A5028128064- Additive Manufacturing Materials and Processes
- Additive Manufacturing and 3D Printing Technologies
- Metallic Glasses and Amorphous Alloys
- High Entropy Alloys Studies
- Welding Techniques and Residual Stresses
- Advanced materials and composites
- Aluminum Alloy Microstructure Properties
- Titanium Alloys Microstructure and Properties
- Glass properties and applications
- High-Temperature Coating Behaviors
- Injection Molding Process and Properties
- Phase-change materials and chalcogenides
- Magnetic Properties and Applications
- Magnetic Properties of Alloys
- Nuclear Materials and Properties
- Aluminum Alloys Composites Properties
- Intermetallics and Advanced Alloy Properties
- Cellular and Composite Structures
- Manufacturing Process and Optimization
- Magnetic properties of thin films
- Quasicrystal Structures and Properties
- Metallurgy and Material Forming
- Fusion materials and technologies
- Electromagnetic wave absorption materials
- Microstructure and mechanical properties
University of Sheffield
2015-2024
Materials Science & Engineering
2015-2023
Sir Robert McAlpine (United Kingdom)
2020-2021
University of Manchester
2012-2016
Delft University of Technology
2005
McGill University
1980
The Selective Laser Melting (SLM) process generates large thermal gradients during rapid melting of metallic powdered feedstock. During solidification certain alloys suffer from thermally induced micro-cracking which cannot be eliminated by optimisation. An alloy's crack susceptibility may reduce increasing its Thermal Shock Resistance (TSR), potentially achieved through an increase in tensile strength. This hypothesis is investigated with Hastelloy X, a common nickel-base superalloy known...
Selective Electron Beam Melting (SEBM) is a promising powder bed Additive Manufacturing technique for near-net-shape manufacture of high-value titanium components. However without post-manufacture HIPing the fatigue life SEBM parts currently dominated by presence porosity. In this study, size, volume fraction, and spatial distribution pores in model samples have been characterised 3D, using X-ray Computed Tomography, correlated to process variables. The average fraction (< 0.2%) was measured...
Without post-manufacture HIPing the fatigue life of electron beam melting (EBM) additively manufactured parts is currently dominated by presence porosity, exhibiting large amounts scatter. Here we have shown that size and location these defects crucial in determining EBM Ti-6Al-4V samples. X-ray computed tomography has been used to characterise all pores samples prior testing follow initiation growth cracks. This shows stage comprises a fraction (>70%). In initiating defect was often some...
X-ray computed tomography has been used to track the behaviour of individual pores found in selective electron beam melted additive manufactured titanium. Porosity was shrink below detection limit microtomography (< 5 μm) upon hot isostatic pressing. Spherical argon containing gas pores, which have a high internal pressure following pressing, progressively reappear and grow proportion their original as-built size during temperature (β-anneal) treatments, whereas larger irregular low did not...
Abstract Ti-6Al-4V parts, produced by selective electron beam melting additive manufacturing, have been studied X-ray computed tomography (XCT) to track pore closure during a standard hot isostatic pressing (HIPing) cycle. Comparison of repeated XCT scans before and after HIPing, on worst-case samples with different geometries, confirmed that all internal porosity was shrunk below the resolution limit equipment used (~5 µm) following HIPing cycle, apart from defects surface connected ligaments.
Additive Layer Manufacturing (ALM) is becoming a more widely accepted method for the production of near net-shape products across range industries and alloys. Depending on end application, level process substantiation required new parts or Prior knowledge likely parameter ranges that will provide target region integrity can save valuable time resource during initial ALM trials. In this paper, parameters used powder bed have been taken from literature present study to construct normalised...
The additive manufacturing of metals requires optimisation to find the melting conditions that give desired material properties. A key aspect is minimising porosity forms during process. corresponding analysis pores different types (e.g. lack fusion or keyholes) therefore desirable. Knowing form under thermal allows greater insight into In this work, two pore classification methods were trialled: unsupervised machine learning and defined limits. These applied 3D data from X-ray computed...
Rapid melt pool formation and solidification during the metal powder bed process Selective Laser Melting (SLM) generates large thermal gradients that can in turn lead to increased residual stress within a component. Metal anchors or supports are required be built in-situ forcibly hold SLM structures place minimise geometric distortion/warpage as result of this stress. Anchors often costly, difficult time consuming remove limit freedom Additive Manufacturing (AM) process. A novel method known...
Electron Beam Melting (EBM) as a means of Additive Manufacturing (AM), is interest for the fabrication intricate geometries cellular materials in areas where complex architectures are needed, e.g. biomedical implants. Most studies have focused on specific and so effect structure mechanical performance not well understood. Many kinds micro- macro-scale defects can arise additively manufactured components, assessment their influence properties needed. In this work, lattices Ti-6Al-4V having...
Intelligent application of materials with site-specific properties will undoubtedly allow more efficient components and use resources. Despite such being ubiquitous in nature, human engineering structures typically rely upon monolithic alloys discrete properties. Additive manufacturing, where material is introduced bonded to sequentially, by its very nature a good match for the manufacture changes property built-in. Here, some recent progress additive manufacturing spatially varied reviewed...
The Electron Beam (EBM) additive manufacturing process is well suited to fabricating complex structural designs in Ti–6Al–4V because of the design freedoms it offers combined with strong and consistent material properties. However has been observed that complications may arise when truss-like structures (such as those produced via topology optimization) form undersized features on finished part. issue appears affect truss members are not aligned vertical build direction, an apparent lack...