Effects Of B On The Snoek Relaxation Behavior And Microstructure Evolution In TiNb Alloys

With the development of technology, the damping property which means the abilityto absorb energies of viberation and noise is required more and more in many industryfields. Varieties of high damping materials have been studying and applying inpractical industry or daily life since last century. However, the high damping propertyof the most materials developed at early time are usually obtained by sacrificing theirstructures, the damping property will decrease till disappear, which means the usagelife will be short. In Snoek relaxation process, the damping property obtained by thejump of small size interstitial atoms among the octahedral sites. Due to not damagingthe material structure, it can keep a relatively high damping property for a long timeand draw attention nowadays. H, O and N atoms are deeply studied as interstitialatoms. However, H, O and N atoms should be added as compounds. Compared withthis, B atoms can be added as substance, the addition will be more direct and precisely,providing a method to develop new system of high damping alloys.Melting and powder metallurgy are two methods to produce alloys. In this work,these two methods are used to make Nb-B and Ti-Nb-B alloys respectively. Thedamping property, phase constitution and microstructure are observed and analyzedby DMA, XRD, Om, SEM and TEM. The feasibility of that B is used as interstitialatom to participate in Snoek relaxation is analyzed. The relation between dampingproperty and microstructure of alloys is established.The results indentify:(1) B atoms can be used as interstitials participating in Snoekrelaxation. The damping capacities and peak temperatures are relatively high in Nb orTiNb.(2) Before achieving the solid solubility of B in Nb, the matrix is Nbsolid-solution, the damping capacity will be the largest when the concentration of Breaches the solid solubility. Compouds will appear if B is added continuously, it willhinder the relaxation process, resulting in the decrease of damping capacity. Snoekpeaks of TiNbB become broad.(3) The concentration of B doesn’t affect peaktemperature the active energy in this work.