Toshiharu Morimoto

Synthetic Studies on Chartelline C: Stereoselective Construction of the Core Skeleton

What a core-ker! The title synthesis was achieved using a route featuring an intramolecular Mitsunobu reaction of a nosyl amide, stereoselective construction of the β-lactam, and formation of an enamide moiety by selenoxide elimination. The stereochemistry of the alkylation for the formation of the β-lactam was controlled by a secondary hydroxy group on the ten-membered ring. SEM=2-(trimethylsilyl)ethoxymethyl; TBS=tert-butyldimethylsilyl.

Application of Recrystallization Texture Evolution Model to Predict Plastic Formability in Steel Strips

T.M.C.P.(Thermo Mechanical Control Processing) has been widely used to improveplastic formability in steel strips. We have produced interstitial free steel(IF steel) strips and ferriticstainless-steel strips through T.M.C.P. rolling method. Optimizing conditions of hot rolling, hotrolled annealing, cold rolling and cold rolled annealing, we developed texture prediction model. Wecan predict rolling texture accurately using the conventional Taylor model. Moreover, we preciselypredict recrystallization texture classifying the total number of microscopic slips which arecalculated using the Taylor model. We consider that these calculated results provednucleation-oriented model and two types of recrystallization and grain growth mechanisms exit inour studies. One mechanism is that grains which had the small total number of microscopic slips arepreferred orientation for the hot rolled and annealed ferritic stainless-steel strip. The othermechanism is that grains which had the high total number of microscopic slips are preferredorientation for the cold rolled and annealed IF steel strip.

Warm Rolling Technique for Amorphous Alloy Strip Produced by Ultrarapid Cooling-Thermal Spraying Based on Hydraulic-Stress-Induced Structural Relaxation

Amorphous alloys have many superior properties such as high tensile strength,anticorrosion and easy soft-magnetism, but few amorphous alloys have been used as final productsbecause they lack plasticity at room temperature. Thus, we have developed a new amorphous alloyrolling method. Although the amorphous alloy was brittle at room temperature, it has deformedplastically by semisolid rolling under hydraulic stress. After being subjected to ultrarapidcooling-thermal spraying, amorphous alloy strips were rolled with a ditch roll in the viscoelasticregion below the glass transition temperature. Using this rolling method, we successfully preformedstrips for use in fuel cell separator. This rolling technique is based on the principle of stress-inducedstructural relaxation under hydraulic stress.