Study On Microstructure And Mechanical Properties Of Rare Earth Tungsten Plate

With the advance of science and technology,tungsten and tungsten alloy materials are widely used in nuclear industry,medical screening and other fields.But tungsten materials also have a lot of shortcomings,for example,tungsten plate in the process of processing can produce fracture,gap and so on.By adding rare earth elements to improve the performance of tungsten alloy,enable it to comply with the relevant indicators and demand,become one of research hotspots at home and abroad.On the basis of the research,three different components were designed,the microstructure of the sintered samples and the mechanism of the edge crack were analyzed.According to the properties of the material,the rolling process was improved.Finally,3 pieces of rare earth tungsten plate with a thickness of about 4mm were prepared.The reason of the corner crack of the finished product is analyzed,and the improving method of the rolling process is put forward.The tungsten plates were annealed at 1250??1350??1450?and 1550?.And the XRD,metallography,EBSD analysis and observation were carried out on the sintered samples?rolled samples and annealed samples.The results show that the XRD analysis shows that the three components of tungsten plate microstructure similar wave figure,because of solid solution of Re and W,the content of rare earth elements is too little.Cracking analysis indicates that Uneven deformation of metal rolling pieces and adding rhenium tungsten processing difficulty,degree of strain hardening increased,leading to corner crack phenomenon occurs,therefore should improve the temperature of the bloom and reduce the hardening of the process,ensure the relative density of sintering billet is above 94%,etc.Metallographic analysis shows that the addition of Re elements has obvious refinement of the tungsten matrix.Combined with the tungsten plate hardness test and microstructure analysis results show:the recrystallization temperature of W-La₂O₃-Y₂O₃-ZrO₂-3Re is 1350?-1450?,the recrystallization temperature of W-La₂O₃-Y₂O₃-ZrO₂-5Re is 1450?,the recrystallization temperature of W-La₂O₃-Y₂O₃-ZrO₂ is 1350?.Tensile test shows that adding rare earth tungsten rhenium element can improve the bonding force between grain size and grain size,makes the tungsten-rhenium alloy has very good elongation under the condition of tensile.EBSD analysis showed that:with the increasing of rhenium content,the recrystallization temperature of tungsten plate,along the alpha line orientation texture distribution becomes more uniform,the gamma texture orientation line strength is more and more weak.Three components of tungsten plate after rolling at the same time in{001}<110>near have strong texture,after annealing{111}<1-21>texture are reduced,when the texture intensity lower stable according to BCC metal recrystallization mechanism for recrystallization,both common explains the three components of tungsten plate recrystallization temperature of different root causes.EBSD analysis and metallographic observation and hardness test to determine the recrystallization temperature of photograph echo,and on the basis of the former two are complementary and perfect,from the Angle of texture,explained the effects of rhenium in the rare earth tungsten plate.Through studying rare earth tungsten plate and analyzing its microstructure and texture evolution process,aimed at establishing tungsten annealing process,for meeting the nuclear industry and medical shielding performance requirements in the field of tungsten products.