Martin P. Harmer Research
Professor Harmer’s research group is involved with the kinetic engineering of interfaces (grain boundaries and surfaces) in ceramic and metal systems in order to tailor their atomic transport rates, microstructure and properties. It is focused on the new discovery that internal interfaces have complex three-dimensional structures called ‘complexions’. (ref) In some research programs, the aim is to speed up boundary transport, for example to grow single crystals from polycrystals or to shorten the time of a manufacturing process. In other research programs, the goal is to slow down interface movement, for example to promote oxidation and creep resistance of high temperature alloys or to suppress abnormal grain growth in order to make ultra high strength materials, or to inhibit the coarsening of nanosize grain structures. His research makes extensive use of Lehigh’s state-of-the-art electron microscopy facilities.
Atomic-resolution scanning transmission electron microscopy image of neodymium cations (bright spots) segregating to an alumina grain boundary.
(ref) Shen J. Dillon, Ming Tang, W. Craig Carter and Martin P. Harmer, “Complexion: A new concept for kinetic engineering in materials science”, Acta Materialia, 55(2007) 6208-6218.