Effect of HVAF thermal sprayed NiCrMoW coating thickness on HIC resistance of carbon steels in sour environment

The exposure of certain carbon steels to sour environments can result in severe hydrogen induced cracking (HIC) damage in the oil and gas industry. Current mitigation techniques in this field have low reliability or are not able to provide long-term protection against such damage. Recent advancements in thermal spray technology have resulted in...

Thermal analysis of the Wire and Arc Additive Manufacturing process using the F.E. method

In this research, a thermal analysis of the wire and arc additive manufacturing process is presented based on the F.E. method. <br/><br/>An important quality of the F.E. model that is presented in this research is to describe the temperature field that is experienced by the deposited material in the wire and arc additive manufacturing process....

Initial characterisation of mechanical and corrosion properties of stationary shoulder friction stir welded bare and Alclad AA2024-T3 butt joints

Aluminium alloy AA2024-T3 is a lightweight and damage tolerant material, and is therefore often used in aerospace applications. However, this alloy is difficult to weld using conventional fusion welding techniques due to defects caused by the meld pool.<br/> <br/>Friction stir welding (FSW) was developed by The Welding Institute (TWI) in 1991 in...

Surface investigations of steels treated under hydrogen salt cavern boundary conditions

Large-scale hydrogen storage is a crucial part of the energy transition. The usage of salt caverns has a great potential in this process, but there are open questions regarding the construction’s lifetime which need to be investigated prior to their implementation. In this work, potential construction steels were studied. The conditions in a...

Study of Hydrogen Sorption/Desorption Effect on Iron-Based Materials: Influence of Microstructure on the Hydrogen/Metal Interaction

Studies on the impact of Hydrogen on the electrochemical and mechanical behaviour of Iron-based materials have been increasingly conducted in the past few years. This is mainly due to the ever-growing demand for sustainable energy sources, which involve Hydrogen and to meet the high structural and economic demands from the automobile sector and...

Optimizations of high-efficiency silicon heterojunction solar cells for tandem applications

Silicon heterojunction (SHJ) solar cells have exhibited efficiencies well above 25%. To further boost the efficiencies of c-Si-based solar cells, high-bandgap perovskite cells are stacked on top achieving a record efficiency of 29.52%. However, as most of the high-quality perovskite films are solution-processed, the front surface of the bottom...

Laser-beam welding as a method to characterise in-situ local thermo-mechanical conditions leading to liquid zinc embrittlement of Dual-Phase steel

Liquid metal embrittlement (LME) is a problem encountered in the resistance spot welding joining process of advanced high-strength steels in the automotive industry. Its occurrence reduces the mechanical performance of welds. The nature of resistance spot welding prevents in-situ characterisation of thermo-mechanical conditions causing LME....

The effect of localised laser treatment on the deformation behaviour of a Fe-Ni-C steel

The strength-ductility trade-off has been a long standing dilemma in material science. With the use of laser surface treatments, effort has been made in order to obtain a heterogeneous material with a well defined architectured microstructure to optimize this trade-off. In the present study, it is investigated how the deformation behaviour of...

Glass production from desert sand: Proof of concept and characterisation

For in-­situ resource utilisation start-up Maana Electric, an investigation was undertaken to determine whether a cover glass for solar panels can be produced using only desert sand as the raw material. During this investigation, the composition of desert sand, melt formation, processing temperatures, and mechanical and optical properties were...

Cleavage fracture during multiaxial loading: identifying stress parameters in ferritic steels

Brittle fracture in ferritic steels is a field in which a lot of research has been performed over the years. Most of this research has been done on uniaxially loaded specimens, such as single edge notched bend specimens. From these experiments, the maximum principal stress criterion is used in the Weibull distribution method as proposed by...

Response of 3D printed lattice-based spinal fusion cages to static and dynamic loading

Back pain is a major economic problem that can dramatically affect the quality of life. There are many causes that can lead to back pain, but intervertebral disc (IVD) degeneration is a recognised cause. The harmful effect of whole-body vibration (WBV) environment on the human intervertebral disc has been demonstrated to have an increased...

Gear Repair using Laser Metal Deposition

The urge for more sustainable and cost-efficient repair methods for damaged parts is growing every day. On the other hand, laser metal deposition (LMD) is gaining momentum. This flexible technique, where material is added in a layer-by-layer fashion with a minimal heat input offers solutions for a wide range of production and repair purposes....

Friction Forces of Micropatterned Elastomers with Carbon Fibre Fabric Reinforcement on Soft Substrates

Gecko-inspired adhesives mimic the external structure of geckos with micropatterned surfaces and the internal structure by fabric reinforcement in soft elastomer adhesive pads. Previous research measured the friction forces of synthetic adhesives, with either an external or internal structure, mainly on hard substrates. Much less is known about...

Bioengineered Skin in Psoriasis Modeling: Investigation of Automated Injection Molding of Dermo-Epidermal Models as compared with Benchmark Manual Fabrication.  

Bioengineered skin was initially developed for clinical application in reconstructive surgery, but nowadays it is also considered as a suitable skin model for research. Research applications range from assessment of cosmetic and pharmaceutical products to the modeling of pathological skin conditions. For example, psoriasis is a complicated skin...

A Customized Novel Halo with Displacement Based Pin Tightening for Pre-Operative Gravity Traction to Treat Severe Scoliosis

Severe scoliosis is a deformity of the curvature of the spine, mostly occurring in children. It is currently treated by performing Halo Gravity Traction (HGT) to reduce the curvature prior to surgery. In this procedure, a Bremer halo ring is fitted around the child's head and connected to the skull with a numberof pins. During the 3-month...

Investigating the size effect in SENB specimens with a triaxiality and Lode angle based damage model

This master thesis is built up around two questions. First: Is it possible to calibrate a ductile failure model, where the strain at failure is a function of stress triaxiality and Lode angle, using only a single SENB specimen? The failure model that is referred to describes local failure in a finite element model to simulate ductile fracture....

Structural assessment of the historical wrought iron tie rods used in the Duomo di Milano

The tie rods in the Duomo are structural elements, subject to monotonic loading and cyclic loading. Non-destructive testing is used to find cracks and determine their geometry. Lamb waves are applied to determine the presence of cracks in the tie rod and to estimate their positions. The cracks are located using eddy current testing. Finally the...