一种单晶高温合金的弹性性能的各向异性

Anisotropy of Elasticity of a Ni Base Single Crystal Superalloy

以一种第一代单晶高温合金为实验材料,利用〈001〉〈100〉和〈011〉〈110〉(2个指数分别为一次和二次取向)2种取向的单晶料板,采用敲击共振法测试了从室温到1100℃范围内第1种试样的Young’s模量和剪切模量及第2种试样的剪切模量,根据测试结果,计算出单晶高温合金的3个弹性常数C11、C12和C44,从而得到单晶高温合金各个取向的Young’s模量和剪切模量。绘制了Young’s模量和剪切模量的最大值及最小值的三维取向分布图,分析了弹性模量随晶体取向的变化规律。当一次取向沿着〈001〉和〈111〉时,剪切模量在面内具有各向同性。当一次取向沿着〈011〉时,剪切模量随着二次取向的变化而显著改变,二次取向为〈110〉时具有最小值,二次取向为〈100〉时具有最大值。

The anisotropy of elasticity of single crystal superalloy is essential to understand its mechanical behavior,e.g.calculating the vibration frequency of turbine blade and avoiding resonance during operation.However,it’s difficult to calculate the stiffness constants of single crystal superalloy by theory methods.In this work,one simple experimental method is employed to determine the stiffness constants.The slabs of a first generation single crystal superalloy in two orientations〈001〉〈100〉and〈011〉〈110〉are employed to measure the Young’s modulus and shear modulus of this alloy.The Young’s modulus and shear modulus of the first specimen and the shear modulus of the second specimen are measured by resonance method from room temperature to 1100℃.The three stiffness constants C11,C12 and C44 of this superalloy are calculated from the measured moduli.The Young’s modulus and shear modulus in any orientation can be calculated based on the stiffness constants.Further,the 3 D distribution map of Young’s modulus and maximum and minimum of shear modulus related to primary orientation can be drawn,so the distribution feature of modulus in 3 D space can be acquired conveniently.When the primary orientations are along〈001〉and〈111〉,the shear modulus in plane is isotropy with secondary orienta-tion.When the primary orientation is along〈011〉,the shear modulus demonstrates significant anisotropy with secondary orientation,the shear modulus reaches minimum with secondary orientation〈110〉,while the maximum is obtained in secondary orientation〈100〉.