Researchers Develop USTTs to Measure Tungsten Coating on Ferritic Steel

Researchers Develop USTTs to Measure tungsten Coating on Ferritic Steel

Researchers at Tohoku University have successfully used ultra-small test techniques (USTTs) to measure tungsten coating on ferritic steel. The metallic coating protects structural materials from harsh environments. It is essential for, for example, gas turbines (whose components may reach high temperatures) or the first wall of a nuclear fusion reactor. However, the limited thickness and brittleness of the coating make it difficult to measure the interfacial bond strength of the coating material.

Ferritic steels and advanced ferritic steels have been expected to be used in fission and fusion reactors because of their excellent irradiation resistance. Focused ion beam (FIB) and nanoindentation techniques have enabled ultra-small test techniques that can evaluate mechanical properties in small areas. However, further research is needed to investigate the applicability of ultra-small test techniques in measuring heterogeneously bonded and coated materials.

A team of researchers has now employed USTTs to test the interfacial bond strength of a 0.2 mm tungsten foil coated on ferritic steel. The group, which included Professors Xiangyu Wu and Ryuta Kasada of Tohoku University, used microtensile tests and microshear compression tests. Their research was published in Materials Science and Engineering A.

The group applied 0.2 mm-thick tungsten foil to ferritic steel using an underwater explosive bonding method developed by one of its members, Kazuyuki Hokamoto of Kumamoto University. Based on this, the researchers prepared micron-scale compression specimens using FIB. These specimens were then examined by micro shear compression tests to obtain load-displacement curves. When the shear deformation was reduced to 1 μm2, the shear strength was higher than that of the tungsten coating.

"Our results show that the ultra-compact test technique successfully measures the true interfacial shear strength of brittle tungsten and steel joints," Kasada said." We hope the USTTs can be applied to measure the bond strength of various coating materials, contributing to the safe application of multi-material technologies used in industrial components."

• < Prev
• Next >

Link to this article：Researchers Develop USTTs to Measure Tungsten Coating on Ferritic Steel

Reprint Statement: If there are no special instructions, all articles on this site are original. Please indicate the source for reprinting:Tungusten，Thanks！^^