Development Of High Temperature Liquid Metal Oscillating Viscometer With Magnetic Confinement

Viscosity is one of the most sensitive physical property to the structure of liquids.So viscosity is an important indirect method to study the inherent structure of liquid metals and their solidification processes.The external magnetic field has been an important tool in controlling the solidification process,as well as influencing the structure for metallic materials.Most measurements of the viscosity of liquid metals use some form of oscillating viscometer.Studying and improving this kind of viscometer and further utilizing the viscosity measurements confined in the magnetic field can provide a powerful support for these research on the structure of liquid metals,the process of solidification and the material modification under the magnetic field.Moreover,it provides a prominent scientific significance for the development of materials science and condensed matter physics.Based on the above background,in this paper,a high temperature liquid metal viscometer with magnetic confinement has been studied.The main contents and results are as follows:1.A new high temperature liquid metal viscometer has been developed.Compared with the former imported viscometer,the new viscometer improves the measurement temperature range from 1000? to 1500? and the heating rate increases a lot,thus extending the scope of test samples and decreasing the required test time.Through the ring permanent magnet inside and outside,the new viscometer can measure the viscosity of liquid metals under the adjustable horizontal magnetic field.Furthermore,a new alterable magnetic field viscometer design is put forward creatively.In this design,the magnetic field is generated through coil winding,so the magnetic direction can achieve 360-degree adjustment and the magnetic induction intensity can be controlled more flexibly and conveniently.The novel position sensitive detector can increase the efficiency of measurement.By improving overall structure of the device,the vacuum degree and the stability of the viscometer is also enhanced.2.An upper-computer software is developed independently based on the Qt development platform.Compared with the original software,the new software possesses simple and intuitive graphical user interface;the compatibility and stability are greatly improved.The operating steps are simplified,which makes the detection easier operation.The method that depends on the time difference to adjust zero position shows more operability and higher accuracy.3.According to the viscosity results of water with different volumes,it has been found that the volume of sample should be 60-70%of crucible during the detection.If the sample volume is less than this extent,the error will increase,otherwise,the sample would overflow at high temperature.Besides,the detection results vary obviously with the material types of the crucible due to the wettability between water and crucible.But when measuring the viscosity of liquid metals,the wettability of the crucible has little effect,because the wettability between liquid metals and crucible would be different as high temperature and the components of alloys.According to the measurement results of water and cooper,the precision of the new viscometer can be controlled under 5%.Therefore,the new viscometer can meet the demands of scientific research.