航空機エンジン及び過給機向け精密鋳造品の製造技術開発

抄録

  Precision casting is one of the most important processes for the production of aero engine and turbo-charger parts. The IHI Group has been developing and improving the manufacturing process for the last three decades according to demands for higher mechanical properties, higher quality, and lower production costs of casting parts. However, in recent years, new and higher-level demands for casting parts are seen accompanying the need to reduce environmental load, save energy, and reduce weight. In this article, three process development topics in IHI Group are introduced. With respect to the turbo-charger, new processes for achieving defect-free and low cost production processes for aluminum compressor impellers produced with plaster mold castings are needed. We therefore developed the Low-pressure and Vacuum casting process for the mass production of compressor impellers. Furthermore, as for aero engine parts produced with ceramics mold castings, we developed new low-cost alloys for the single crystal casting blade, and a new mold system for titanium alloy castings. The new alloy for single crystal castings showed equivalent creep properties to commercial alloys with lower rare earth elements contents. Material cost is significantly decreased, and it is expected to be applicable to new blade materials. The new molding system for titanium alloys castings prevent alpha case formation during solidification. This reduces post-processing costs and keeps mechanical properties higher.

  In these developments, IHI Group has contributed to the recent technology progress of precision castings, and we will make further contributions to the advancement of the casting industry in Japan.