H
Hiroyuki Kokawa
Researcher at Shanghai Jiao Tong University
Publications - 280
Citations - 11770
Hiroyuki Kokawa is an academic researcher from Shanghai Jiao Tong University. The author has contributed to research in topics: Welding & Friction stir welding. The author has an hindex of 51, co-authored 271 publications receiving 10329 citations. Previous affiliations of Hiroyuki Kokawa include Tohoku University & Toho University.
Papers
More filters
Journal ArticleDOI
Nitrogen desorption by high-nitrogen steel weld metal during CO2 laser welding
TL;DR: In this article, the nitrogen desorption by high-nitrogen steels (HNSs) containing 0.32 and 0.53 pct nitrogen during CO2 laser welding in an Ar-N2 gas mixture was investigated and the obtained data were compared with those for arc welding and at the equilibrium state predicted by Sieverts' Law.
Journal ArticleDOI
Analysis of plastic flow of the al alloy joint produced by friction stir spot welding
TL;DR: In this article, the development of the stir zone and plastic flow of the material during friction stir spot joining of aluminium alloys was examined through the observation of macro sections of the joints produced at various process times.
Journal ArticleDOI
Microstructure and properties of friction stir welded high strength Fe–36wt%Ni alloy
TL;DR: In this article, high strength Fe-36-wt%Ni alloy sheets with 3mm thickness were successfully friction stir welded and defect-free welds were acquired at travelling speed of 2mm/s and rotational speed between 600 and 1000rpm.
Journal ArticleDOI
Crystalline phases, microstructures and electrical properties of hafnium oxide films deposited by sol-gel method
Zhan Jie Wang,Toshihide Kumagai,Hiroyuki Kokawa,Jiunnjye Tsuaur,Masaaki Ichiki,Ryutaro Maeda +5 more
TL;DR: In this paper, HfO2 films were grown on SiO2/Si and Pt/Ti/SiO 2/Si substrates by a sol-gel method, and their crystalline structure, microstructure and electrical properties were investigated.
Journal ArticleDOI
Nitrogen absorption by iron and stainless steels during CO2 laser welding
TL;DR: In this article, the nitrogen absorption by iron, Fe-20Cr-10Ni alloy, and SUS329J1 duplex stainless steel during CO2 laser welding in an Ar-N2 gas mixture was investigated and compared with equilibrium data predicted on Sieverts' law and data on absorption during arc and YAG laser welding.