Wyniki 1-1 spośród 1 dla zapytania: authorDesc:"Włodzimierz Bogdano wicz"

Crystallographic orientation of aircraft engines turbine blades made of CMSX-4 single crystal nickel superalloy

Czytaj za darmo! »

The aircraft engines turbine blades are considered to be so-called Flight Safety Parts (FSP). They are subject to exceptional requirements related to the production process and quality control. They feature narrow dimensional tolerances and perfect surface quality. Requirements with regard to metallurgical purity, permissible casts’ gas and shrinkage porosity, crystallographic orientation, phase composition and relative volume of strengthening phases as well as heat resistance and high-temperature creep resistance are also strict. Single crystal blades of nickel superalloys belong to the group of products most difficult to produce and meeting strictest reliability requirements [1, 2]. Blades of the first turbine stages and guide vanes made of nickel and cobalt superalloys are subject to continual modification both in terms of their chemical composition, heat treatment as well as manufacturing technology. The manufacture of precise casts of single crystal blades of complex shape of the blade and locking piece is a difficult process, belonging to highly advanced technologies. This applies also to the technology of ceramic moulds exposed to especially difficult conditions, including increased time of interaction with a liquid metal. Single crystal blades feature the highest hightemperature creep resistance as compared with blades obtained in the process of directional crystallisation or conventional casts of microstructure composed of equiaxial grains [2÷5]. Single crystal superalloys’ properties depend on the crystallographic direction taken for studies. Hence the assessment of single crystal casts’ quality is related to determination of their crystallographic orientation, which provides the basis for mechanical properties analysis. It has been assumed on the basis of literature review, that the value of the angle of direction [001] deviation from the angle of single crystal superalloys growth cannot exceed 15°.[...]

 Strona 1