Application of Ceramics to Turbocharger Rotors for Passenger Cars

Abstract

Nissan has been developing and marketing ceramic turbocharger rotors for over five years. This paper outlines the major theories and techniques used in ceramic fabrication, joining of ceramic and metal components and machining of ceramics. It also presents a dynamic stress analysis using DYNA3D and describes techniques used in performing impact damage experiments, reliability evaluation and lifetime prediction NOMENCLATURE A pre-multiplier in crack velocity a crack length B constant D constant E Young's modulus F failure probability H hardness Kc fracture toughness KiCcritical stress intensity factor L load m Weibull modulus N crack velocity exponent P survival probability r radius S material strength t time V velocity ve effective volume Y shape factor p density 6 stress

Dense and near-net-shape fabrication of Si3N4 ceramics

“…Specifically, several key variables on the properties of injection molded parts have been studied such as particle size distribution of the starting powder, binder composition, powder solid loading, and compounding shear level [1,39,[82][83][84].…”

“…Considering that one of the must difficult components to form by conventional ceramic forming processing has been the radial turbine wheel, the development of the forming technique for a large, complex-shaped component as well as the development of a high strength and refractory material to achieve a turbine inlet temperature (TIT) of 1350 • C is required [1,25,39,[82][83][84]86]. Takatori et al [1] used for fabrication of radial turbine wheel Si 3 N 4 with additions of 5 wt% Y 2 O 3 and 5 wt% MgAl 2 O 4 (spinel) as additives.…”