Development of hybrid material using plasma spraying and laser treatment for thermochemical water-splitting iodine-sulfur process

Ioka, Ikuo  ; Kuriki, Yoshiro*; Iwatsuki, Jin ; Kubo, Shinji  ; Inagaki, Yoshiyuki

IS process is composed of the Bunsen reaction, thermal decomposition of hydrogen iodide and thermal decomposition of sulfuric acid. By carrying out three reactions sequentially, water can be decomposed into hydrogen and oxygen. Evaluation of materials for the sulfuric acid decomposition has revealed that high silicon alloys have excellent corrosion resistance. The material is brittle, so it's difficult to use them independently as structural materials. So, we have developed a hybrid material with the corrosion-resistant and the ductility. In this work, the hybrid material was made by the plasma spraying and laser treatment. Corrosion tests on the hybrid material were carried out. The evaluation that paid attention to cracks of the surface layer was performed using OM and SEM/EDX. The surface of the hybrid material showed corrosion resistance in boiling 47% sulfuric acid though some cracks were observed in the surface layer from the cross section observation.