Joachim Hausmann

Materials and design concepts for high performance compressor components

Abstract High-performance compressors with increased pressure ratios require sophisticated materials solutions and design concepts. Reduced weight and increased strength and stiffness are the major requirements for highly stressed fan blades in future aircraft engines. Two different materials and design approaches will be discussed in the paper, namely local reinforcement of the titanium fan blades by using titanium matrix composites (TMCs) and by partly replacing the bulk titanium fan blade by fiber reinforced plastics (hybrid concept). While the TMCs significantly improve the mechanical properties of the fan blades, the hybrid blades can contribute to considerable weight savings. Blings (=bladed rings) offer high potential in weight savings of the entire compressor and require TMCs in particular for elevated temperature applications that are relevant in the higher stages of the compressor.

Optimisation of the Fatigue Resistance of Metal Matrix Composites

Fiber reinforced titanium matrix composites (TMCs) are attractive materials for future aerospace applications. Reinforcement of Ti alloys with SiC fibers leads to a significant increase on strength and stiffness, especially under high stress loading or at elevated temperatures. Mechanical properties of TMCs are strongly influenced by thermal residual stresses (TRS). A reduction of TRS leads to an increase in fully reversed high cycle fatigue resistance of TMCs at room temperature. Reduction of TRS can be easily obtained by prestraining during single tension loading of TMCs in the as processed condition.