Tesis doctoral de LLuis Gimeno Fabra
The manufacturing process and properties of various cr-re alloys have been investigated in this work to replace pt alloys used currently in the satellite thruster combustion chambers. This thesis has been supported by the corporate research center of eads and tutored by the technical university of catalonia. the studies carried out in the past on the re effect on the mechanical properties of refractory alloys resulted in the industrial application of mo-re and w-re alloys. Cr-re alloys have been studied at a fundamental level indicating an improvement of the mechanical properties of the alloys containing re. Other properties related to its potential application in satellite thrusters were not characterized and an industrial manufacturing process for cr-re alloys does not exist, hence the motivation for this phd. in this work cr-re alloys were manufactured initially by means of powder metallurgy. Their mechanical properties improved with increasing re content verifying the results of the few literature references available. High purity cr-18at%re and cr-35at%re alloys were produced by melting and casting by a specific procedure. Heterogeneity problems in cr-18re alloys were reduced by inoculation of the melt with ce, pr and sc. mechanical properties of the high purity cr-re alloys improve significantly over the powder metallurgical alloys. Compressive elastic limit of both cr-18 and cr-35re alloys at room temperature is over 800 mpa and compressive deformation is possible up to 70% without formation of surface cracks. Elastic limit at 1400°c is over 140 mpa both under compression and tension. Fracture under tension is mixed transgranular and intergranular up to 1200°c. Above this fracture becomes intergranular, characterized by very little plasticity. Best ductility under tension is obtained between 600 and 1000°c with a deformation to fracture of about 10%. resistance of the alloys to oxidation and nitruration was characterized up to 1700 °c. Tests reve
Datos académicos de la tesis doctoral «Design, manufacture and properties of cr-re alloys for apllication in satellite thrusters.«
- Título de la tesis: Design, manufacture and properties of cr-re alloys for apllication in satellite thrusters.
- Autor: LLuis Gimeno Fabra
- Universidad: Politécnica de catalunya
- Fecha de lectura de la tesis: 30/10/2006
Dirección y tribunal
- Director de la tesis
- Marcos Juan Anglada Gomila
- Tribunal
- Presidente del tribunal: Antonio Mateo garcia
- rolf Buetje (vocal)
- francesc Díaz gonzález (vocal)
- johannes Vicek (vocal)