Fabrication of Multiple and Tapered Nozzle Holes for Diesel Engines by High-Speed Centrifugal Compaction Combined with Three-Dimensional Printed Cores, Part 1 - Development of Process

Diesel nozzle tips with tapered spray holes (inwardly larger) were produced using newly developed powder metallurgy (P/M) processing. Spray holes were formed by resin cores made by a three-dimensional printer. A 2.6 mu m steel powder (SCM415) was prepared as a slurry, and was compacted using a high-speed centrifugal compaction process into the resin mold with the core. The mold, core, and binder in the green compacts were eliminated by thermal decomposition, and the compacts were sintered by successive heating. Nozzle tips with three tapered holes were made in the sintered products without cracking or breakage. Although some problems exist in the remaining pores, large outlet holes (about 200 mu m) and a carbon residue, the holes can be used for spray examination.