Secondment period: 14th November – 14th December 2022 within WP1 “Development and characterisation of advanced MH materials for hydrogen storage and compression”

Figure 1: Picture from left to right of Moegamat Wafeeq Davids (UWC), Roman Denys (HYSTORYS) and Thabang Ronny Somo (UWC) in laboratory at IFE by Arc-Melter used for preparation of metal hydride alloys.

Figure 2: Picture from left to right of Moegamat Wafeeq Davids (UWC), Prof V.A Yartys (IFE) and Thabang Ronny Somo (UWC) at entrance of IFE building.

Objective of Secondment:

Within WP1, the focus is placed on multi-component AB2-type intermetallic alloys (A=Ti,Zr; B=Mn,Cr,V,Fe,Ni,…) to be used for both hydrogen storage and compression.  Recently huge interest in High Entropy Alloys (HEA’s) have been the subject of many researchers due to the assumed high hydrogen H/M ratio.

The objective of this secondment was to prepare HEA’s consisting of several individual metals in equal or close to equal atomic fractions. HEA’s often exhibit outstanding application-related properties such as high strength and wear resistance, corrosion resistance and high-temperature stability. Some HEA’s are also characterised by attractive hydrogen sorption properties.

We have completed numerous simulation studies to determine the hydrogen capacity, entropy and enthalpy of these HEA’s using theoretical tools namely CALPHAD (Calculation of Phase Diagrams) and DFT (Density Functional Theory).  The next step of our work is to prepare these alloys via arc melting method at IFE based in Norway.

The list of alloys we prepared is shown below; all samples were prepared via arc-melting and annealed at 950 oC for 24 hrs.

  1. TiMn1.52
  2. TiMn2
  3. Ti0.5Zr0.5Mn2
  4. Ti0.5Zr0.5Mn1Fe1
  5. Ti0.5Zr0.5Mn0.66Fe0.66Cr0.66
  6. Ti0.5Zr0.5Mn0.5Fe0.5Cr0.5Ni0.5
  7. Ti0.9Zr0.1Mn0.5Fe0.5Cr0.5Ni0.5
  8. Ti0.8Zr0.2Mn0.5Fe0.5Cr0.5Ni0.5
  9. Ti0.75Zr0.25Mn0.5Fe0.5Cr0.5Ni0.5

 

The alloys prepared will be fully characterized at the University of the Western Cape (UWC). The results will be compared to our simulation results to see if there are any correlations which will later result in joint publication between IFE and UWC.

We also worked on an extensive review paper titled “Hydrogen Storage Behaviours of High Entropy Alloys”, which we plan to submit at the beginning of 2023.