XRMON EXPERIMENT ON MASER12 SOUNDING ROCKET DEVOTED TO THE X-RAY RADIOGRAPHIC OBSERVATION OF GROWTH PROCESS UNDER MICROGRAVITY

摘要

Structural material properties are strongly related to their solidification microstructures, so that a precise control of theirformation and selection are crucial in engineering. As most of the phenomena involved during solidification aredynamic, in situ and real-time X-ray imaging should be retained as the method of choice for investigating thesolidification front evolution of metallic alloys grown from the melt. On Earth, natural convection in the melt is themajor source of various disturbing effects. Solidification under microgravity is an efficient way to eliminate buoyancyand convection to provide benchmark data for the validation of models and numerical simulations. In addition, acomparative study of solidification experiments carried out on Earth and in space can also enlighten the effects ofgravity. In the frame of the ESA - MAP programme entitled XRMON, an experimental set-up has been developed toperform directional solidification in microgravity conditions with in situ X-ray radiography observation. In the first partof this paper, we will present a brief review of some effects induced by gravity on the solidification process andinvestigated by mean of synchrotron X-ray radiography at ESRF (European Synchrotron Radiation Facility). In thesecond part of this paper, we will describe the XRMON-GF setup, as well as its first flight on-board MASER 12sounding rocket mission. The last part is dedicated to some preliminary results obtained during the MASER mission, soas to show the large capabilities of this experimental set-up in terms of thermal behaviour, as well as X-ray observation.