PhD Studentship: Reversing Hydrogen Embrittlement Sustainably: Finding a Pathway to Facilitate Long-term Hydrogen Storage and Distribution

The goal of this project is to invent a rapid, sustainable technique for healing hydrogen-induced embrittlement in metals and alloys using high-frequency, low-density electric currents. 

Background:

Hydrogen is poised to be the green fuel of the future. For a practical hydrogen-based economy, efficient and effective storage and distribution are crucial. 

However, it is well known that equipment exposed to hydrogen induces permeation through metals/alloys that lead to eventual degradation of mechanical properties, especially the plasticity of materials. This phenomenon is known as hydrogen embrittlement (HE). This failure always occurs at low stress levels with brittle fracture, which can cause catastrophic failure leading to huge economic losses. 

Current Prevention Techniques for HE are based on two approaches:

• Use of surface treatments that involve the application of surface coatings.
• Modification of the material microstructure.

The main drawback of the first approach is that coatings may peel off (due to expansion/contraction) or degrade over time. Hydrogen being a very small molecule can easily percolate through a minuscule defect in the coating into the main metal matrix beginning the process of HE. The second approach requires significant expertise and processing costs upfront to implement. Incorporating such techniques is known to reduce HE but does not eliminate it.

A recent discovery:

Some preliminary studies recently performed in our research group show the potential for reversing HE rapidly without the need for thermal treatments. Our experiments show that hydrogen-charged steel samples show a reduction in ductility when treated with pulsed electric currents for a duration of just 30 min – full recovery of all ductility. 

We expect the healing to happen even quicker – probably in 10 min or less, which is yet to be explored and will be a thrust of the PhD study. For equivalent thermal treatment, this would take hours on end – inculcating significant energy costs making the thermal treatment/healing route completely impractical. 

Research plan and objectives of the PhD programme:

• Gain a fundamental understanding of the healing mechanisms using pulsed electric currents across length scales (thus we can address the underlying physics of the process from the smallest to the largest of length and time scales). We will link this to the microstructure of the metal/alloy used. We will perform computational multi-scale crystalline mechanics.
• Link the above to experimental studies to assess the optimal healing parameters (peak current, nominal current, frequency and duty cycle) to reverse embrittlement. Here we will balance the time needed for treatment with the energy cost of the healing process.
• Seek pathways for deployment of the technology in existing hydrogen storage/distribution infrastructure. Demonstrate the feasibility of this technique by carrying out a detailed energy cost/benefit of the system. Engage with industry partners to address current and future needs.
• Disseminate this knowledge via publications and conference presentations. Also, explore the potential for commercialising this technology.

Supervisors: Primary supervisor: Anish Roy

Entry requirements

Applicants should have or expect to achieve, at least a 2:1 (or equivalent) in any engineering degree programme or physics or any applied sciences.

To apply: All applications should be made online via the above ‘Apply’ button. Under programme name, select ‘Mechanical and Manufacturing Engineering/Electronic, Electrical & Systems Engineering’ and quote the advert reference number FP-AR-2025 in your application.

Funding Details

Funding Comment

This 3-year studentship provides a tax-free stipend of £19,237 per annum, plus tuition fees.

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