Cells are the building blocks of cell tissue, which in turn, merge to eventually make up whole human or animal organs. The same process applies to the materials that make up steel – just as cells eventually result in a living organism, micron-sized (1 micron = 1 millionth of a meter) microscopic structures adjoin to build steel materials. In the same way that the characteristics of cell tissue determines the ultimate nature and expression of an organism, the characteristics of microstructures determine those within steel materials. Though we understand this principle, the precise process in which the characteristics of microstructures determine the ones actually expressed within steel materials is still beyond our comprehension.

The Alloy Design Lab (ADL) headed by Professor Yoon-Uk Heo at the Graduate Institute of Ferrous & Energy Materials Technology, POSTECH, identifies the links among the microstructure of steel materials and their mechanical properties. Leveraging transmission electron microscopy, a cutting edge device to magnify the inner structure of the target sample by hundreds of thousands of times through the transmission of high voltage electron beams for observations, researchers at the Lab are able to thoroughly examine deep inside steel materials. Their ultimate goal is to provide solutions applicable to alloy designs and heat treatment process controls.

“With the technological advancement of electron microscopy, we are now able to observe steel materials all the way to the atomic level and fully trace extremely tiny structures”, Professor Heo commented, adding “This is a truly revolutionary addition to our understanding of steel materials”. The ADL is producing noteworthy research outcomes each year. The Lab has regularly contributed research papers illustrating its analyses of steel materials to such renowned international academic journals as Materials Characterization and International Journal of Plasticity. Last year, it produced seven articles, and in the first half of this year alone, six were published.

The ADL’s expertise acquired in the field is growing in proportion to the number of papers it publishes. Professor Heo mentioned “We have the knowledge necessary to determine the cause of material defects through microstructural analysis on the atomic and micron scale”, adding “this will surely lay the groundwork for designing new alloys even from the microstructural design phase”.

Professor Heo points out that there is still a heap of secrets yet to be discovered when it comes to steel materials. In fact, we have yet to solve the pressing need to discover a construction steel material that is both strong enough to support the building firmly, and tough and durable enough to stand the test of time. Another mystery lies in the phenomenon of ‘brittle fractures’ which refer to the overall physical properties of the materials being governed by nanometer-scale precipitation and atomic-scale impurity segregation. Professor Heo emphasizes that the Lab’s mission is “to unravel the secret of steel materials so that we can offer solutions for alloy designs and heat treatment process controls.