The Wettability And Interfacial Reactions Of Zr-based Alloy Melt On SiC And W In Gravity Environment

Experiments under microgravity environment are very important for the development of new materials, technology and some basic theory. However, there are rarely chances to do experiments in space, thus it is necessary to do many simulated experiments on the ground in advance. In this paper, the wetting behaviors of different positions between molten Zr_41.2Ti_13.8Cu_12.5Ni_10.0Be_22.5 alloy and SiC substrate was studied on the ground. The wetting interfaces were examined by SEM, XRD and EPMA and the SiC particle reinforced Zr_41.2Ti_13.8Cu_12.5Ni_10.0Be_22.5/SiC alloy composite was prepared. The interface reaction between Zr_50.5Cu_36.45Ni_4.05Al₉ alloy melt and W was investigated too. All the experiments will prepare for microgravity experiments. The research work mainly includes the following aspects:Firstly, the wetting processes of Zr_41.2Ti_13.8Cu_12.5Ni_10.0Be_22.5 melts being on and under SiC substrate respectively were studied. The wetting angles of both became smaller and their wetting radius became larger gradually with increase of temperature and extension of holding time. The alloy melts on SiC substrates possess smaller wetting angles and larger radius, compared with the alloy melts under SiC substrates.Secondly, the wetting process of molten Zr_41.2Ti_13.8Ni_10.0Cu_12.5Be_22.5 alloy placing on vertical SiC substrate has been investigated. It was showed that, with increase of the temperature and extension of the time, the distance that the alloy melt spreading down was much more than that alloy melt spreading up and the shape of the alloy melt became irregular. It indicates that gravity has a great effect on the wetting behavior between Zr_41.2Ti_13.8Ni_10.0Cu_12.5Be_22.5 alloy melt and vertical SiC substrate.Thirdly, the interfacial reactions between the molten Zr_41.2Ti_13.8Cu_12.5Ni_10.0Be_22.5 alloy and SiC substrate were studied. It results show that the wetting behaviors belong to reactive wetting. The reaction products on the Zr_41.2Ti_13.8Ni_10.0Cu_12.5Be_22.5/ SiC interfaces were ZrC and TiC.Fourthly,on the basis of the investigation of the wettability and interfacial reactions between the molten Zr_41.2Ti_13.8Cu_12.5Ni_10.0Be_22.5 alloy and SiC substrate, the SiC particle reinforced Zr_41.2Ti_13.8Ni_10.0Cu_12.5Be_22.5 alloy matrix composite was prepared. The distribution of SiC particle in composite material was investigated. It was found that, in the vertical direction of the alloy melt, the distribution of SiC particles was uneven. There were more SiC particles in the upper parts, while there were less SiC particles in the lower parts. The reason is that the density of the SiC is smaller than that of the alloy melt.Fifthly, the Zr_50.5Cu_36.45Ni_4.05Al₉ alloy which had a W stick inside was prepared. After the sample was cut lengthways, the interface of the Zr_50.5Cu_36.45Ni_4.05Al₉ alloy/W was observed. It was found that there was a new W-Zr phase in the Zr_50.5Cu_36.45Ni_4.05Al₉/W interface. Because the high density of the W-Zr phase, it sank into the downside of the sample. Thus it caused the case that, from top to bottom, the amount of the W-Zr phase became more and more.