Preparation And Mechanical Properties Of Glass/Tungsten Composites

Glass possesses high sound velocity(5.0~6.0km/s)and good plastic under high temperature,which has the potential to apply in shaped charge liner.However,the relative low density results in limited penetration ability.In order to solve this problem,it is feasible to add tungsten,which has high density(19.3g/cm~3),into glass.Thus,it is of great significance to investigate glass/tungsten composite on the preparation and mechanical properties for the application of the shaped charge liner.In this paper,glass/tungsten composite with different tungsten content were prepared by the method of non-pressure sintering and hot pressing sintering.The influences of pressureless sintering method,sintering time,sintering temperature and hot pressing sintering temperature and other process parameters of glass/tungsten composite tissue were studied as well.The optimized preparation method of glass/tungsten composite with different tungsten content was obtained by measuring density and observing microstructure.High temperature dynamic mechanical properties of glass/tungsten composites with different W contents were tested by using a separate Hopkinson pressure bar system with a synchronous device.Moreover,the effects of different tungsten content on dynamic properties of glass/tungsten composite were investigated.Furthermore,the deformation and failure mechanism of glass/tungsten composite were discussed.As for non-pressure sintering,the optimized forming pressure of 20vol%tungsten/glass composite is 250MPa while that of 50vol%tungsten/glass composite is300MPa.The synthesizing time is 3h.However,relative density of the tungsten/glass composite prepared by non-pressure sintering is merely 82.73%.As for hot pressing sintering,the tungsten/glass composite with compact structure was obtained due to that the method promotes the densification during sintering.The optimized sintering temperature of 20vol%tungsten/glass composite,33vol%tungsten/glass composite,50vol%tungsten/glass composite is 750??775??800?separately and the highest relative density reaches 98.94%,97.74%and 97.03%.However,when the tungsten content increases to 67vol%,the relative density is merely 74.39%,indicating that it is unable to get compact tungsten/glass composite by hot pressing sintering.When the temperature is between 500?~750?,the strain of tungsten/glass composite with different tungsten shows an increasing tendency and the composites change from brittle state to plastic state with the increased temperature.When the testing temperature reaches 775?,tungsten/glass composite are unable to endure loading.When the tungsten content of tungsten/glass composite increases from 20vol%~50vol%,the brittle plastic transition temperature of composites decreases gradually and the plastic state temperature range of composites decreases as well.When the tungsten content of tungsten/glass composite increases from20vol%~50vol%,the deformation and failure mechanism varies.When the tungsten content is 20vol%,the deformation and cracks propagation of composites are mainly in glass phase.However,with the increase of tungsten,the deformation mode changes from the glass phase dominated deformation,deformation coordination of tungsten to tungsten phase and glass phase codominant deformation.When the tungsten content is 50vol%,tungsten/glass composite failure mode is changed to the interaction of micro cracks in the glass phase,and interface cracks between the glass phase and tungsten phase.