【作者】 陈辉；

【导师】 曹晓舟；

【作者基本信息】 东北大学 ， 冶金资源循环科学与工程， 2020， 硕士

【摘要】 随着核电技术的发展,人们对于防辐射领域的研究也在持续深入。10B有很大的热中子吸收截面,含有10B的材料既可以大量俘获热中子又能保留所产生的大量气体,以此防止控制组件的肿胀;W同样具有较好的防辐射性能,不仅对中子有慢化的作用,同时对γ射线有良好的屏蔽效果、WB2作为10B和W的化和物,兼具上述两者的优点,因此在现阶段成为防辐射材料的重要研究对象。本文以WB2为主要原料,采用金属浸渗和粉末冶金两种方法得到含硼复合材料,并对其致密度、相组成、表面形貌、断口形貌及力学性能进行了探索性研究。研究结果如下:(1)采用金属无压浸渗法得到高体积分数WB2/Al复合材料,制备步骤包括预制体的真空预烧结和预制体的金属无压浸渗。得到的最佳制备工艺条件为:TiB2添加量为10%,NH4HCO3添加量为0%,预制体的真空预烧结温度和时间分别为:1580℃,1h;金属无压浸渗温度和时间分别为:1100℃,2h,升温速率为10℃/min。此条件下得到的样品力学性能最佳,抗折强度达到476.50MPa,断裂韧性达到 13.42MPa·m1/2。使用X射线衍射、扫描电子显微镜对复合材料的表面及断口进行了表征。结果表明:金属铝液很好的浸渗进入WB2基体且在基体中分布均匀,二者结合强度较好,样品断裂形式表现为穿晶断裂与沿晶断裂共存;(2)采用粉末冶金法得到WB2-Al基复合材料,制备的流程包括高能球磨混料和真空热压烧结。得到的最佳制备工艺条件为:热压烧结温度和时间分别为575℃,1h,升温速率为10℃/min,WB2的添加量为45%。此条件下得到的样品力学性能最佳,抗折强度达到603.82MPa,断裂韧性达到11.12MPa·m1/2。使用X射线衍射、扫描电子显微镜对WB2-Al基复合材料的表面及断口进行了表征。结果表明:增强相WB2粉体在铝基体中分布总体比较均匀,增强体与基体界面结合良好,样品断裂形式表现为穿晶断裂与沿晶断裂共存;(3)采用粉末冶金法得到WB2-Ti基复合材料,制备的流程包括高能球磨混料和真空热压烧结。得到的最佳制备工艺条件为:热压烧结温度和时间分别为1400℃,1h,WB2的添加量为30%,升温速率为10℃/min。此条件下得到的样品力学性能最佳,抗弯强度达到619.65MPa,断裂韧性达到12.57MPa·m12。使用X射线衍射、扫描电子显微镜对WB2-Ti基复合材料的表面进行了表征。结果表明:增强相WB2粉体在钛基体中分布总体比较均匀,增强体与基体界面结合良好,断口形貌表现为以穿晶断裂的形式为主。更多还原

【Abstract】 With the development of nuclear power technology,people’s research in the field of radiation protection continues to deepen.10B has a large thermal neutron absorption cross section.The material containing 10B can capture a large number of gases while capturing thermal neutrons,thereby preventing the swelling of the control components.W also has better radiation protection performance,not only it has a slowing effect on neutrons,and has a good shielding effect on gamma rays.WB2 is a chemical compound of 10B and W,which has the advantages of both of them.Therefore,it has become an important research object of radiation protection materials at this stage.In this paper,WB2 was used as the main raw material,and the boron-containing composites were obtained by metal infiltration and powder metallurgy.The densities,phase composition,surface morphology,fracture morphology and mechanical properties were investigated.The research results are as follows:(1)A high volume fraction WB2/Al composite is obtained by metal pressureless infiltration.The preparation steps include vacuum pre-sintering of the preform and metal pressure infiltration of the preform.The optimum preparation conditions are as follows:TiB2 is added in 10%,NH4HCO3 is added in 0%,and the vacuum pre-sintering temperature and time of the preform are:1580℃,1 h;the metal pressureless infiltration temperature and time are respectively:1100℃,2 h,the heating rate was 10℃/min.The mechanical properties of the samples obtained under these conditions were the best,the flexural strength reached 476.50MPa,and the fracture toughness reached 13.42MPa·m1/2.The surface and fracture of the composite were characterized by X-ray diffraction and scanning electron microscopy.The results show that the metal aluminum solution is well infiltrated into the WB2 matrix and distributed evenly in the matrix.The bonding strength of the two is good.The fracture form of the sample shows the coexistence of transgranular fracture and intergranular fracture;(2)The WB2-Al matrix composite material is obtained by powder metallurgy method,and the preparation process includes high energy ball mill mixing and vacuum hot pressing sintering.The optimum preparation conditions were as follows:the hot pressing sintering temperature and time were 575℃ 1 h,the heating rate was 10℃/min,and the WB2 was added in 45%.The mechanical properties of the samples obtained under these conditions were the best,the flexural strength reached 603.82MPa,and the fracture toughness reached 11.12 MPa·m 1/2.The surface and fracture of WB2-Al matrix composites were characterized by X-ray diffraction and scanning electron microscopy.The results show that the distribution of the WB2 powder in the aluminum matrix is relatively uniform,and the interface between the reinforcement and the matrix is well.The fracture mode of the sample is characterized by the existence of transgranular fracture and intergranular fracture;(3)The WB2-Ti matrix composite material is obtained by powder metallurgy,and the preparation process includes high-energy ball milling and vacuum hot pressing sintering.The optimum preparation conditions were as follows:the hot pressing sintering temperature and time were 1400℃,1 h,the addition amount of WB2 was 30%,and the heating rate was 10℃/min.The mechanical properties of the samples obtained under these conditions were the best,the flexural strength reached 619.65MPa,and the fracture toughness reached 12.57MPa·m1/2.The surface of the WB2-Ti matrix composite was characterized by X-ray diffraction and scanning electron microscopy.The results show that the distribution of the WB2 powder in the titanium matrix is relatively uniform,and the interface between the reinforcement and the matrix is well.The fracture morphology is mainly in the form of transgranular fracture.更多还原