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Ramzy Abou-Zeid

University of Manchester

X-ray Computer Tomography and Microstructural Characterisation of Additive Structures for Advanced Repair of Aeroengine Components

Nickel superalloys are used in the construction of aeroengine compressor blades for their high temperature mechanical performance, as well as their resistance to corrosion and oxidation. Maximising the service life of these components is essential to lower costs and reduce waste. Laser Blown Powder Directed Energy Deposition (LBP-DED) is an additive manufacturing method that is being explored for the repair of these components. Due to their extreme operating conditions, any repair process must minimally affect the microstructure of the components to preserve the desired mechanical properties, as well as ensure any repair structures exhibit commensurate properties to the existing substrate.

Kate Bowers

University of Sheffield

Understanding the effects of Die Geometry and Wheel Speed on Grain Size of Commercially Pure CONFORM Copper Wire

Olivia Broadbent-Clark

University of Manchester

Improving the Tolerance of Aluminium Alloys to Impurity Elements

The properties of aluminium alloys are greatly influenced by their composition and subsequent heat treatment. In this study the phases present during solidification and changes that occur during homogenisation are investigated in AA3104 and two recycled variants. Microstructural characterisation was performed using optical and scanning electron microscopy along with differential scanning calorimetry, with results compared to JMatPro simulations. The as-cast microstructure contained Al6(Mn,Fe), α-Al(Mn,Fe)Si, and Mg2Si phases with additions of T-AlCuMg in some alloys. During homogenisation, Mg2Si dissolved and the Al6(Mn,Fe) phase transformed into the α-Al(Mn,Fe)Si phase. Increased magnesium content decreased the rate of Mg2Si dissolution and decreased the rate of Al6(Mn,Fe) to α-Al(Mn,Fe)Si transformation.

Sydney Coates

University of Manchester

Understanding Cold Work Needed for Recrystallization of 316 LPBF Material and its Effect on the Material's Performance in PWR Primary Water

Co-authors: Fabio Scenini (University of Manchester), Ed Pickering (University of Manchester), Timothy Watkins (Rolls Royce), Karen Perkins (Rolls Royce)

As additive manufacturing becomes a more utilized manufacturing process, switching to laser powder bed fusion to create 316 stainless steel structural components for nuclear reactors is considered. However, current post-build HIPPing treatments aren’t able to erase the as-built laser scanning tracks, resulting in an inhomogeneous microstructure that increases the material’s susceptibility to stress corrosion cracking initiation. Because of this, induced cold work with a follow-up solution annealing heat treatment are used to produce an evolution of recrystallized microstructures. These microstructures have currently been analysed and will have SCC initiation tests done to compare their performance to the as-received material.

Tom Cole

University of Sheffield

An Investigation into the Local Structure of Ni-33.at%Cr via Neutron Diffraction Methods

Short-range order (SRO), defined by non-statistical relations between atomic neighbouring, is known to influence multiple intrinsic material properties. Historically identification of SRO has been limited to changes in these properties, but without sufficient understanding SRO effects on material mechanisms their separation from microstructural affects is only implied. Recently, advances in Total Scattering Techniques have presented the opportunity for far more in-depth characterisation of local structure relationships in alloys. The present work looks to assess the local structure of Ni-Cr alloy via neutron diffraction, such to further our understanding of the ordering in systems forming the basis of Ni-superalloys and MPEAs.

Lucas Cook

University of Sheffield

Analysis of the Relationship Between Wheel Speed and Grain Size of Aluminium Wire Produced Via the ConformTM Process

Co-authors: William J Pullfrey (University of Sheffield), Eric B Goodall (University of Sheffield), Martin Jackson (University of Sheffield)

The CONFORM process is a viable avenue for the production of low cost titanium from secondary sources. With research into the use of swarf as a viable feedstock showing that the CONFORM process can accommodate this change and produce viable fully consolidated wire from swarf. The possibility of the use of secondary sources of super-alloy material for the production of tooling allows a major step change to the economics of the process. This research aims to investigate the use of secondary materials on both the tooling and feedstock and compare the production of three different feed choices.

Grace Fidler

University of Manchester

Retained Austenite Decomposition in Low Alloy Steels

Low-alloy steels are used in a variety of applications as structural materials. They are often heat-treated to form microstructures comprising hard. Typical heat treatment usually comprise austenitisation, quenching and tempering steps. Following quenching, it is often found that small amounts of austenite remain untransformed at room temperature, called retained austenite. While the amount of this is small, it may influence the final microstructure and properties of the final component after tempering. The work uses XRD with Rietveld refinement and EBSD to measure the amount of retained austenite in the sample. Additionally, quench dilatometry is used observe austenite decomposition in situ.

Dillon Frith

University of Sheffield

The Replication of Defects in Titanium Aerospace Components Using Field-Assisted Sintering Technology (FAST) and the Analysis Method Force Response Mapping (FRM)

This presentation explores the application of Field-Assisted Sintering Technology (FAST) to replicate defects in titanium alloys, enabling a controlled approach to studying defect formation and behaviour. Analysis was conducted by means of Force Response Mapping (FRM) and Ultrasonic Testing (UT) to assess the fidelity of defect replication. This work provides insights into FAST and how the method can be used to create desired features within a material through the use of metallic powder.

Thomas Gillick

Dublin City University

Residual Stresses in Nickel Titanium Cantilever Beams Manufactured by Laser Powder Bed Fusion

Co-authors: Sampreet Rangaswamy, Medad C.C. Monu, Dermot Brabazon - Dublin City University

Residual stress is a detrimental effect that stems from the Laser Powder Bed Fusion (LPBF) additive manufacturing process. It develops due to the complex heating/cooling conditions that occur during the printing process, and causes cracking, delamination, distortion, and generally diminished mechanical strength in printed parts. The objective of this project is to evaluate residual stress in cantilever beams fabricated from Nickel Titanium (NiTi), that have been printed by LPBF using a variety of printing parameters. Residual stresses are evaluated by measuring beam deflections and inputting these values into the corresponding beam mechanics equations to determine a stress value, based on the beam deflection. This project aims to provide a simplified method of recording residual stress compared to other commonly used methods.

Meris Ikiz

Dublin City University

Investigation of the bond strength of laser-textured interference-fit joints

Ian Kiernan

Dublin City University

Measurement of Sliotar Coefficient of Restitution at High Speed

Jack Krohn

University of Sheffield

An investigation into the effect of FAST cooling rates on the lamellar microstructure in Titanium Aluminide GE4822

Field Assisted Sintering Technology (FAST) is a promising solid-state processing method for sintering challenging materials like titanium aluminides. FAST enables precise microstructural control, yet inconsistencies in phase diagrams and microstructure development highlight the need for a clear preprocessing strategy. This study examines the impact of cooling rates after dwell at various temperatures on lamellae formation in the titanium aluminide alloy GE4822. Results show that a dwell temperature of 1350°C is necessary for significant lamellar volume, with the microstructure being highly sensitive to cooling rate. At temperatures above 1375°C, a high lamellar fraction is consistently achieved, independent of cooling rate.

Eamonn Lawlor

University of Manchester

Ti-6Al-4V Cold Dwell Fatigue Loading - Effect of stress concentrations and fatigue crack growth rates

Jozef McGowan

University of Sheffield

Analysis of Tool Wear in Tungsten Carbide During Titanium Milling Across Different Processing Routes

Co-authors: Alex Graves (Sandvik-Coromant), Jack Krohn (University of Sheffield), Martin Jackson (University of Sheffield)

Titanium alloys are vital in aerospace due to their strength-to-weight ratio and oxidation resistance, but are challenging to machine. WC-Co tools wear rapidly during titanium turning, primarily due to cobalt and carbon diffusion. However, wear mechanisms in milling are less understood. This study investigates early-stage tool wear during shoulder milling of Ti-6Al-4V using inserts with varying cobalt content. After ~8 minutes of milling, inserts were sectioned and analysed via SEM. Adhered titanium was observed on flank faces, and potential subsurface porosity was examined, offering insight into early wear mechanisms and their impact on tool degradation during milling.

Xavier Ojeda

University of Manchester

Strain rate and temperature effects in slip activity in Titanium IMI834

Co-authors: João Quinta da Fonseca (University of Manchester), Philipp Withers (University of Manchester), Kate Fox (Rolls-Royce plc), Nigel Martin (Rolls-Royce plc)

Cold dwell is a time-dependent degradation process that can lead to the reduction of fatigue life of aero-engines. Cold dwell fatigue occurs in titanium alloys under cyclic loadings with dwell periods at peak stress below the yield strength. There are no measurements at the microscale that can demonstrate how this mechanism operates in an actual microstructure. Here, digital image correlation was used to investigate the material response to loading cycles at the micro-scale. Representative samples extracted from an actual forging were loaded to 80% and 90% of its yield strength, followed by a dwell period to induce creep at room temperature.

Yvonne Omowunmi-Kayode

Dublin City University

Laser Texturing of Ti-6Al-4V for Enhanced Anti-Biofouling and Hydrophobicity

This research investigates laser texturing as a method to alter the surface properties of Ti-6Al-4V with a focus on the wetting behaviour and fouling properties. Using laser ablation, micro-scale textures were fabricated on the surface, resulting in changes in surface roughness and wettability. The treated surfaces exhibited a transition from hydrophilic to hydrophobic highlighting the role of surface topography and chemistry in surface engineering. Results show that laser-based techniques can provide a precise, non-contact, environmentally-friendly surface modification method for introducing desired properties which are applicable in industries such as the medical industry which requires surfaces with anti-wetting and anti-biofouling functionalities.

Mostafa Salem

University of Sheffield

Simulating defect formation during the 3D printing of Nickel-based superalloys

Co-authors: Miguel Espadero (University of Sheffield), Hugh Banes (University of Sheffield), Prashant Jadhev (University of Sheffield), Hector Basoalto (University of Sheffield), Yu Lu (University of Birmingham)

This study investigates the microcracking mechanisms in nickel-based superalloys with a high γ′ (gamma prime) content. Using a multi-component Phase Field (PF) model, the formation of nanopores during the Laser Powder Bed Fusion (LPBF) process was simulated. A decoupled Phase Field - Crystal Plasticity (PF-CP) approach was subsequently applied to predict the development of micro-residual stresses. The results revealed a strong positive correlation between the degree of nanoporosity in CM247LC and macroporosity in the final fabricated components.

Ajai Sankar

University College Dublin

Microstructural Evolution and Performance of LPBF Ti-6Al-4V Shell/Core-Lattice structures upon Hot Isostatic Pressing (HIP)

Co-authors: Fan Wu (University of Manchester), Haole Qin (University of Manchester), Ramesh Raghavendra (South East Technological University), Ahmad Farhadi (Croom Precision Medical), Shane Keaveney (Croom Precision Medical), Wajira Mirihanage (University of Manchester), Denis Dowling (University College Dublin), Mert Celikin (University College Dublin) 

Additive manufacturing, particularly Laser Powder Bed Fusion (LPBF), has emerged as a revolutionary technique for fabricating complex structures. This study explores the effect of shell-core structures containing varying levels of retained powder (5–90%) on the densification, porosity, and microstructural evolution of Ti-6Al-4V alloys fabricated via LPBF and subjected to Hot Isostatic Pressing (HIP). The impact of internal lattice configurations and powder content on porosity control, microstructure optimization, and mechanical properties, particularly fatigue resistance, is investigated. The research finds that the volume density of lattice structures, combined with retained powder, influences grain coarsening, resulting in optimized microstructures with reduced porosity. These findings contribute to understanding the trade-offs between material properties, print productivity, and post-processing efficiency, offering new insights for enhancing the performance and scalability of LPBF-based manufacturing of high-performance titanium alloys.

Riccardo Sorrill

University College Dublin

The impact of shape factors on the AM print morphology using in-process monitoring

Richard Thompson

University of Sheffield

Review of computational methods of analysing rail wear

Andrea Villano

University College Dublin

Use of in-process monitoring to evaluate porosity generated during the Laser Powder Bed Fusion printing of Ti-6Al-4Vspinal cage devices

Co-authors: Fatemeh Golpayegani (University College Dublin), Denis P. Dowling (University College Dublin)

Porosity generation at edges is a major issue in additive manufacturing. This study investigates sawtooth geometry influence on keyhole porosity generation for L-PBF printed Ti-6Al-4V spinal cages. Such porosity is believed to be linked to localised overheating due to the alloy powder lower thermal conductivity compared to that of the bulk alloy. Differences in microstructure between cage edges and bulk alloy supported those findings. An attempt to corelate porosity with changes in photodiode data involved the implementation of an in-process monitoring system, unfortunately no direct corelation was found. By implementing different sawtooth geometries, a shift in pore position was observed when altering the sawtooth dimensions.

Matt Williamson

University of Manchester

The Influence of Creep on the Initiation of Environmentally Assisted Cracking

Co-authors: Timothy L. Burnett (University of Manchester), Philip B. Prangnell (University of Manchester), Matthew E. Curd (University of Manchester), Juhi Srivastava (University of Manchester), Zak Barrett (Airbus), Nick Byers (Airbus)

7xxx series aluminium alloys are used across a wide range of transport applications due to their high strength and low density; however, these alloys are susceptible to Hydrogen embrittlement-related Environmentally Induced Cracking (H-EIC) when exposed to warm humid air. Studies into EIC have mostly focused on the propagation of cracks. However, studies on a variety of metallic alloys have highlighted the impact of prior low temperature creep exhaustion on the crack initiation process. This presentation will explore our current understanding of the effect of creep on EIC, and on-going work investigating this relationship in 7xxx series aluminium alloys.

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