22/4/13: New paper: Effects of Irradiation Temperature and Dose Rate on the Mechanical Properties of Self-Ion Implanted Fe and Fe-Cr Alloys
This paper documents very strong dose rate effects on the hardening produced in FeCr alloys by ion-implantions. It appears that the strong hardening seen at low dose rates is due to chromium segregation to the dislocation loops produced by the radiation damage. For further details see here.
1/3/13: September workshops: "Tungsten" and "Modelling"
Our previous 2½-day workshops, on "Micromechanics", "ODS Alloys" and "Ion Irradiation" were well-received enough that we plan to run two workshops back-to-back this year, in the week 23-27 September. The meetings will be on:
- Tungsten for Nuclear Applications. 23-25 September. Registration is now open.
- Modelling of Radiation Damage in Materials. 25-27 September. Registration is now open.
05/1/13: Review Paper Published
A large review paper which we have contributed to has just been published in the Journal of Nuclear Materials. This paper summarises work carried out on tungsten for fusion applications across Europe under the EFDA-W project. James Gibson, David Armstrong and Steve Roberts contributed to the work on fracture at the macro and micro-scale of tungsten and tungsten-tantalum alloys. The full paper is online here.
18/12/12: New Paper
Xiaoou Yi has just had her paper on in-situ studies of radiation damage in tungsten and tungsten-rhenium published in Philosophical Magazine. The full paper is online here.
20/11/12: RaDIATE project
RaDIATE: Radiation Damage In Accelerator Target Environments - we have just started work on a new project jointly between Oxford Materials, STFC and Fermilab, to study effects of radiation damage (high energy protons) in targets for high-power neutron & neutrino "factories" .
See www-radiate.fnal.gov for more details.
19/10/12: New Papers
The MFFP group have had two new papers on the mechanics of ion implanted materials published in The Journal of Nuclear Materials. The first shows the differences in hardening under ion irradiation between pure tungsten and tungsten 5wt% rhenium. Atom probe tomography and TEM were used to look at the chemical segregation and defect populations produced under implantation from 0.04dpa to 33dpa. The full paper is available here. The second investigates the effect of ion damage on the changes in hardness of a range of binary iron-chromium alloys. In higher chromium alloys damage was seen to saturate by 2dpa whereas continued hardening was seen in the lower chromium. The full paper is available here.
19/09/12: PhD Open Day at Culham, 15 November 2012
We will be at this event - if you might be interested in doing a doctorate in fusion materials, come and talk to us!
19/09/12: Oxide-dispersion Strengthened Alloys for Nuclear Application: 24-26 September 2012.
A three-day workshop on oxide-dispersion strengthened alloys for nuclear applications . This low-cost meeting will be centred on about a dozen keynote lectures (of ~ 1 hour) and will give ample time for discussions centred around the lectures and two substantial poster sessions where "work in progress" will be reported. The final programme is now available. For more details see here.
This week our first neutron-irradiated material arrived in Oxford: a 2.3mm diameter, 200µm thick piece of Fe-5%Cr, irradiated at the Advanced Test Reactor at Idaho National Lab, courtesy of our collaborator Bob Odette at UCSB. Chris Hardie earlier spent a week at CAES, Idaho Falls, cutting many micromechanical test elements into it (see News 26/3/12). Now to test them!
25/7/12: New Paper on ion implantation and micromechanical testing
Ele Grieveson has just had her Part II (4th year undergraduate) project work published in the Journal Of Nuclear Materials. After self-ion implantation in pure iron, both micro-pillar compression and nanoindentation were used to examine the changes in mechanical properties. The implanted pillars have a deformation mode which differs markedly from the unimplanted pillars but show no change in yield-stress. This suggests that the controlling mechanism for deformation is different between nanoindentation and micropillar compression and that care is needed if using micropillar compression to extract bulk properties of irradiated materials. The full paper is here.
16/7/12: Nuclear Materials Short Course: 3-7 September 2012.
20/4/12: Tungsten Ion Implantation
James Gibson and Dave Armstrong have just returned from the first sucessful tungsten ion and helium ion implantation we have performed at CEA Saclay using the Jannus facility.
12/4/12: New Paper on Tungsten Foils
Xiaoou Yi and Dr David Armstrong have been collaborating with researchers from KIT, Germany, and Plansee, Austria, on characterising thin tungsten foils for use in W/W composites for structural applications in fusion reactor divertors. Their new paper which explains some of the interesting mechanical properties of such thin foils can be found here.
Chris spent some days at UCSB, discussing work with Bob Odette and group, before driving (!) to Idaho Falls to start work our first neutron-irradiated materials. He is at CAES, Idaho Falls, this week, making FIB-machined micro-cantilevers in Fe-6%Cr alloys irradiated at INL, and supplied to us by Bob Odette. Image shows Chris' first (and smallest planned!) cantilevers.
14/02/12: Dave Armstrong and Steve Roberts at UCSB
Dave and Steve were at a three-day meeting at the University of California, Santa Barbara, on "Challenges in Tungsten for Fusion Applications". See here for pictures.
17/01/12: ITER news
Collaborative work on oxide-dispersion strengthened steels, involving Sergio Lozano-Perez (Oxford), Vanessa de Castro (UC3M, Spain) and Emmanuelle Marquis (University of Michigan, USA) is featured in "ITER News".
After one of our Friday morning meetings, I got everyone (well, nearly everyone) together for a photo.
So we now also have a "Group Photos" page.