Specifikace parametrů litiny s lupínkovým grafitem pro použití při výrobě vakuových pump

Abstract

The presented Diploma thesis deals with specification improvement of grey cast iron properties to improve its suitability for vacuum pumps production. The theoretical part deals with cast irons and their microstructure. Furthermore it discusses the methods for microstructure evaluation, factors influencing the microstructure and the influence of microstructure on machinability and wear resistance of the material and parts made out of this material. The practical part of the thesis describes practical application of grey cast iron in RV vacuum pumps, the critical part of the pump and problem with pump seizure which is the material related. There was carried out an analysis of material microstructure, of chemical composition and of surface properties of finished parts. Based on the findings, an enhanced specification of basic material microstructure was made to improve pumps reliability. This specification was incorporated in internal Edwards specification for quality requirements of this material.