skip to primary navigationskip to content
 

Dr Robert Krakow

Robert Krakow

Photo of Robert Krakow

rk471@cam.ac.uk

+44 (0)1223 334597

 

My research interest is in linking mechanical properties of alloys to their microstructure which is the size, morphology and distribution of grains and other phases. More specifically, I aim to determine the complex crystallography and chemistry of superalloy phases at the nanoscale with the help of transmission electron microscopy. This helps to understand the thermodynamic stability of superalloys and whether their mechanical properties are likely to change over time, which is especially relevant for the safety and service cost of engineering applications like aero engines.

 

Data from Robert Krakow

 

I compared, for example, the complex response of a Ni-base alloy under slow strain rate tensile load with crack propagation conditions and found that both show anisotropic behaviour which is a consequence of the manufacturing conditions and an alignment of a secondary phase. Moreover, I used advanced microscopy techniques (like FIB/SEM 3D tomography) to show that this secondary phase leads to chemical segregation and to the formation of two previously unreported, deleterious phases due to solute atom rejection of the aligned phase.

From July 2016, I am going to continue my research, for example by trying to determine the complex crystallography at the nucleation site of the two new phases. I am also going to work with completely new alloy systems that are promising candidate alloys for high-temperature applications. 

 

 

A.S. Eggeman, R. Krakow, and P.A. Midgley, “Scanning precession electron tomography for three-dimensional nanoscale orientation imaging and crystallographic analysis,” Nat. Commun., vol. 6, p. 7267, 2015.

D. Rossouw, R. Krakow, Z. Saghi, C.S. M. Yeoh, P. Burdet, R.K. Leary, F. de la Peña, C. Ducati, C.M.F. Rae, and P.A. Midgley, “Blind source separation aided characterization of the γ’ strengthening phase in an advanced nickel-based superalloy by spectroscopic 4D electron microscopy,” Acta Mater., pp. 1–28, 2016.

D. Huenert, M. Proebstle, A. Casanova, R. Schluetter, R. Krakow, M. Buescher, P. Randelzhofer, K. Loehnert, T. Witulski, S. Neumeier, and C. M. F. Rae, “ATI718Plus® – new nickel based alloy and its capabilities (accepted),” Superalloys 2016 13th Int. Symp. Superalloys, vol. 1, no. 1, pp. 1–11, 2016

R. Krakow, D N Johnstone, F Wisniewski, D Rossouw, A S Eggeman, D Hünert, M C. Hardy, C.M.F. Rae and Paul A. Midgley , “On the chemistry and crystallography of topologically close-packed (TCP) phases in ATI 718Plus” Acta Mater., pp. 1–25, 2016. (submitted)