Papers by Author: Udo Fritsching

Abstract: A high Zn content Al-Zn-Mg-Cu alloy was prepared by spray forming process and the precipitate behavior and microstructure of the extruded alloy were also investigated. The precipitate sequence of the spray-formed alloy could be described as “α-solid solution → GPI zone → GPII zone (also called Metastable ′ )→ Stable  (MgZn2)” during artificial ageing treatment. In the early stage of artificial ageing treatment, the GPI zone was the main strengthening phase and kept coherent relationship with the matrix. With the increasing of ageing time, ′ phase dominate strengthening phase and kept semi-coherent relationship with the matrix. With the further increasing of ageing time,  phase took the place of ′ phase, and dominated the strengthening phase in the alloy. The grain size of the spray deposit is finer than that of cast alloys. The ultimate tensile strength of the alloy is over 810MPa in peak ageing condition.

Abstract: To minimize the distortion potential of bearing steels, 100Cr6 steel has been spray formed for the manufacture of ring shape components in this study. Structure characteristics of the spray formed bearing steel have been investigated. Evaluation of distortion of bearing components after machining and heat treatment have been made in comparison with continuous cast material. Spray forming has been approved to be an alternative approach to conventional continuous casting for the production of homogeneous 100Cr6 bearing steel of lower distortion potential.