable strains are widely used in automotive, aerospace and energy conversion industries. working at high temperatures with a wide temperature range increasingly required for demanding applications. Until recently, high-temperature superelasticity has only been achievable multicomponent alloys fabricated by complex processes. In this study, novel framework of multi-scale models enabling texture microstructure design is proposed...
Additive manufacturing of NiTi shape memory alloys has attracted attention in recent years, due to design flexibility and feasibility achieve four-dimensional (4D) function response. To obtain customized 4D functional responses structures, tailorable phase transformation temperatures stress windows as well one-way or two-way properties are required. this goal, various heat treatments, including direct aging, annealing followed by were optimized for the Ti-rich (Ni49.6Ti (at.%)) fabricated...
This work discusses the design and demonstration of an in-situ test setup for testing pipeline steels in a high pressure gaseous hydrogen (H2) environment. A miniature hollow pipe-like tensile specimen was designed that acts as gas containment volume during test. Specific areas can be forced to fracture by selective notching, performed on weldment. The H2 used minimised so safely without need specialised equipment. is shown capable characterising Hydrogen Embrittlement (HE) through X60 steel...
This study investigated the in-situ gaseous (under 150 bar) hydrogen embrittlement behaviour of additively manufactured (AM) Inconel 718 produced from sustainable feedstock. Here, feedstock refers to powder by vacuum induction melting inert gas atomisation failed printed parts or waste CNC machining. All samples, namely AM-as-processed, AM-heat-treated and conventional samples showed severe embrittlement. Additionally, it was found that despite its higher yield strength (1462 ± 8 MPa)...
The simultaneous improvement of strength and toughness with grain refinement is widely known. However, the literature lacks studies on effect cleavage fracture in multiphase steels containing detrimental brittle inclusions. Understanding whether can effectively improve such will allow for their design. Therefore, a quenched tempered S690QL high steel Nb-rich oxide inclusions was subjected to rapid cyclic heating (RCH) treatment aimed at refinement, followed by quenching tempering produce...
Abstract In cylinder heads of compacted graphite iron (CGI), the heating and cooling cycles can lead to localized cracking due thermomechanical fatigue (TMF). Traditionally, TMF behavior is studied by thermal cycling smooth specimens. The resulting number failure ( N f ) constitutes a single parameter that be used predict actual service failures. Nevertheless, there are also some drawbacks conventional testing procedures, most noticeably prolonged times considerable scatter in test results....
Additively manufactured Nitinol (NiTi) architectured materials, designed with unit cell architectures, hold promise for customisable applications. However, the common assumption of homogeneity in modeling and additive manufacturing these materials needs further investigation because geometric-dependent melt pool behaviour results inhomogeneous microstructure thermomechanical properties. This study shows that property inhomogeneity at mesoscale is one reason pseudo-linear response partial...
Orientation contrast microscopy (i.e., electron backscattered diffraction, EBSD) was employed to monitor the plastic strain in loaded tensile samples of aluminium alloy Al6061 T4 condition. The kernel average misorientation (KAM) is known be an appropriate parameter orientation which has potential characterise by monitoring local misorientations. This technique applied here gauge extent zone around a fatigue crack. To establish magnitude (which can identified KAM parameter), series were...
In previous work on the thermo-mechanical fatigue (TMF) of compacted graphite iron (CGI), lifetimes measured under total constraint were confirmed analytically by numerical integration Paris’ crack-growth law. current work, results for CGI are further validated spheroidal cast (SGI), while TMF tests at different levels additionally performed. The Paris law is found to require a C P r i s parameter value per distinct level, indicating that does not capture all physical backgrounds crack...
Sub-size specimen testing offers a potentially elegant solution to accompany fatigue life assessments in determining vital parameters such as effective crack growth propagation thresholds (ΔKth,eff). Additively manufactured parts stand benefit from this potential build-by-build validation without foregoing process-inherent material saving and low lead times. In study, sub-size Laser Powder Bed Fusion (LPBF) produced Ti-6Al-4V SENB specimens built two orientations with stress relieved...