New insights into hydrogen trapping and embrittlement in high strength aluminum alloys

An attractive approach to mitigate hydrogen embrittlement (HE) is to use nano-sized particles to immobilize hydrogen. However, the atomic scale relationship between different particle-matrix characteristics in aluminum alloys and the susceptibility to HE is unknown. In this study, the effects of interactions between various interfaces and...

On the use of transfer modeling to design new steels with excellent rotating bending fatigue resistance even in the case of very small calibration datasets

In this research a machine learning model for predicting the rotating bending fatigue strength and the high-throughput design of fatigue resistant steels is proposed. In this transfer prediction framework, machine learning models are first trained to estimate tensile properties (yield strength, tensile strength and elongation) on the basis of...

Fundamentals and application of solid-state phase transformations for advanced high strength steels containing metastable retained austenite

Over many decades, significant efforts have been made to improve the strength-elongation product of advanced high strength steels (AHSSs) by creating tailored multi-phase microstructures. Successive solid-state phase transformations for steels with a well selected chemical composition turned out to be the key instrument in the realisation of...

A first step towards computational design of W-containing self-healing ferritic creep resistant steels

In this work, we combine a generic alloy-by-design model with a novel concept, the nucleation barrier for the formation of Laves phase to fill the creep cavities, in order to develop multi-component creep resistant steels with kinetically tuned self-healing behaviour. In the model the high-temperature long-term strength is estimated by...

Physical metallurgy-guided machine learning and artificial intelligent design of ultrahigh-strength stainless steel

With the development of the materials genome philosophy and data mining methodologies, machine learning (ML) has been widely applied for discovering new materials in various systems including high-end steels with improved performance. Although recently, some attempts have been made to incorporate physical features in the ML process, its...

The Effect of Microstructure on the Abrasion Resistance of Low Alloyed Steels

The thesis attempts to develop advanced high abrasion resistant steels with low hardness in combination with good toughness, processability and low alloying additions. For this purpose, a novel multi-pass dual-indenter (MPDI) scratch test approach has been developed to approach the real continuous abrasion process and unravel abrasion damage...

Alloy by design: A materials genome approach to advanced high strength stainless steels for low and high temperature applications

We report a computational 'alloy by design' approach which can significantly accelerate the design process and substantially reduce the development costs. This approach allows simultaneously optimization of alloy composition and heat treatment parameters based on the integration of thermodynamic, thermo-kinetics and a genetic algorithm...

Computational design of heat resistant steels with evolving and time-independent strengthening factors

Alloy design by the traditional trial and error approach is known to be a time consuming and a highly cost procedure, especially for the design of heat resistant steel where the feedback time is intrinsically long. The significant developments in computational simulation techniques in the last decades have made a theory-guided computational...

Optimization of microstructure and properties of high strength spring steel

This thesis describes a research project on the development of a new grade of low cost spring steel with exceptional mechanical properties on the basis of a complete understanding and quantification of the metallurgical processes taking place during the various stages of the heat treatment. The new composition in combination with a new 2-step...

Tailoring the Mechanical Properties of Titanium Alloys via Plasticity Induced Transformations

Titanium alloys possess good corrosion properties, high temperature stability and high strength-to-weight ratio. However, they fall short in providing the optimum strength-ductility relation in the most demanding structural applications, including the aerospace sector. Inspired by the possibility of enhancing the strength-ductility relation in...

Tailoring the mechanical properties of titanium alloys via plasticity induced transformations

Titanium alloys possess good corrosion properties, high temperature stability and high strength-to-weight ratio. However, they fall short in providing the optimum strength-ductility relation in the most demanding structural applications, including the aerospace sector. Inspired by the possibility of enhancing the strength-ductility relation in...

Genetic Design of Ultra High Strength Stainless Steels: Modelling and Experiments