含三角对称分布共晶团复合陶瓷力学性能研究

Mechanical properties of composite ceramics containing triangular symmetric eutectic colonies

从Al2O3/ZrO2(4Y)自生复合陶瓷棒状共晶团的生长机理出发,研究了三角对称分布棒状共晶团的力学性能。基于相互作用直推法,先求得三角对称分布棒状共晶团每一组分的力学性能,然后通过坐标变换求得了整个棒状共晶团的力学性能。对棒状共晶团进行了随机均匀化处理,在考虑Al2O3块晶和ZrO2颗粒夹杂的情况下,求解了复合陶瓷的力学性能。计算中将Al2O3块晶视为椭球,通过三主轴比值的变化近似地模拟了任意形状的Al2O3块晶夹杂;计算了三个主轴的长度比变化时对复合陶瓷材料弹性性质的影响,并与实验结果进行了比较。研究表明:三角对称分布棒状共晶团每一组分呈横观各向同性,其弹性模量与ZrO2纤维的体积含量呈线性关系;三角对称分布棒状共晶团亦为横观各向同性,其在垂直[0001]晶向的平面内力学性质是完全对称的,与平面内坐标选取无关;随Al2O3块晶三个主轴长度比的变化,弹性模量的最大值与最小值相差3.1%。

Based on growth mechanism of rod-shaped eutectic colonies in the Al2O3/ZrO2(4Y) self-growing composite ceramic,the mechanical properties of triangular symmetric eutectic colonies are studied.Firstly,the mechanical properties of components of the eutectic colony are obtained by applying the interaction direct derivative estimate.Secondly,the properties of the entire eutectic colony are got through coordinate conversion method.Finally,the statistical properties of the eutectic colony are calculated,and the mechanical properties of the composite ceramics are obtained considering the Al2O3 lump eutectic and ZrO2 spherical grains.The Al2O3 lump eutectics are considered as ellipsoids with three principal axes.The influences are calculated when the ratio of the three principal axes changed.And the theoretical calculation results are good agreement with the experiments.The main conclusions are as follows.The component part of the eutectic colony is transverse isotropy and its Young’s modulus is linear relation with the content of ZrO2 fiber.The eutectic colony is also transverse isotropy and its mechanical properties are symmetric in the normal plane of orientation [0001].Its mechanical properties are independent of the coordinate systems.The discrepancy of the Young’s modulus is 3.1% when the ratio of the three principal axes changes.